Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

High prevalence of sexually transmitted infections and risk factors among HIV-positive individuals in Yunnan, China

Background Yunnan has the highest rates of HIV in China. Other treatable sexually transmitted infections (STIs) are associated with accelerated HIV transmission and poor ART outcomes, but are only diagnosed by syndromic algorithms. Methods We recruited 406 HIV-positive participants for a cross-sectional study (204 ART-naive and 202 receiving ART). Blood samples and first-voided urine samples were collected. Real-time polymerase chain reaction methods were used for diagnosing Chlamydia trachomatis (CT), Neisseria gonorrhea (NG) and Mycoplasma genitalium (MG). Syphilis and herpes simplex virus type 2 (HSV-2) tests were also performed. Results Among the 406 participants, the overall prevalence of STIs was 47.0% and 45.1% in ART-naive individuals and 49.0% in individuals receiving ART, respectively. The testing frequencies were 11.6% (11.8% vs. 11.4%), 33.2% (29.4% vs. 37.1%), 3.2% (3.4% vs. 3.0%), 2.0% (3.4% vs. 0.5%) and 4.7% (6.4% vs. 3.0%) for active syphilis, HSV-2, CT, NG and MG, respectively. The percentage of multiple infections in both groups was 10.8% (22/204) in ART-naive participants and 9.9% (20/202) in participants receiving ART. Female sex, an age between 18 and 35 years, ever injecting drugs, homosexual or bisexual status, HIV/HBV coinfection, and not receiving ART were identified as risk factors. Self-reported asymptomatic patients were not eliminated from having a laboratory-diagnosed STI. Conclusions The STI prevalence was 47.0% (45.1% vs. 49.0%), and HSV-2, syphilis and MG were the most common STIs in HIV-infected individuals. We found a high prevalence (6.4%) of MG in ART-naive individuals. HIV-positive individuals tend to neglect or hide their genital tract discomfort; thus, we suggest strengthening STI joint screening and treatment services among HIV-infected individuals regardless of whether they describe genital tract discomfort.

High-resolution melting analysis identifies reservoir hosts of zoonotic Leishmania parasites in Tunisia

Background Leishmaniasis is endemic in Tunisia and presents with different clinical forms, caused by the species Leishmania infantum, Leishmania major, and Leishmania tropica. The life cycle of Leishmania is complex and involves several phlebotomine sand fly vectors and mammalian reservoir hosts. The aim of this work is the development and evaluation of a high-resolution melting PCR (PCR-HRM) tool to detect and identify Leishmania parasites in wild and domestic hosts, constituting confirmed (dogs and Meriones rodents) or potential (hedgehogs) reservoirs in Tunisia. Methods Using in vitro-cultured Leishmania isolates, PCR-HRM reactions were developed targeting the 7SL RNA and HSP70 genes. Animals were captured or sampled in El Kef Governorate, North West Tunisia. DNA was extracted from the liver, spleen, kidney, and heart from hedgehogs (Atelerix algirus) (n = 3) and rodents (Meriones shawi) (n = 7) and from whole blood of dogs (n = 12) that did not present any symptoms of canine leishmaniasis. In total, 52 DNA samples were processed by PCR-HRM using both pairs of primers. Results The results showed melting curves enabling discrimination of the three Leishmania species present in Tunisia, and were further confirmed by Sanger sequencing. Application of PCR-HRM assays on reservoir host samples showed that overall among the examined samples, 45 were positive, while seven were negative, with no Leishmania infection. Meriones shawi were found infected with L. major, while dogs were infected with L. infantum. However, co-infections with L. major/L. infantum species were detected in four Meriones specimens and in all tested hedgehogs. In addition, multiple infections with the three Leishmania species were found in one hedgehog specimen. Sequence analyses of PCR-HRM products corroborated the Leishmania species found in analyzed samples. Conclusions The results of PCR-HRM assays applied to field specimens further support the possibility of hedgehogs as reservoir hosts of Leishmania. In addition, we showed their usefulness in the diagnosis of canine leishmaniasis, specifically in asymptomatic dogs, which will ensure a better evaluation of infection extent, thus improving elaboration of control programs. This PCR-HRM method is a robust and reliable tool for molecular detection and identification of Leishmania and can be easily implemented in epidemiological surveys in endemic regions. Graphical Abstract

Anemia and undernutrition in intestinally parasitized schoolchildren from Gakenke district, Northern Province of Rwanda

Background Rwanda is a sub-Saharan country, where intestinal parasite infections, anemia and undernutrition coexist. The purpose of this research is to study the relationship between intestinal parasite infections and undernutrition/anemia to clarify the priorities of intervention in the rural area of Gakenke district in the Northern Province of Rwanda. Materials and methods A total of 674 students from Nemba I School, participated in a cross-sectional study, in which their parasitological and nutritional status were analysed. Statistical analysis was performed by χ2 test, univariate analysis and Odds ratios (OR). Results A total of 95.3% of children presented intestinal parasitism, most of whom (94.5%) infected by protozoa and 36.1% infected by soil-transmitted helminths (STH), with Trichuris trichiura (27.3%) being the most prevalent. Multiple infections were found to be high (83.8%), with protozoa and STH co-infections in 30.6%. STH infections were mainly of low/moderate intensity. Neither infection nor STH infection of any intensity profile, was significantly related to anemia. In addition, STH infection, regardless of the intensity profile, was not associated with stunting, underweight or thinness. There was no difference between genders nor among ages in odds of anemia and nutritional status in STH-infected schoolchildren. Conclusion Multiparasitism remains high among Rwandan schoolchildren and is likely to cause nutritional problems. This work emphasizes the importance of keeping up health programs to reduce the prevalence of infection.

Roles of extended human papillomavirus genotyping and multiple infections in early detection of cervical precancer and cancer and HPV vaccination

Background The aim of the study was to investigate the risk of human papillomavirus (HPV) genotyping particularly vaccine genotypes and multiple infections for cervical precancer and cancer, which might contribute to developing genotype-specific screening strategy and assessing potential effects of HPV vaccine. Methods The HPV genotypes were identified using the Seq HPV assay on self-collected samples. Hierarchical ranking of each genotype was performed according to positive predictive value (PPV) for cervical intraepithelial neoplasia 2/3 or worse (CIN2+/CIN3+). Multivariate logistic regression model was used to estimate the odds ratios (ORs) with 95% confidence interval (CI) of CIN2+ according to multiplicity of types and vaccine types. Results A total of 2811 HPV-positive women were analyzed. The five dominant HPV genotypes in high-grade lesions were 16/58/52/33/18. The overall ranking orders were HPV16/33/35/58/31/68/18/ 56/52/66/51/59/45/39 for CIN2+ and HPV16/33/31/58/45/66/52/18/35/56/51/68/59/39 for CIN3+. The risks of single infection versus co-infections with other types lower in the hierarchy having CIN2+ were not statistically significant for HPV16 (multiple infection vs. single infection: OR = 0.8, 95%CI = 0.6-1.1, P = 0.144) or other genotypes (P > 0.0036) after conservative Bonferroni correction. Whether HPV16 was present or not, the risks of single infection versus multiple infection with any number (2, ≥2, or ≥ 3) of types for CIN2+ were not significantly different. In addition, HPV31/33/45/52/58 covered by nonavalent vaccine added 27.5% of CIN2, 23.0% of CIN3, and 12.5% of cancer to the HPV16/18 genotyping. These genotype-groups were at significantly higher risks than genotypes not covered by nonavalent vaccine. Moreover, genotypes covered by nonavalent vaccine contributed to 85.2% of CIN2 lesions, 97.9% of CIN3 and 93.8% of cancers. Conclusions Partial extended genotyping such as HPV33/31/58 but not multiplicity of HPV infections could serve as a promising triage for HPV-positive self-samples. Moreover, incidence rates of cervical cancer and precancer were substantial attributable to HPV genotypes covered by current nonavalent vaccination.

Coinfection with PEDV and BVDV Induces Inflammatory Bowel Disease Pathway Highly Enriched in PK-15 Cells

Background: From the 1078 diarrhea stools tested in our survey from 2017 to 2020 in local area of China, PEDV was the key pathogen which was closely related to the death of diarrhea piglets. Besides, co-infection of PEDV-positive samples with BVDV reached 17.24%. Although BVDV infection in swine is typically subclinical, the effect of PEDV and BVDV coinfection on disease severity and the potential molecular mechanism of coinfection with these two viruses remain unknown.Methods: In this study, we developed a model of coinfection with porcine epidemic diarrhea virus (PEDV) and bovine viral diarrhea virus (BVDV) in PK15 cells, and a tandem mass tag (TMT) combined with LC–MS/MS proteomic approach was used to identify differential protein expression profiles. Additionally, we take the drug experiments to explore the inflammatory response induced by PEDV or BVDV mono- or coinfection.Results: A total of 1094, 1538, and 1482 differentially expressed proteins (DEPs) were identified upon PEDV monoinfection, BVDV monoinfection and PEDV/BVDV coinfection, respectively. KEGG pathway analysis revealed that PEDV and BVDV coinfection leaded to a highly significantly enrichment of inflammatory bowel disease (IBD) pathway. In addition, the NF-κB signaling pathway was more intensively activated by PEDV and BVDV coinfection, which induced higher production of inflammatory cytokines, than PEDV or BVDV monoinfection.Conclusions: Our study indicated that cattle pathogens might play synergistic roles in the pathogenesis of porcine diarrhea disease, which might also improve our understanding of the pathogenesis of multiple infections in diarrhea disease.

Preserved Omicron Spike specific antibody binding and Fc-recognition across COVID-19 vaccine platforms

Despite the dramatic spread of Omicron globally, even among highly vaccinated populations, death rates have not increased concomitantly. These data argue that alternative immune mechanisms, beyond neutralization, may continue to confer protection against severe disease. Beyond their ability to bind and block infection, antibodies contribute to control and clearance of multiple infections via their ability to direct antiviral immunity via Fc-effector mechanisms. Thus, here we probed the ability of vaccine induced antibodies, across three COVID-19 vaccines, to drive Fc-effector activity against Omicron. Despite the significant loss of IgM, IgA and IgG binding to the Omicron Receptor Binding Domain (RBD) across BNT162b2, mRNA-1273, and CoronaVac vaccines, stable isotype binding was observed across all of these vaccines to the Omicron Spike. Compromised RBD binding IgG was accompanied by a significant loss of cross RBD-specific antibody Fcγ-receptor binding by the CoronaVac vaccine, but preservation of RBD-specific FcγR2a and Fcγ3a binding across the mRNA vaccines. Conversely, Spike-specific antibodies exhibited persistent binding to Fcγ-receptors, across all three vaccines, albeit higher binding was observed with the mRNA vaccines, marked by a selective preservation of FcγR2a and Fcγ3a binding antibodies. Thus, despite the significant to near complete loss of Omicron neutralization across several vaccine platforms against Omicron, vaccine induced Spike-specific antibodies continue to recognize the virus and recruit Fc-receptors pointing to a persistent capacity for extra-neutralizing antibodies to contribute Omicron disease attenuation.

Serology and Amplicon Deep Sequencing of MSP1-Block 2 Haplotypes as New Tools for Plasmodium Vivax Infections

Background: Relapses of Plasmodium vivax (P. vivax) infections are major causes of malaria morbidity, and tools for distinguishing relapses from reinfections are needed in malaria endemic areas. Methods: Herein, a panel of plasmas of 72 P. vivax-infected pregnant women, of whom 31 had had at least a recurrence of P. vivax infection, was used in a serology for IgM and IgG against 6 P. vivax-merozoite surface protein-1 (P. vivax-MSP1-Block 2) haplotype-specific peptides, in order to identify re-expositions to same haplotypes in the recurrences during the pregnancy. In parallel, we used the amplicon deep sequencing (ADS) with P. vivax-MSP1-Block 2 amplicons of the in eight blood samples of non-pregnant P. vivax-infected patients to identify multi or monoclonal infections based on MSP1-Block-2 haplotypes, and to quantify the reads of different haplotypes between those with multiclonal infections. We synthetized a new panel of overlapping peptides mapping each one of the six P. vivax-MSP1-Block 2 haplotypes and we validated with new IgM and IgG serology. Results: Most pregnant women presented IgM that recognized more than one peptide, thus indicating multiple infections by P. vivax-MSP1-Block 2 haplotypes. The same IgM anti-peptides remained in several women in the recurrent episodes most likely indicates re-exposure to the same haplotype of MSP1 Block 2. The IgG reactivity the IgM to IgG switch were low. The ADS using next-generation sequencing (NGS) identified multi- and monoinfection by P. vivax-MSP1-Block 2 haplotypes. Of eight patients, two of them had had the first P. vivax-infection. Monoinfections with P. vivax-MSP1-Block 2 haplotypes were observed in two prime-infected patients and three of patients with previous malaria. In all P. vivax-MSP1-Block 2 haplotype-monoinfected patients, the reactivity of IgM was observed only against overlapped peptides of the same haplotype detected in ADS, while for IgG, no reactivity was observed for any of the peptides of the same haplotype or the others.We were able to identify multiclonal infections through three haplotypes of P. vivax MSP1 Block 2 in three remaining patients, among which, there was always one majority haplotype that predominated with more of 95% of high-quality reads. The levels of haplotype-specific IgM in the serology correlated with the read ratios of each haplotype, but IgG levels not, including in one of the multiclonal infections, a minority haplotype was recognized with higher levels of IgG than that of the majority one. Conclusion: Our findings suggest that the combination of ADS and serology for P. vivax-MSP1-Block 2 haplotypes may be used as a new tool for distinguishing reinfections from relapses in malaria.

Recruitment of Ostrea chilensis (Philippi, 1844) in Foveaux Strait, Southern New Zealand

<p>This research evaluates fundamental ecological processes to facilitate an understanding of recruitment in Ostrea chilensis from Foveaux Strait, southern New Zealand. Foveaux Strait represents an extreme habitat for oysters that differs to the sheltered nearshore, muddy habitats of most other oyster populations. O. chilensis exhibits the extreme end of brooding strategies in Ostreinae, does not form extensive reefs, and comprises putative self-recruiting populations. The Foveaux Strait oyster fishery is nationally important. Recurrent disease mortality in these populations has put greater onus on understanding recruitment. To evaluate the strength of a recruit-per-spawner relationship in oysters, seasonality in the settlement of larvae was determined. Most recruitment in any given year, over a 6-year period, occurred in the austral spring and summer (November to February). Fishery-wide, recruitment varied significantly between years, with most variation (50.8%) explained by a year effect that represents the combined influences of climatic and biological conditions. Spawner densities and fishery areas explain further variation (13.8% and 11.6%, respectively), with further 2-way interactions between these factors. Recruits-per-spawner declined serially over time, despite similar or increasing densities of spawning-sized oysters. Average recruitment was lowest when spawner densities were highest; this suggests a more complex relationship between recruitment and density that has implications for management of this oyster fishery. Recruitment to the O. chilensis fishery declined abruptly to low levels in 2010 and remained low until 2017. Relatively high spawning-stock sizes over this period had previously supported high recruitment. Density and oyster mortality from Bonamia exitiosa (a proxy for one or more infections) and their two-way interaction were the main determinants of recruitment. The highest recruitment occurred at times of low mortality and low density, suggesting reduced effects of disease on gametogenesis and reduced disease transmission. The contributions of climate factors were minor; however, a 3-way interaction between oyster density, mortality, and climate is likely to drive variation in recruitment. Pathobiomes (multiple infections in populations) may be important determinants of shellfish recruitment and population dynamics. This research evaluates the hypothesis of self-recruitment from distributions of recruit densities around an isolated natal population, and from the relationship between recruitment and brooding-sized oyster densities. Distance from the natal population, direction along or across the tidal current, or brooders did not predict recruit densities. Recruit distributions imply greater dispersal and larval mixing than previously reported. The swift tidal currents and possibility of more variable pelagic larval durations may enhance mixing and connectivity between populations in Foveaux Strait. Post-settlement mortality is the primary determinant of spatial structure in Foveaux Strait oysters. Productive fishery areas comprise mostly stable substrates of shells, sand, and gravel, with no or little other epifauna. Most (66.8%) post-settlement survivors were on the heavy shells of both live and dead O. chilensis, which suggests an unusual recruit-adult relationship based on survival rather than settlement. Recruits and 1+ year spat grew larger and had lower mortality at eastern sites with the lowest exposure to oceanic swells and putative lowest sediment movement. Moreover, recruits on spat collectors also grew larger and had lower mortality at heights ≥ 12 cm than those 2 cm off the seabed. This research suggests the effects of disease on brooding percentages and thereby larval supply may be the main determinant of the variation in recruitment in O. chilenesis, and the spatial structure of oyster populations in Foveaux Strait shaped by abiotic as well as biotic post-settlement mortality.</p>

Recruitment of Ostrea chilensis (Philippi, 1844) in Foveaux Strait, Southern New Zealand

<p>This research evaluates fundamental ecological processes to facilitate an understanding of recruitment in Ostrea chilensis from Foveaux Strait, southern New Zealand. Foveaux Strait represents an extreme habitat for oysters that differs to the sheltered nearshore, muddy habitats of most other oyster populations. O. chilensis exhibits the extreme end of brooding strategies in Ostreinae, does not form extensive reefs, and comprises putative self-recruiting populations. The Foveaux Strait oyster fishery is nationally important. Recurrent disease mortality in these populations has put greater onus on understanding recruitment. To evaluate the strength of a recruit-per-spawner relationship in oysters, seasonality in the settlement of larvae was determined. Most recruitment in any given year, over a 6-year period, occurred in the austral spring and summer (November to February). Fishery-wide, recruitment varied significantly between years, with most variation (50.8%) explained by a year effect that represents the combined influences of climatic and biological conditions. Spawner densities and fishery areas explain further variation (13.8% and 11.6%, respectively), with further 2-way interactions between these factors. Recruits-per-spawner declined serially over time, despite similar or increasing densities of spawning-sized oysters. Average recruitment was lowest when spawner densities were highest; this suggests a more complex relationship between recruitment and density that has implications for management of this oyster fishery. Recruitment to the O. chilensis fishery declined abruptly to low levels in 2010 and remained low until 2017. Relatively high spawning-stock sizes over this period had previously supported high recruitment. Density and oyster mortality from Bonamia exitiosa (a proxy for one or more infections) and their two-way interaction were the main determinants of recruitment. The highest recruitment occurred at times of low mortality and low density, suggesting reduced effects of disease on gametogenesis and reduced disease transmission. The contributions of climate factors were minor; however, a 3-way interaction between oyster density, mortality, and climate is likely to drive variation in recruitment. Pathobiomes (multiple infections in populations) may be important determinants of shellfish recruitment and population dynamics. This research evaluates the hypothesis of self-recruitment from distributions of recruit densities around an isolated natal population, and from the relationship between recruitment and brooding-sized oyster densities. Distance from the natal population, direction along or across the tidal current, or brooders did not predict recruit densities. Recruit distributions imply greater dispersal and larval mixing than previously reported. The swift tidal currents and possibility of more variable pelagic larval durations may enhance mixing and connectivity between populations in Foveaux Strait. Post-settlement mortality is the primary determinant of spatial structure in Foveaux Strait oysters. Productive fishery areas comprise mostly stable substrates of shells, sand, and gravel, with no or little other epifauna. Most (66.8%) post-settlement survivors were on the heavy shells of both live and dead O. chilensis, which suggests an unusual recruit-adult relationship based on survival rather than settlement. Recruits and 1+ year spat grew larger and had lower mortality at eastern sites with the lowest exposure to oceanic swells and putative lowest sediment movement. Moreover, recruits on spat collectors also grew larger and had lower mortality at heights ≥ 12 cm than those 2 cm off the seabed. This research suggests the effects of disease on brooding percentages and thereby larval supply may be the main determinant of the variation in recruitment in O. chilenesis, and the spatial structure of oyster populations in Foveaux Strait shaped by abiotic as well as biotic post-settlement mortality.</p>