Pathogens, Volume 9, Issue 2 (February 2020) – 83 articles

Staphylococcus aureus is an opportunistic bacterium causing a wide variety of diseases. Biofilm formation of Staphylococcus aureus is of primary public and animal health concern. The purposes of the present study were to investigate the ability of Staphylococcus aureus isolated from animals, humans, and food samples to form biofilms and to screen for the presence of biofilm-associated and regulatory genes. In total, 55 Staphylococcus aureus isolated from sheep mastitis cases (n = 28), humans (n = 19), and from food matrices (n = 8) were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The ability of Staphylococcus aureus for slime production and biofilm formation was determined quantitatively. A DNA microarray examination was performed to detect adhesion genes (icaACD and biofilm-associated protein gene (bap)), genes encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), regulatory genes (accessory gene regulator (agr) and staphylococcal accessory regulator (sarA)), and the staphylococcal cassette chromosome mec elements (SCCmec). Out of 55 Staphylococcus aureus isolates, 39 (71.0%) and 23 (41.8%) were producing slime and biofilm, respectively. All Staphylococcus aureus strains isolated from food showed biofilm formation ability. 52.6% of the Staphylococcus aureus strains isolated from sheep with mastitis, and 17.9% of isolates from humans, were able to form a biofilm. Microarray analysis typed the Staphylococcus aureus into 15 clonal complexes. Among all Staphylococcus aureus isolates, four of the human isolates (21.1%) harbored the mecA gene (SCCmec type IV) typed into 2 clonal complexes (CC22-MRSA-IV and CC80-MRSA-IV) and were considered as methicillin-resistant, while two of them were slime-producing. None of the isolates from sheep with mastitis harbored the cna gene which is associated with biofilm production. The fnbB gene was found in 100%, 60% and 40% of biofilm-producing Staphylococcus aureus isolated from food, humans, and sheep with mastitis, respectively. Three agr groups were present and agr group III was predominant with 43.6%, followed by agr group I (38.2%), and agr group II (18.2%). This study revealed the capacity of Staphylococcus aureus isolates to form biofilms and highlighted the genetic background displayed by Staphylococcus aureus isolates from different sources in Algeria. Full article

Currently used Brucella vaccines, Brucella abortus strain 19 and RB51, comprises of live attenuated Brucella strains and prevent infection in animals. However, these vaccines pose potential risks to recipient animals such as attenuation reversal and virulence in susceptible hosts on administration. In this context, recombinant subunit vaccines emerge as a safe and competent alternative in combating the disease. In this study, we formulated a divalent recombinant vaccine consisting of Omp25 and L7/L12 of B. abortus and evaluated vaccine potential individually as well as in combination. Sera obtained from divalent vaccine (Omp25+L7/L12) immunized mice group exhibited enhanced IgG titers against both components and indicated specificity upon immunoblotting reiterating its authenticity. Further, the IgG1/IgG2a ratio obtained against each antigen predicted a predominant Th2 immune response in the Omp25+L7/L12 immunized mice group. Upon infection with virulent B. abortus 544, Omp25+L7/L12 infected mice exhibited superior Log10 protection compared to individual vaccines. Consequently, this study recommends that simultaneous immunization of Omp25 and L7/L12 as a divalent vaccine complements and triggers a Th2 mediated immune response in mice competent of providing protection against brucellosis. Full article

Typhoid fever is a potentially severe and occasionally life-threatening bacteraemic illness caused by Salmonella enterica serovar Typhi (S. Typhi). In Pakistan, an outbreak of extensively drug-resistant (XDR) S. Typhi cases began in November 2016. We report on a five-year-old boy who contracted enteric fever while travelling in Pakistan and was diagnosed after returning to Italy in September 2019. Blood culture isolated Salmonella enterica serovar Typhi that was XDR to all first-line antibiotics, including ceftriaxone and fluoroquinolones. Empiric therapy was switched to meropenem, and the patient recovered completely. Whole-genome sequencing showed that this isolate was of haplotype H58. The XDR S. Typhi clone encoded a chromosomally located resistance region and harbored a plasmid encoding additional resistance elements, including the blaCTX-M-15 extended-spectrum β-lactamase and the qnrS fluoroquinolone resistance gene. This is the first case of typhoid fever due to XDR S. Typhi detected in Italy and one of the first paediatric cases reported outside Pakistan, highlighting the need to be vigilant for future cases. While new vaccines against typhoid are in development, clinicians should consider adapting their empiric approach for patients returning from regions at risk of XDR S. Typhi outbreak with typhoid symptoms. Full article

In Europe, Ixodes ricinus ticks transmit pathogens such as Borrelia burgdorferi sensu lato and tick-borne encephalitis virus (TBEV). In addition, there is evidence for transmission to humans from I. ricinus of Anaplasma phagocytophilum, Babesia divergens, Babesia microti, Babesia venatorum, Borrelia miyamotoi, Neoehrlichia mikurensis, Rickettsia helvetica and Rickettsia monacensis. However, whether infection with these potential tick-borne pathogens results in human disease has not been fully demonstrated for all of these tick-borne microorganisms. To evaluate the available evidence for a causative relation between infection and disease, the current study analyses European case reports published from 2008 to 2018, supplemented with information derived from epidemiological and experimental studies. The evidence for human disease causality in Europe found in this review appeared to be strongest for A. phagocytophilum and B. divergens. Nonetheless, some knowledge gaps still exist. Importantly, comprehensive evidence for pathogenicity is lacking for the remaining tick-borne microorganisms. Such evidence could be gathered best through prospective studies, for example, studies enrolling patients with a fever after a tick bite, the development of specific new serological tools, isolation of these microorganisms from ticks and patients and propagation in vitro, and through experimental studies. Full article

Methylobacterium spp. are emerging opportunistic premise plumbing pathogens. Human infections linked to premise plumbing provide evidence of their routes of infection. Cells of a collection of representative strains of different Methylobacterium species were tested for hydrophobicity by contact angle, adherence and biofilm formation on different plumbing materials, and temperature tolerance (50–60 °C); characteristics shared by OPPPs. Methylobacterium spp. strains were shown to grow in drinking water, have high cell-surface hydrophobicity, adhere to pipe surface materials, form biofilms, and survive exposure to high (60° C) temperatures. It can be concluded that Methylobacterium spp. strains share traits in common with other opportunistic premise plumbing pathogens (OPPPs). Full article

Novel Coronavirus (2019-nCoV) is an emerging pathogen that was first identified in Wuhan, China in late December 2019. This virus is responsible for the ongoing outbreak that causes severe respiratory illness and pneumonia-like infection in humans. Due to the increasing number of cases in China and outside China, the WHO declared coronavirus as a global health emergency. Nearly 35,000 cases were reported and at least 24 other countries or territories have reported coronavirus cases as early on as February. Inter-human transmission was reported in a few countries, including the United States. Neither an effective anti-viral nor a vaccine is currently available to treat this infection. As the virus is a newly emerging pathogen, many questions remain unanswered regarding the virus’s reservoirs, pathogenesis, transmissibility, and much more is unknown. The collaborative efforts of researchers are needed to fill the knowledge gaps about this new virus, to develop the proper diagnostic tools, and effective treatment to combat this infection. Recent advancements in plant biotechnology proved that plants have the ability to produce vaccines or biopharmaceuticals rapidly in a short time. In this review, the outbreak of 2019-nCoV in China, the need for rapid vaccine development, and the potential of a plant system for biopharmaceutical development are discussed. Full article

Streptococcus suis serotype 2 is an important porcine bacterial pathogen and zoonotic agent causing sudden death, septic shock and meningitis. These pathologies are the consequence of an exacerbated inflammatory response composed of various mediators including interleukin (IL)-1β. Elevated levels of the toxin suilysin (SLY) were demonstrated to play a key role in S. suis-induced IL-1β production. However, 95% of serotype 2 strains isolated from diseased pigs in North America, many of which are virulent, do not produce SLY. In this study, we demonstrated that SLY-negative S. suis induces elevated levels of IL-1β in systemic organs, with dendritic cells contributing to this production. SLY-negative S. suis-induced IL-1β production requires MyD88 and TLR2 following recognition of lipoproteins. However, the higher internalization rate of the SLY-negative strain results in intracellularly located DNA being recognized by the AIM2 inflammasome, which promotes IL-1β production. Finally, the role of IL-1 in host survival during the S. suis systemic infection is beneficial and conserved, regardless of SLY production, via modulation of the inflammation required to control bacterial burden. In conclusion, this study demonstrates that SLY is not required for S. suis-induced IL-1β production. Full article

Although sturgeon production by aquaculture has increased worldwide, a major factor limiting its expansion are infectious diseases, although few data about viral diseases are available however. This review provides a rapid overview of viral agents detected and described to date. Following a general introduction on viral diseases are four sections arranged by virus classification: sturgeon nucleocytoplasmic large DNA viruses, herpesviruses, white sturgeon adenovirus 1, and other viruses. Molecular diagnosis is currently the best tool to detect viral diseases, since cell culture isolation is not yet applicable for the detection of most sturgeon viruses. Full article

Cucumber mosaic virus (CMV), with extremely broad host range including both monocots and dicots around the world, belongs to most important viral crop threats. Either natural or genetically constructed sources of resistance are being intensively investigated; for this purpose, exhaustive knowledge of molecular virus-host interaction during compatible and incompatible infection is required. New technologies and computer-based “omics” on various levels contribute markedly to this topic. In this work, two cucumber cultivars with different response to CMV challenge were tested, i.e., sensitive cv. Vanda and resistant cv. Heliana. The transcriptomes were prepared from both cultivars at 18 days after CMV or mock inoculation. Subsequently, four independent comparative analyses of obtained data were performed, viz. mock- and CMV-inoculated samples within each cultivar, samples from mock-inoculated cultivars to each other and samples from virus-inoculated cultivars to each other. A detailed picture of CMV-influenced genes, as well as constitutive differences in cultivar-specific gene expression was obtained. The compatible CMV infection of cv. Vanda caused downregulation of genes involved in photosynthesis, and induction of genes connected with protein production and modification, as well as components of signaling pathways. CMV challenge caused practically no change in the transcription profile of the cv. Heliana. The main differences between constitutive transcription activity of the two cultivars relied in the expression of genes responsible for methylation, phosphorylation, cell wall organization and carbohydrate metabolism (prevailing in cv. Heliana), or chromosome condensation and glucan biosynthesis (prevailing in cv. Vanda). Involvement of several genes in the resistant cucumber phenotype was predicted; this can be after biological confirmation potentially applied in breeding programs for virus-resistant crops. Full article

Acanthamoeba is a genus of free-living amoebae widely distributed in nature, associated with the development of encephalitis and keratitis. Despite the fact that it is common to find genotype T5 in environmental samples, only a few cases have been associated with clinical cases in humans. The wide distribution of Acanthamoeba, the characteristic of being amphizoic and the severity of the disease motivate researchers to focus on the isolation of these organisms, but also in demonstrating direct and indirect factors that could indicate a possible pathogenic potential. Here, we performed the characterization of the pathogenic potential of an Acanthamoeba T5 isolate collected from a water source in a hospital. Osmo- and thermotolerance, the secretion of proteases and the effect of trophozoites over cell monolayers were analyzed by different methodologies. Additionally, we confirm the secretion of extracellular vesicles (EVs) of this isolate incubated at two different temperatures, and the presence of serine and cysteine proteases in these vesicles. Finally, using atomic force microscopy, we determined some nanomechanical properties of the secreted vesicles and found a higher value of adhesion in the EVs obtained at 37 °C, which could have implications in the parasite´s survival and damaging potential in two different biological environments. Full article

Piscine orthoreovirus-1 (PRV-1) can cause heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar), but the line of events from infection, pathologic change, and regeneration has not been thoroughly described. In this study, the cellular localization and variation of PRV-1 RNA and protein levels were analyzed at different times post-exposure in experimentally infected Atlantic salmon. Immunohistochemistry, flow cytometry, and Western blot were used for assessment of the presence of the PRV-1 σ1 protein, while RT-qPCR and in situ hybridization were performed for viral RNA. Histopathologic evaluation demonstrated that PRV-1 infection induced heart lesions typical of HSMI, such as severe epicarditis and myocarditis with degeneration of cardiomyocytes, necrosis, and diffuse cellular infiltration. PRV-1 infection of erythrocytes and the peak viral plasma level preceded virus presence in cardiomyocytes and hepatocytes. Arginase-2-positive, macrophage-like cells observed in the heart indicated possible polarization to M2 macrophages and the onset of regenerative processes, which may contribute to the recovery from HSMI. The virus was cleared from regenerating heart tissue and from hepatocytes, but persisted in erythrocytes. Full article

The study’s aim was to analyze the population structure of enterococci causing human invasive infections in a medium-sized Argentinian Hospital coincidental with a 5 year-period of increased recovery of antibiotic resistant enterococci (2010–2014). Species identification (biochemical testing/MALDI-TOF-MS), antimicrobial susceptibility (disk-diffusion) and clonal relatedness (PFGE/MLST/BAPS) were determined according to standard guidelines. β-lactamase production was determined by a nitrocefin test and confirmed by PCR/sequencing. The isolates were identified as Enterococcus faecalis and Enterococcus faecium at a 2:1 ratio. Most of the E. faecalis isolates, grouped in 25 PFGE-types (ST9/ST179/ST236/ST281/ST388/ST604/ST720), were resistant to high-levels (HLR) of gentamicin/streptomycin. A ST9 clone (bla⁺/HLR-gentamicin) was detected in patients of different wards during 2014. E. faecium isolates were grouped in 10 PFGE-types (ST25/ST18/ST19/ST52/ST792), with a low rate of ampicillin resistance. Five vancomycin-resistant E. faecium, three vanA (ST792/ST25) and two vanB (ST25) were detected. The ST25 clone carried either vanA or vanB. The recovery of a bla⁺-ST9-E. faecalis clone similar to that described in the late 1980s in Argentina suggests the possibility of a local hidden reservoir. These results reflect the relevance of local epidemiology in understanding the population structure of enterococci as well as the emergence and spread of antimicrobial resistance in predominant enterococcal clonal lineages. Full article

Colletotrichum gloeosporioides, an important phytopathogenic fungus, mainly infects tropical fruits and results in serious anthracnose. Previous studies have shown that melanin biosynthesis inhibitor can inhibit the melanization of the appressoria of Magnaporthe grisea and Colletotrichum orbiculare, resulting in limited infection of the hosts. In this study, we identified and characterized a scytalone dehydratase gene (CgSCD1) from C. gloeosporioides which is involved in melanin synthesis. The CgSCD1 gene deletion mutant ΔCgscd1 was obtained using homologous recombination. The ΔCgscd1 mutant showed no melanin accumulation on appressoria formation and vegetative hyphae. Furthermore, the virulence of ΔCgscd1 was significantly reduced in comparison with the wild-type (WT) strain. Further investigations showed that the growth rate as well as germination and appressorium formation of ΔCgscd1 displayed no difference compared to the wild-type and complemented transformant Cgscd1^com strains. Furthermore, we found that the appressorial turgor pressure in the ΔCgscd1 mutant showed no difference compared to that in the WT and Cgscd1^com strains in the incipient cytorrhysis experiment. However, fewer infectious hyphae of ΔCgscd1 were observed in the penetration experiments, suggesting that the penetration ability of nonpigmented appressoria was partially impaired. In conclusion, we identified the CgSCD1 gene, which is involved in melanin synthesis and pathogenicity, and found that the melanization defect did not affect appressorial turgor pressure in C. gloeosporioides. Full article

Fc gamma receptors (FcγRs) are widely expressed on a variety of immune cells and play a myriad of regulatory roles in the immune system because of their structural diversity. Apart from their indispensable role in specific binding to the Fc portion of antibody subsets, FcγRs manifest diverse biological functions upon binding to their putative ligands. Examples of such manifestation include phagocytosis, presentation of antigens, mediation of antibody-dependent cellular cytotoxicity, anaphylactic reactions, and the promotion of apoptosis of T cells and natural killer cells. Functionally, the equilibrium between activating and inhibiting FcγR maintains the balance between afferent and efferent immunity. The γ subunit of the immunoglobulin Fc receptor (FcRγ) is a key component of discrete immune receptors and Fc receptors including the FcγR family. Furthermore, FcγRs exert a key role in terms of crosslinking the innate and adaptive workhorses of immunity. Ablation of one of these receptors might positively or negatively influence the immune response. Very recently, we discovered that FcRγ derived from natural cytotoxicity triggering receptor 1 (NCR1) curtails CD8⁺ T cell expansion and thereby turns an acute viral infection into a chronic one. Such a finding opens a new avenue for targeting the FcγRs as one of the therapeutic regimens to boost the immune response. This review highlights the structural heterogeneity and functional diversity of the ubiquitous FcγRs along with their featured subunit, FcRγ. Full article

Because canine intestinal parasites are considered cosmopolitan, they carry significant zoonotic potential to public health. These etiological agents are routinely diagnosed using microscopic examination commonly used because of its low cost, simple execution, and direct evidence. However, there are reports in the literature on the poor performance of this test due to low to moderate sensitivity resulting from frequent errors, procedures and interpretation. Therefore, to improve the diagnostic efficiency of microscopic examination in veterinary medicine, we developed and evaluated a unique new protocol. This system was tested in a study involving four genera of highly prevalent canine intestinal parasites in an endemic region in São Paulo state, Brazil. Fecal samples from 104 animals were collected for this research. The new protocol had a significantly higher (p < 0.0001) number of positive cases on image data, including parasites and impurities, and was elaborate to test them with the TF-GII/Dog technique, with a moderate agreement and Kappa index of 0.7636. We concluded that the new Prototic Coproparasitological Test for Dogs (PC-Test Dog) allowed a better visualization of the parasitic structures and showed a favorable result for the diagnosis of intestinal parasites in dogs. Full article

Staphylococcus aureus (S. aureus) is a commensal bacterium in the human body; however, the bacterium frequently generates serious inflammation and infectious diseases. Some strains of S. aureus, such as methicillin-resistant Staphylococcus aureus (MRSA), are still a serious problem in public health facilities. Thus, an effective protection strategy is eagerly expected for the prevention and cure of MRSA infection. Here, we report that a specific fraction of an S. aureus lipoprotein (SA-LP) established a protective response against MRSA infection. The fractionated S. aureus lipoprotein SA-LP-F2, which is contained in 30–50 kDa of crude S. aureus lipoprotein (SA-LP-C), effectively activated dendritic cells (DCs) and the SA-LP-F2-pulsed DCs generated IFN-γ+CD4+ T (Th1) and IL-17A+CD4+ T (Th17) cells by in vitro antigen presentation. The SA-LP-F2 immunization upregulated the Th1 and Th17 populations so that MRSA colonization on the skin was suppressed during the challenge phase with MRSA. By following the effector T cell upregulation, the neutrophil function, which was a substantial effector cell against MRSA, was also enhanced in the SA-LP-F2-immunized mice. Finally, we found that the protective effect of SA-LP-F2 immunization was maintained for at least 90 days because the immunized mice continued to show a protective response during the MRSA challenge period. In the MRSA challenge, reactivated Th1 and Th17 populations were maintained in the SA-LP-F2-immunized mice as compared to naive mice. In addition, the neutrophil population was also upregulated in the mice. The memory CD4+ T cell (central memory T; T_CM and effector memory T; T_EM) population was established by SA-LP-F2 immunization and was maintained at higher levels than usual. Taken together, our findings may provide a breakthrough in the establishment of an immunization strategy against MRSA infection. Full article

Introduction: Reliable and cost-effective diagnostics for hepatitis E virus (HEV) infection are necessary. The aim of our study was to investigate which diagnostic test is most accurate to detect HEV infection in immunocompetent and immunosuppressed patients in a real world setting. Patients and Methods: We performed a retrospective analysis of 1165 patients tested for HEV antibodies and HEV PCR at the same time point. Clinical, laboratory and virological data were taken from patient charts. HEV IgA was measured in a subgroup of 185 patients. Results: HEV RNA was detectable in 61 patients (5.2%); most of them (n = 49, 80.3%/n = 43, 70.5%) were HEV IgM+ and IgG+; however, 12 patients (19.6%) were HEV RNA positive/HEV IgM negative and 17 patients (27.8%) were HEV RNA positive/HEV IgG negative. Ten HEV RNA positive patients (16.4%) had neither HEV IgG nor IgM antibodies. Importantly, all of them were immunosuppressed. HEV IgA testing was less sensitive than HEV IgM for HEV diagnosis. Conclusions: HEV infection can be overlooked in patients without HEV specific antibodies. Performing PCR is necessary to diagnose or exclude HEV infection in immunocompromised hosts. In immunocompetent patients, a screening based on HEV antibodies (IgG/IgM) is sufficient. Full article

Although Corynebacterium striatum is part of the human flora, it has recently drawn attention both for its multidrug resistance and its role as an invasive infection/outbreak agent. This cross-sectional study aimed to determine the antimicrobial resistance and clonal relationships among C. striatum strains. In total, 81 C. striatum strains were identified using Phoenix-100^TM (BD, Sparks, MD, USA). The antimicrobial resistance of the strains was determined using the Kirby–Bauer disk diffusion method. Clonal relatedness among the strains was performed via arbitrarily primed polymerase chain reaction (AP-PCR). All 81 C. striatum strains were resistant to penicillin, cefotaxime, ciprofloxacin, and tetracycline, but susceptible to vancomycin and linezolid. The resistance rates to gentamicin, erythromycin, and clindamycin were 34.6%, 79%, and 87.7% respectively. AP-PCR results showed no predominant clone among the C. striatum strains. Corynebacterium striatum is reportedly the cause of an increasing number of invasive infections/outbreaks. Moreover, treatment options are limited. The study showed that vancomycin, linezolid, and gentamicin can be selected for the empirical treatment of C. striatum infections. Although no single-clone outbreak was observed in our hospital, small clonal circulations were observed within some units, indicating cross-contamination. Therefore, a comprehensive infection control program is warranted in future. Full article

Human metapneumovirus (HMPV) is an important human pathogen that, along with respiratory syncytial virus (RSV), is a major cause of respiratory tract infections in young infants. Development of an effective vaccine against Pneumoviruses has proven to be particularly difficult; despite over 50 years of research in this field, no vaccine against HMPV or RSV is currently available. Recombinant chimeric viruses expressing antigens of other viruses can be generated by reverse genetics and used for simultaneous immunization against more than one pathogen. This approach can result in the development of promising vaccine candidates against HMPV, and several studies have indeed validated viral vectors expressing HMPV antigens. In this review, we summarize current efforts in generating recombinant chimeric vaccines against HMPV, and we discuss their potential optimization based on the correspondence with RSV studies. Full article

In the absence of a vaccine, current antibiotic-dependent efforts to reduce the prevalence of Neisseria gonorrhoeae in high prevalence populations have been shown to result in extremely high levels of antibiotic consumption. No randomized controlled trials have been conducted to validate this strategy and an important concern of this approach is that it may induce antimicrobial resistance. To contribute to this debate, we assessed if mass treatment in the related species, Neisseria meningitidis, was associated with the emergence of antimicrobial resistance. To this end, we conducted a historical review of the effect of mass meningococcal treatment programmes on the prevalence of N. meningitidis and the emergence of antimicrobial resistance. We found evidence that mass treatment programmes were associated with the emergence of antimicrobial resistance. Full article

Human papillomavirus (HPV) E6 and E7 oncoproteins are critical for development and maintenance of the malignant phenotype in HPV-induced cancers. These two viral oncoproteins interfere with a plethora of cellular pathways, including the regulation of cell cycle and the control of apoptosis, which are critical in maintaining normal cellular functions. E6 and E7 bind directly with certain components of the Ubiquitin Proteasome System (UPS), enabling them to manipulate a number of important cellular pathways. These activities are the means by which HPV establishes an environment supporting the normal viral life cycle, however in some instances they can also lead to the development of malignancy. In this review, we have discussed how E6 and E7 oncoproteins from alpha and beta HPV types interact with the components of the UPS, and how this interplay contributes to the development of cancer. Full article

Epigenetic reprogramming in macrophages is termed trained innate immunity, which regulates immune tolerance and limits tissue damage during infection. Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. Here, we report that this pathogen harbors a gene that encodes a histone deacetylase-like enzyme (Gc-HDAC) that shares high 3D-homology to human HDAC1, HDAC2 and HDAC8. A Gc-HDAC null mutant was constructed to determine the biologic significance of this gene. The results showed that WT gonococci reduced the expression of host defense peptides LL-37, HBD-1 and SLPI in macrophages when compared to its Gc-HDAC-deficient isogenic strain. The enrichment of epigenetic marks in histone tails control gene expression and are known to change during bacterial infections. To investigate whether gonococci exert epigenetic modifications on host chromatin, the enrichment of acetylated lysine 9 in histone 3 (H3K9ac) was investigated using the TLR-focused ChIP array system. The data showed that infection with WT gonococci led to higher H3K9ac enrichment at the promoters of pro-inflammatory mediators’ genes, many TLRs, adaptor proteins and transcription factors, suggesting gene activation when compared to infection with the Gc-HDAC-deficient mutant. Taken together, the data suggest that gonococci can exert epigenetic modifications on host cells to modulate certain macrophage defense genes, leading to a maladaptive state of trained immunity. Full article

Tuberculosis, caused by Mycobacterium tuberculosis complex bacteria, remains one of the most pressing health problems. Despite the general trend towards reduction of the disease incidence rate, the situation remains extremely tense due to the distribution of the resistant forms. Most often, these strains emerge through the intra-host microevolution of the pathogen during treatment failure. In the present study, the focus was on three serial clinical isolates of Mycobacterium tuberculosis Beijing B0/W148 cluster from one patient with pulmonary tuberculosis, to evaluate their changes in metabolism during anti-tuberculosis therapy. Using whole genome sequencing (WGS), 9 polymorphisms were determined, which occurred in a stepwise or transient manner during treatment and were linked to the resistance (GyrA D94A; inhA t-8a) or virulence. The effect of the inhA t-8a mutation was confirmed on both proteomic and transcriptomic levels. Additionally, the amount of RpsL protein, which is a target of anti-tuberculosis drugs, was reduced. At the systemic level, profound changes in metabolism, linked to the evolution of the pathogen in the host and the effects of therapy, were documented. An overabundance of the FAS-II system proteins (HtdX, HtdY) and expression changes in the virulence factors have been observed at the RNA and protein levels. Full article

Porcine epidemic diarrhea virus (PEDV) is a highly virulent re-emerging enteric coronavirus that causes acute diarrhea, dehydration, and up to 100% mortality in neonatal suckling piglets. Despite this, a safe and effective PEDV vaccine against highly virulent strains is unavailable, making PEDV prevention and control challenging. Lactogenic immunity induced via the gut-mammary gland-secretory IgA (sIgA) axis, remains the most promising and effective way to protect suckling piglets from PEDV. Therefore, a successful PEDV vaccine must induce protective maternal IgA antibodies that passively transfer into colostrum and milk. Identifying variables that influence lymphocyte migration and IgA secretion during gestation and lactation is imperative for designing maternal immunization strategies that generate the highest amount of lactogenic immune protection against PEDV in suckling piglets. Because pregnancy-associated immune alterations influence viral pathogenesis and adaptive immune responses in many different species, a better understanding of host immune responses to PEDV in pregnant swine may translate into improved maternal immunization strategies against enteric pathogens for multiple species. In this review, we discuss the role of host factors during pregnancy on antiviral immunity and their implications for generating protective lactogenic immunity in suckling neonates. Full article

Inactivated whole-virus vaccines are widely used for the control of foot-and-mouth disease (FMD). Their production requires the growth of large quantities of virulent FMD virus in biocontainment facilities, which is expensive and carries the risk of an inadvertent release of virus. Attenuated recombinant viruses lacking the leader protease coding region have been proposed as a safer alternative for the production of inactivated FMD vaccines (Uddowla et al., 2012, J Virol 86:11675-85). In addition to the leader deletion, the marker vaccine virus FMDV LL3B_PVKV3D_YR A₂₄ encodes amino acid substitutions in the viral proteins 3B and 3D that allow the differentiation of infected from vaccinated animals and has been previously shown to be effective in cattle and pigs. In the present study, two groups of six pigs each were inoculated with live FMDV LL3B_PVKV3D_YR A₂₄ virus either intradermally into the heel bulb (IDHB) or by intra-oropharyngeal (IOP) deposition. The animals were observed for 3 or 5 days after inoculation, respectively. Serum, oral and nasal swabs were collected daily and a thorough postmortem examination with tissue collection was performed at the end of the experiment. None of the animals had any signs of disease or virus shedding. Virus was reisolated from only one serum sample (IDHB group, sample taken on day 1) and one piece of heel bulb skin from the inoculation site of another animal (IDHB group, necropsy on day 3), confirming that FMDV LL3B_PVKV3D_YR A₂₄ is highly attenuated in pigs. Full article

Urinary schistosomiasis is a devastating parasitic disease in Nigeria. This study was carried out to investigate the current prevalence, intensity, risk factors and knowledge assessment among some rural communities in southwestern Nigeria. A cross-sectional study was carried out in which a standard urine filtrations technique was used to determine the prevalence and intensity of infection. A well-designed questionnaire was used to collect subject’s data on demographic and socioeconomic characteristics. Of the total 620 urine samples examined, overall 346 (55.81%) were positive with a mean egg intensity (S.D) of 65.60 (59.33) egg/10 mL of urine. Significant differences occurred in the analysis. Males had the highest prevalence and intensity of 224 (61.9%) and 69.20 egg/10 mL of urine, respectively. The 10–14 years age group had the highest prevalence of 65.9% while mean intensity of infection among the age group decreases with increasing age, with the highest mean intensity of infection (80.14 egg/10 mL) recorded among the age group ≤ 4 years. Bivariate logistic regression analysis showed that being age group 10–14 (COR 0.27, 95% CI: 0.09–0.79) and dependent on river (COR 0.67, 95% CI: 0.33–1.33) increased the odd of contracting an infection. Similarly, the knowledge of respondents on urinary schistosomiasis was low. Conclusively, urinary schistosomiasis is still persistent at a very high rate in the study area and appropriate control measure should be deployed. Full article

Atranorin (ATR), is a compound with multidirectional biological activity under different in vitro and in vivo conditions and it is effective as an antibacterial, antiviral, antiprotozoal and anti-inflammatory agent. In the current study, the in vitro as well as in vivo chemotherapeutic effect of ATR as well as its combined efficacy with the existing antibabesial drugs (diminazene aceturate (DA), atovaquone (AV) and clofazimine (CF)) were investigated on six species of piroplasm parasites. ATR suppressed B. bovis, B. bigemina, B. divergens, B. caballi and T. equi multiplication in vitro with IC₅₀ values of 98.4 ± 4.2, 64.5 ± 3.9, 45.2 ± 5.9, 46.6 ± 2.5, and 71.3 ± 2.7 µM, respectively. The CCK test was used to examine ATR’s cytotoxicity and adverse effects on different animal and human cell lines, the main hosts of piroplasm parasites and it showed that ATR affected human foreskin fibroblasts (HFF), mouse embryonic fibroblast (NIH/3T3) and Madin-Darby Bovine Kidney (MDBK) cell viability in a dose-related effect with a moderate selective index. The combined efficacy of ATR with DA, CF, and AV exhibited a synergistic and additive efficacy toward all tested species. In the in vivo experiment, ATR prohibited B. microti multiplication in mice by 68.17%. The ATR-DA and ATR-AV combination chemotherapies were more potent than ATR monotherapy. These results indicate the prospects of ATR as a drug candidate for piroplasmosis treatment. Full article

Rhizosphere bacteria can positively influence plant growth by direct and indirect mechanisms. A total of 112 bacterial strains were isolated from the rhizosphere of rice and tested for plant beneficial activities such as siderophore production, cell-wall-degrading enzyme production, hydrogen cyanide (HCN) production and antifungal activity against rice blast disease fungus. The actinomycetes count was 3.8 × 10⁶ CFU/g soil. Streptomyces strains PC 12, D 4.1, D 4.3 and W1 showed strong growth inhibition of blast disease fungus, Pyricularia sp. (87.3%, 82.2%, 80.0% and 80.5%) in vitro. Greenhouse experiments revealed that rice plants treated with Streptomyces strain PC 12 recorded maximum plant height, root length and root dry weight compared to the control. Taxonomic characterization of this strain on the basis of 16S rRNA gene sequence led to its identification as Streptomyces palmae PC 12. Streptomyces palmae PC 12 may be used as biofertilizer to enhance the growth and productivity of commercially important rice cultivar RD6 and the biocontrol of blast disease fungus. Full article

Latency establishment is the hallmark feature of herpesviruses, a group of viruses, of which nine are known to infect humans. They have co-evolved alongside their hosts, and mastered manipulation of cellular pathways and tweaking various processes to their advantage. As a result, they are very well adapted to persistence. The members of the three subfamilies belonging to the family Herpesviridae differ with regard to cell tropism, target cells for the latent reservoir, and characteristics of the infection. The mechanisms governing the latent state also seem quite different. Our knowledge about latency is most complete for the gammaherpesviruses due to previously missing adequate latency models for the alpha and beta-herpesviruses. Nevertheless, with advances in cell biology and the availability of appropriate cell-culture and animal models, the common features of the latency in the different subfamilies began to emerge. Three criteria have been set forth to define latency and differentiate it from persistent or abortive infection: 1) persistence of the viral genome, 2) limited viral gene expression with no viral particle production, and 3) the ability to reactivate to a lytic cycle. This review discusses these criteria for each of the subfamilies and highlights the common strategies adopted by herpesviruses to establish latency. Full article

Amdoparvovirus and Protoparvovirus are monophyletic viral genera that infect carnivores. We performed surveillance for and sequence analyses of parvoviruses in mustelids in insular British Columbia to investigate parvoviral maintenance and cross-species transmission among wildlife. Overall, 19.1% (49/256) of the tested animals were parvovirus-positive. Aleutian mink disease virus (AMDV) was more prevalent in mink (41.6%, 32/77) than martens (3.1%, 4/130), feline panleukopenia virus (FPV) was more prevalent in otters (27.3%, 6/22) than mink (5.2%, 4/77) or martens (2.3%, 3/130), and canine parvovirus 2 (CPV-2) was found in one mink, one otter, and zero ermines (N = 27). Viruses were endemic and bottleneck events, founder effects, and genetic drift generated regional lineages. We identified two local closely related AMDV lineages, one CPV-2 lineage, and five FPV lineages. Highly similar viruses were identified in different hosts, demonstrating cross-species transmission. The likelihood for cross-species transmission differed among viruses and some species likely represented dead-end spillover hosts. We suggest that there are principal maintenance hosts (otters for FPV, raccoons for CPV-2/FPV, mink for AMDV) that enable viral persistence and serve as sources for other susceptible species. In this multi-host system, viral and host factors affect viral persistence and distribution, shaping parvoviral ecology and evolution, with implications for insular carnivore conservation. Full article