Trends in invasive Haemophilus influenzae serotype b (Hib) disease in England; 2012/13 to 2022/23.

INTRODUCTION: Haemophilus influenzae serotype b (Hib) conjugate vaccines have been highly successful in reducing the Hib disease worldwide. Recently, several European countries have reported an increase in invasive Hib disease. We aimed to describe the epidemiology, clinical characteristics, genomic trends, and outcomes of invasive Hib disease over the past 11 years in England. METHODS: The UK Health Security Agency (UKHSA) conducts national surveillance of invasive H influenzae disease and hosts a national reference laboratory for confirmation and serotyping. General practitioners are contacted to complete a surveillance questionnaire for confirmed Hib cases. Invasive Hib isolates routinely undergo whole genome sequencing. RESULTS: During 2012/13-2022/23, there were 6,881 invasive H. influenzae infections, of which 5,852 (85%) were serotyped; most isolates (4,881, 83%) were non-typeable H. influenzae, followed by Hif (591, 10%), Hie (189, 3%), Hib (118, 2%) and Hia (54, 1.0%). The median age for invasive Hib disease was 51 years and most cases (84%, 99/118) were in adults. Children accounted for 19 cases (16%), including 13 (11%) in <1 year-olds and 6 (5%) in 1-5-year-olds. Bacteraemic pneumonia was the most common diagnosis (66/118, 56%). Hib case-fatality rate was 5.9% (7/118), with the last fatality reported in 2016. Among 64 sequenced strains during 2016/17-2022/2023, most (56/64, 88%) belonged to the CC6 lineage (representing ST6 and single locus variants of ST6). CONCLUSIONS: In England, invasive Hib disease remains rare with no evidence of any increase in incidence and is rarely fatal, affecting mainly adults with underlying conditions, who typically develop pneumonia.

Whole-genome sequencing of multidrug-resistant Klebsiella pneumoniae with capsular serotype K2 isolates from mink in China.

BACKGROUND: Klebsiella pneumoniae is a zoonotic opportunistic pathogen, and also one of the common pathogenic bacteria causing mink pneumonia. The aim of this study was to get a better understanding of the whole-genome of multi-drug resistant Klebsiella pneumoniae with K2 serotype in China. This study for the first time to analyze Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, resistance and virulence genes of Klebsiella pneumoniae in mink. RESULTS: The isolate was Klebsiella pneumoniae with serotype K2 and ST6189 by PCR method. The string test was positive and showed high mucus phenotype. There was one plasmid with IncFIB replicons in the genome. The virulence factors including capsule, lipopolysaccharide, adhesin, iron uptake system, urease, secretory system, regulatory gene (rcsA, rcsB), determinants of pili adhesion, enolase and magnesium ion absorption related genes. The strain was multi-drug resistant. A total of 26  resistance genes, including beta-lactam, aminoglycosides, tetracycline, fluoroquinolones, sulfonamides, amide alcohols, macrolides, rifampicin, fosfomycin, vancomycin, diaminopyrimidines and polymyxin. Multidrug-resistant efflux protein AcrA, AcrB, TolC, were predicted in the strain. CONCLUSION: It was the first to identify that serotype K2 K. pneumonia with ST6189 isolated from mink in China. The finding indicated that hypervirulent and multi-drug resistant K. pneumoniae was exist in Chinese mink. The whole-genome of K. pneumoniae isolates have importance in mink farming practice.

Efficient AAV9 Purification Using a Single-Step AAV9 Magnetic Affinity Beads Isolation.

Adeno-associated viruses (AAVs) have emerged as promising tools for gene therapy due to their safety and efficacy in delivering therapeutic genes or gene editing sequences to various tissues and organs. AAV serotype 9 (AAV9), among AAV serotypes, stands out for its ability to efficiently target multiple tissues, thus holding significant potential for clinical applications. However, existing methods for purifying AAVs are cumbersome, expensive, and often yield inconsistent results. In this study, we explore a novel purification strategy utilizing Dynabeads™ CaptureSelect™ magnetic beads. The AAV9 magnetic beads capture AAV9 with high specificity and recovery between 70 and 90%, whereas the AAVX magnetic beads did not bind to the AAV9. Through continuous interaction with AAVs in solution, these beads offer enhanced clearance of genomic DNA and plasmids even in the absence of endonuclease. The beads could be regenerated at least eight times, and the used beads could be stored for up to six months and reused without a significant reduction in recovery. The potency of the AAV9-purified vectors in vivo was comparable to that of iodixanol purified vectors.

The impact of the bluetongue serotype 3 outbreak on sheep and goat mortality in the Netherlands in 2023.

In September 2023, bluetongue virus serotype 3 (BTV-3) emerged in the Netherlands, infecting over five thousand livestock farms. In sheep, high morbidity and mortality rates were reported that were unlike previously described bluetongue outbreaks. This study aimed to quantify the impact of BTV-3 in the small ruminant population in the Netherlands in 2023. Sheep and goat movement census data and BTV-3 notification data were available from 2020 until the end of 2023. Data were aggregated to farm and week level and mortality indicators were calculated for lambs (<1 year) and adult animals (≥1 year). Population averaged GEE models with a Negative-binomial distribution and a log-link function correcting for repeated measures per farm in time were used to quantify the association between BTV-3 and mortality. In 2023, 2994 sheep farmers and 89 goat farmers notified clinical signs of BTV-3 to the NVWA. During this BTV-3 outbreak period, an additional 55,000 sheep died compared to the same period in 2020-2022. At flock level a high variety in mortality was observed, with a clear increase in mortality in both flocks that were not notified but that were located in infected areas and in flocks of which the farmer notified clinical signs. During the BTV-3 outbreak period, mortality in infected areas increased 4.2 (95 % CI: 4.0-4.3) times in sheep lambs (<1 year) and 4.6 (95 % CI: 4.4-4.8) times in sheep (≥1 year) compared to BTV-3 free areas. Flocks with a confirmed BTV-3 infection that were notified in September showed a 12.8 (95 % CI: 11.4-14.3) times higher mortality in lambs and a 15.1 (95 % CI: 13.7-16.6) times higher mortality in sheep compared to flocks in BTV-3 areas. In flocks of which the farmer notified clinical signs after September, mortality was 4.6 (95 % CI: 4.2-5.0) and 5.6 (95 % CI: 5.1-6.0) times higher in lambs and sheep compared BTV-3 areas respectively. In goats, around 4000 additional deaths were recorded during the BTV-3 outbreak period. In farms that were notified, mortality of goats (≥1 year) was 1.8 (95 % CI: 1.2-2.8) times higher compared to BTV-3 free areas. Since May 2024, multiple BTV-3 vaccines are available in the Netherlands. In June 2024, the first new infections of BTV-3 were confirmed in Dutch sheep flocks. Hopes are that with the possibility to vaccinate, the spread and impact of BTV-3 in the Netherlands will rapidly decline and that losses as observed in 2023 will no longer be seen.

A retrospective study of animal leptospirosis in Kazakhstan.

Objective: The purpose of the paper was to monitor the disease incidence in farm and wild animals in some areas of Kazakhstan, which are most susceptible to leptospirosis, and the typification of isolated pathogens, carried out under the scientific and technical program "Studying the epizootological characteristics of the country territory on particularly dangerous diseases and developing veterinary and sanitary measures to improve their effectiveness" in 2021-2023. Materials and Methods: The material included the reports of veterinary laboratories on leptospirosis in recent years, as well as laboratory tests on samples carried out at the "SANA" research and development enterprise. During this period, 6,701 serum samples from farm animals and 86,651 serum samples from rodents were tested by enzyme-linked immunosorbent assay. Results: The serological results showed antibody titers in the blood of 6.32% of cattle, 5.4% of sheep, 4.2% of horses, and 1.8% of pigs. The highest number of positive samples were found in Turkestan (12.3%), Almaty (11.7%), and Kyzylorda (11.4%) regions. Infection in rodents was lower and ranged from 0.34% to 0.07% during these years. The population of leptospira-causing diseases of animals on the territory of the country is represented by 8 serogroups. Studies in 2022 on the detection of pathogenic leptospires by polymerase chain reaction in 350 samples of blood serum from animals and 350 samples of biomaterial from rodents from different regions of Kazakhstan were negative. Conclusion: Studies conducted as part of this work will help reduce the incidence of disease among the population and animals in Kazakhstan.

Serotype distribution of invasive pneumococcal disease from countries of the WHO Africa, Americas, Eastern Mediterranean, South-East Asia, and Western Pacific regions: a systematic literature review from 2010 to 2021.

Background: Most publications on invasive pneumococcal disease (IPD) serotype distribution are from about 20 countries (Australia, Canada, China, European Union members, Japan, New Zealand, South Korea, and USA). Here, we reviewed the literature among underrepresented countries in the Americas (AMRO), Africa (AFRO), Eastern Mediterranean (EMRO), South-East Asia (SEARO), and Western Pacific (WPRO) WHO regions. Methods: We performed a systematic review of the most recent IPD serotype surveillance publications (from 01/01/2010 to 31/12/2021, Medline/Embase) in those WHO regions. Selection criteria were delineated by contemporality, within-country geographical scope, and number of samples. Reported serotype distributions for each country were stratified by age group, pneumococcal conjugate vaccine (PCV) serotype category (considering undifferentiated serotypes), and PCV program period (pre-PCV, intermediate, or PCVhv [higher valency PCV formulation]). Pre-PCV period pooled data estimated PCV serotype category distribution by age group across WHO regions, while for the PCVhv period, country-level dataset tables were prepared. Results: Of 2,793 publications screened, 107 were included (58 pediatric, 11 adult, 37 all ages, and one comprising every age group). One-third of eligible countries (51/135) published serotype distribution, ranging from 30 to 43% by WHO region. Considering number of samples per WHO region, a few countries prevailed: AMRO (Brazil), AFRO (South Africa, Malawi, and Burkina Faso), and WPRO (Taiwan). In the pre-PCV period, PCV13 formulation serotypes predominated: ranging from 74 to 85% in children and 58-86% in adults in the different WHO regions. The PCVhv period represented half of the most recent IPD surveillance by countries (26/51). Undifferentiated serotypes represented >20% of IPD from most countries (34/51). Conclusion: Ubiquity of undifferentiated serotypes among the publications could constrain estimates of PCV program impact and of serotype coverage for newer PCVhv formulations; consequently, we recommend that countries favor techniques that identify serotypes specifically and, rather than reporting PCV formulation serotype distributions, provide serotype results individually. Systematic review registration: The protocol has been prospectively registered at PROSPERO, identifier: CRD42021278501. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=278501.

A Meta-analysis to Quantify the Risk of Disseminated Gonococcal Infection With Porin B Serotype.

The escalating rates of gonorrhea globally are associated with higher numbers of disseminated gonococcal infection (DGI). Expression of the PorB1A allele of the major outer membrane porin protein, PorB, is associated with DGI. This meta-analysis shows that the odds of PorB1A strains to disseminate is 20.53 compared to PorB1B isolates.

Characterization of Streptococcus pneumoniae isolates obtained from the middle ear fluid of US children, 2011-2021.

Introduction: Pneumococcal conjugate vaccines (PCVs), including higher valency vaccines such as PCV20, have the potential to reduce pediatric otitis media. We assessed serotype distribution, potential PCV coverage, and antimicrobial susceptibility of Streptococcus pneumoniae isolates cultured from middle ear fluid (MEF) of US children age ≤5 years. Methods: S. pneumoniae isolates identified from US hospitals participating in the SENTRY Antimicrobial Surveillance program from 2011 to 2021 were included. Serotypes were determined by in silico analysis based on Pneumococcal Capsular Typing methodology. The percentage of isolates belonging to serotypes included in PCV13 (serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F), PCV15 (PCV13 plus 22F, 33F), and PCV20 (PCV13 plus, 8, 10A, 11A, 12F, 15B, 22F and 33F) was calculated. Antimicrobial susceptibility testing was performed by broth microdilution and interpreted using CLSI criteria. Nonsusceptibility was defined as isolates that were intermediate or resistant to a selected antimicrobial. Results: Among the 199 S. pneumoniae isolates that were identified, 56.8% were from children age <2 years. Six serotypes accounted for around 60% of isolates: 35B (16.6%), 15B (14.6%), 15A (7.5%), 19A (7.5%), 19F (7.5%), and 3 (7.0%). Serotypes included in PCV13, PCV15, and PCV20 accounted for 23.1%, 30.2%, and 54.8% of isolates, respectively. Overall, 45.2% of isolates were penicillin non-susceptible, and 13.6% were MDR, of which 48% were serotype 19A. Seven serotypes (19A, 15A, 15B, 15C, 23A, 33F, and 35B) accounted for the majority of non-susceptible isolates. Discussion: PCVs, particularly PCV20, may prevent a substantial fraction of S. pneumoniae otitis media (OM), including OM due to non-susceptible serotypes. The addition of serotypes 15A, 23A, and 35B would improve coverage against susceptible and non-susceptible pneumococcal OM.

Enterovirus A71 2A-S125A acts as an attenuated vaccine candidate, indicating a universal approach in developing enterovirus vaccines.

Enteroviruses are important human pathogens with diverse serotypes, posing a major challenge to develop vaccines for individual serotypes, the success of polio vaccines in controlling and eradicating polio, along with the recent emergence and high prevalence of enterovirus-caused infectious diseases, highlights the importance of enterovirus vaccine development. Given our previous report on enteroviruses weakened by the 2 A S/T125A mutation, we assessed the potential of the EV-A71 2A-125A mutant as a vaccine candidate to address this challenge. We found that the 2A-125A mutant caused transient mild symptoms, low viral loads, and no significant pathological changes mild pathological changes in hSCARB2-KI mice, producing long-lasting cross-neutralizing antibodies against two EV-A71 wild strains. Pre-exposure to the 2A-125A mutant substantially protected against the EV-A71 Isehara wild-type strain, causing minor pathologies, significantly reducing muscle and lung inflammation, and preventing neurological damage, with reduced viral loads in vivo. Pre-exposure also distinctly suppressed the expression of pro-inflammatory cytokines, correlating to the severity of clinical symptoms. Collectively, the EV-A71 2A-125A mutant was attenuated and could generate a robust and protective immune response, suggesting its potential as a vaccine candidate and global solution for specific enterovirus vaccine development.

Functional Identification and Genetic Analysis of O-Antigen Gene Clusters of Food-Borne Pathogen Yersinia enterocolitica O:10 and Other Uncommon Serotypes, Further Revealing Their Virulence Profiles.

Yersinia enterocolitica is a globally distributed food-borne gastrointestinal pathogen. The O-antigen variation-determined serotype is an important characteristic of Y. enterocolitica, allowing intraspecies classification for diagnosis and epidemiology purposes. Among the 11 serotypes associated with human yersiniosis, O:3, O:5,27, O:8, and O:9 are the most prevalent, and their O-antigen gene clusters have been well defined. In addition to the O-antigen, several virulence factors are involved in infection and pathogenesis of Y. enterocolitica strains, and these are closely related to their biotypes, reflecting pathogenic properties. In this study, we identified the O-AGC of a Y. enterocolitica strain WL-21 of serotype O:10, and confirmed its functionality in O-antigen synthesis. Furthermore, we analyzed in silico the putative O-AGCs of uncommon serotypes, and found that the O-AGCs of Y. enterocolitica were divided into two genetic patterns: (1) O-AGC within the hemH-gsk locus, possibly synthesizing the O-antigen via the Wzx/Wzy dependent pathway, and (2) O-AGC within the dcuC-galU-galF locus, very likely assembling the O-antigen via the ABC transporter dependent pathway. By screening the virulence genes against genomes from GenBank, we discovered that strains representing different serotypes were grouped according to different virulence gene profiles, indicating strong links between serotypes and virulence markers and implying an interaction between them and the synergistic effect in pathogenicity. Our study provides a framework for further research on the origin and evolution of O-AGCs from Y. enterocolitica, as well as on differences in virulent mechanisms among distinct serotypes.

Genetic Characterization of Palyam Serogroup Viruses Isolated in Japan from 1984 to 2018 and Development of a Real-Time RT-PCR Assay for Broad Detection of Palyam Serogroup Viruses and Specific Detection of Chuzan (Kasba) and D'Aguilar Viruses.

We performed whole genome sequencing (WGS) of 15 Palyam serogroup virus (PALV) strains isolated from cattle or Culicoides biting midges in Japan from 1984 to 2018. We found that the PALV strains consisted of Chuzan (Kasba) virus (CHUV), D'Aguilar virus (DAGV), Bunyip Creek virus, and another PALV, Marrakai virus (MARV). The Japanese MARV strains isolated in 1997 were closely related to Australian PALV strains isolated in 1968-1976 in genome segments 2 and 10, but they were most closely related to other Japanese PALV strains in the other genome segments. Our data suggest that the Japanese MARV strains were reassortant viruses between Asian and Australian PALVs. In addition to the WGS, we developed a real-time reverse-transcription polymerase chain reaction assay that can broadly detect PALV and specifically detect CHUV and DAGV, utilizing the data obtained by the WGS in this study. We detected the DAGV gene in bovine stillborn fetuses and congenitally abnormal calves in 2019 using the newly developed assay. To our knowledge, this is the first report of isolation of MARV outside of Australia and the first report of detection of PALV in bovine fetuses or calves with congenital abnormality outside of Africa.

Streptococcus pneumoniae serotypes 8 and 22F causing invasive pneumococcal disease in the Czech Republic in 2014-2020: whole genome sequencing (WGS) analysis.

AIM: An analysis is presented of whole genome data of Streptococcus pneumoniae serotypes 8 and 22F isolated in the Czech Republic from invasive pneumococcal disease (IPD) in 2014-2020. New multivalent pneumococcal conjugate vaccines (PCVs) are effective against these serotypes. Recently, serotypes 8 and 22F have been among the leading causes of IPD in the Czech Republic. S. pneumoniae isolates from the Czech Republic were compared with those of the same serotypes recovered in other countries in the same period and available in the international database PubMLST. MATERIAL AND METHODS: Isolates from IPD of serotypes 8 (22 isolates) and 22F (21 isolates) recovered in the Czech Republic in 2014-2020 were subjected to whole genome sequencing (WGS). The genomes were analysed and compared using the international database PubMLST. RESULTS: Most of the studied Czech serotype 8 isolates belong to two main subpopulations. The first subpopulation, dominated by ST-53 isolates, is part of a highly abundant group of genetically close European and non-European isolates that are clearly separated on the phylogenetic network. The second subpopulation of Czech serotype 8 isolates (dominated by ST-404) is more genetically variable and forms a separate lineage on the global phylogenetic network, with no other European isolates. Czech isolates of serotype 22F are a homogeneous population with a clear predominance of ST-433, which belongs to a genetically close European population. CONCLUSION: The analysis of WGS data of IPD isolates of serotypes 8 and 22F provided a detailed insight into the genetic relationships between the Czech populations of these serotypes. It also allowed comparison of the Czech populations with the matched populations from other European and non-European countries. The obtained results add to the body of knowledge about the spread of genetic lineages causing IPD in the Czech Republic in the post-vaccination period and provide a basis for considering whether the use of the new multivalent PCVs in the Czech Republic would be beneficial.

Unraveling the Genomic Evolution of Dengue Virus Serotype 1: A Case Study from Yantai, China.

In August 2023, we identified a case of dengue fever in Yantai City, which was imported from Xishuangbanna, China. To investigate its evolutionary history and population dynamics, we utilized the metatranscriptomic method to obtain the virus' whole genome sequence. Together with 367 selected dengue virus whole genome sequences from the NCBI database, we constructed a time-scaled Maximum Clade Credibility (MCC) tree. We found that our sequence exhibited a high homology with a sequence of DENV1 (OR418422.1) uploaded by the Guangzhou Center for Disease Control and Prevention in 2023, with an estimated divergence time around 2019 (95% HPD: 2017-2023), coinciding with the emergence of SARS-CoV-2. The DENV strain obtained in this study belongs to genotype I of DENV1. Its ancestors experienced a global epidemic around 2005 (95% HPD: 2002-2010), and its progeny strains have spread extensively in Southeast Asia and China since around 2007 (95% HPD: 2006-2011). The Bayesian skyline plot indicates that the current population of DENV1 has not been affected by SARS-CoV-2 and is expected to maintain stable transmission. Hence, it is imperative to track and monitor its epidemiological trends and genomic variations to prevent potential large-scale outbreaks in the post-SARS-CoV-2 era.

Development of recombinant proteins for vaccine candidates against serotypes O and A of Foot-and-Mouth Disease virus in Bangladesh.

Frequent vaccine failure leading to recurrent outbreaks of Foot-and-Mouth Disease (FMD) in livestock populations necessitates the development of a customizable vaccine platform comprising potential antigenic determinants of circulating lineages of FMD viruses. Artificially designed, chimaeric protein-based recombinant vaccines are novel approaches to combat the phylogenetically diverse FMD Virus (FMDV) strains. Among seven recognized serotypes, only serotypes O and A are dominantly circulating in Bangladesh and neighbouring countries of Asia, where transboundary transmission, recurrent outbreaks and emergence of novel lineages of FMDV are highly prevalent. The objective of this study was to develop multi-epitope recombinant proteins, procuring immunogenicity against circulating diverse genotypes of FMDV serotypes O and A. Two chimaeric proteins, named B1 (41.0 kDa) and B3 (39.3 kDa), have been designed to incorporate potential B-cell and T-cell epitopes selected from multiple FMDV strains, including previously reported and newly emerged sub-lineages. After expression, characterization and immunization of guinea pigs with a considerable antigen load of B1 and B3 followed by serological assays revealed the significant protective immunogenicity, developed from the higher (100 µg) doses of both antigens, against most of the currently prevalent serotype O and A strains of FMDV. The efficient expression, antigenic stability, and multivalent immunogenic potency of the chimaeric proteins strongly indicate their credibility as novel vaccine candidates for existing serotypes O and A of FMDV in Bangladesh and surrounding territories.

Prevalence, Clinical Severity, and Serotype Distribution of Pneumococcal Pneumonia Among Adults Hospitalized With Community-Acquired Pneumonia in Tennessee and Georgia, 2018-2022.

INTRODUCTION: Understanding the pneumococcal serotypes causing community-acquired pneumonia (CAP) is essential for evaluating the impact of pneumococcal vaccines. METHODS: We conducted a prospective surveillance study of adults aged ≥18 years hospitalized with CAP at 3 hospitals in Tennessee and Georgia between 1 September 2018 and 31 October 2022. We assessed for pneumococcal etiology with cultures, the BinaxNOW urinary antigen detection test, and serotype-specific urinary antigen detection assays that detect 30 pneumococcal serotypes contained in the investigational pneumococcal conjugate vaccine V116, as well as licensed vaccines PCV15 and PCV20 (except serotype 15B). The distribution of pneumococcal serotypes was calculated based on serotype-specific urinary antigen detection results. RESULTS: Among 2917 hospitalized adults enrolled with CAP, 352 (12.1%) patients had Streptococcus pneumoniae detected, including 51 (1.7%) patients with invasive pneumococcal pneumonia. The 8 most commonly detected serotypes were: 3, 22F, 19A, 35B, 9N, 19F, 23A, and 11A. Among 2917 adults with CAP, 272 (9.3%) had a serotype detected that is contained in V116, compared to 196 (6.7%) patients with a serotype contained in PCV20 (P < .001), and 168 (5.8%) patients with a serotype contained in PCV15 (P < .001). A serotype contained in V116 but not PCV15 or PCV20 was detected in 120 (4.1%) patients, representing 38.0% of serotype detections. CONCLUSIONS: Approximately 12% of adults hospitalized with CAP had S. pneumoniae detected, and approximately one-third of the detected pneumococcal serotypes were not contained in PCV15 or PCV20. Development of new pneumococcal vaccines with expanded serotype coverage has the potential to prevent a substantial burden of disease.

Contamination of Streptococcus suis and S. suis Serotype 2 in Raw Pork and Edible Pig Organs: A Public Health Concern in Chiang Mai, Thailand.

Streptococcus suis is one of the most important zoonotic pathogens causing serious diseases in both pigs and humans, especially serotype 2. In northern Thailand, there is a notable prevalence of S. suis infection in humans and transmission has occurred mainly through the consumption of raw pork products. Despite the continued practice of consuming raw pork in this region, limited data exist regarding S. suis contamination in such products. Therefore, this study aimed to assess the prevalence of S. suis and S. suis serotype 2 in retail raw pork meat and edible pig organs sold in Chiang Mai city, Thailand. A total of 200 samples, comprising raw pork meat and edible pig organs, were collected from nine fresh markets in Chiang Mai city between May and July 2023. Samples were prepared and cultured in Todd-Hewitt broth. Bacterial DNA was extracted and tested for any serotypes of S. suis and serotype 2 using loop-mediated isothermal amplification (LAMP) techniques. The study revealed contaminations of S. suis and serotype 2 at rates of 84% and 34%, respectively, with a higher prevalence observed in pig organs compared to raw pork. Both S. suis and serotype 2 were detected across all nine fresh markets investigated. The prevalence of S. suis remained consistently high throughout the study period, whereas serotype 2 showed peaks in May and July. These high rates of contamination indicate that people who consume or work in close contact with raw pork or edible pig organs are at a high risk of S. suis infection. Urgent implementation and maintenance of food safety campaigns and public health interventions are crucial for disease prevention and control.

Differences in the pathogenicity and molecular characteristics of fowl adenovirus serotype 4 epidemic strains in Guangxi Province, southern China.

Starting in 2015, the widespread prevalence of hydropericardium-hepatitis syndrome (HHS) has led to considerable financial losses within China's poultry farming industry. In this study, pathogenicity assessments, whole-genome sequencing, and analyses were conducted on 10 new isolates of the novel genotype FAdV-4 during a HHS outbreak in Guangxi Province, China, from 2019 to 2020. The results indicated that strains GX2019-010 to GX2019-013 and GX2019-015 to GX2019-018 were highly virulent, while strain GX2020-019 exhibited moderate virulence. Strain GX2019-014 was characterized as a wild-type strain with low virulence, displaying no pathogenic effects when 0.5 mL containing 106 TCID50 virus was inoculated into the muscle of specific pathogen-free (SPF) chickens at 4 weeks of age, while 107 TCID50 and 108 TCID50 resulted in mortality rates of 80 and 100%, respectively. The whole genomes of strains GX2019-010 to GX2019-013, GX2019-015 to GX2019-018, and GX2020-019 showed high homology with other Chinese newly emerging highly pathogenic FAdV-4 strains, whereas GX2019-014 was closer to nonmutant strains and shared the same residues with known nonpathogenic strains (B1-7, KR5, and ON1) at positions 219AA and 380AA of the Fiber-2 protein. Our work enriches the research on prevalent strains of FAdV-4 in China, expands the knowledge on the virulence diversity of the novel genotype FAdV-4, and provides valuable reference material for further investigations into the key virulence-associated genetic loci of FAdV-4.

Multiplex PCR-based genotyping of Salmonella Enteritidis and Salmonella Typhimurium from food sources and assessment of their antimicrobial resistance profiles in Egypt.

BACKGROUND: Salmonellosis is a widespread zoonotic disease that poses a significant threat to livestock and public health. This study aimed to serotype 20 Salmonella isolates obtained from sixty retail chicken meats, assess Salmonella contamination from eggs, and evaluate antibiotic resistance profiles. METHODS AND RESULTS: Twenty eggs were randomly collected in the new Borg El Arab market. Bacterial isolation was carried out utilizing both traditional culture, biochemical, and PCR methods. Among the twenty eggs analyzed, three (15%) tested positive for Salmonella, while the remaining seventeen (85%) were confirmed as negative. Genotyping through multiplex PCR revealed the presence of two S. Enteritidis and other serovar, with the use of three specific gene sets: a random sequence for Salmonella spp., sdfI gene for S. Enteritidis, and flagellin (fliC gene) for S. Typhimurium. Out of the 20 isolates obtained from chicken meat, five (25%) were identified as S. Typhimurium, and three (15%) were classified as S. Enteritidis. All isolates sourced from chicken meat exhibited resistance to Rifampicin and Amoxicillin, with 90% displaying sensitivity to cefotaxime, gemifloxacin, and Erythromycin. Importantly, S. Blegdam, identified via serological methods, displayed resistance to all tested antibiotics. For the three isolates obtained from eggs, 66.6% showed sensitivity to cefotaxime, erythromycin, cefuraxime, and cefaclor, while displaying complete resistance (100%) to Amoxicillin, rifampicin, clarithromycin, and cefadroxil. Notably, one serovar exhibited absolute resistance to all tested drugs. CONCLUSION: Stakeholders must implement strict control measures and rationalize antibiotic use in veterinary and human medicine due to the rise of antibiotic-resistant strains.

Investigation of different cold adaptation abilities in Salmonella enterica serotype Typhimurium strains using extracellular metabolomic approach.

This study explored the extracellular metabolomic responses of three different Salmonella enterica serotype Typhimurium (S. Typhimurium) strains-ATCC 13311 (STy1), NCCP 16964 (STy4), and NCCP 16958 (STy8)-cultured at refrigeration temperatures. The objective was to identify the survival mechanisms of S. Typhimurium under cold stress by analyzing variations in their metabolomic profiles. Qualitative and quantitative assessments identified significant metabolite alterations on day 6, marking a critical inflection point. Key metabolites such as trehalose, proline, glycerol, and tryptophan were notably upregulated in response to cold stress. Through multivariate analyses, the strains were distinguished using three metabolites-4-aminobutyrate, ethanol, and uridine-as potential biomarkers, underscoring distinct metabolic responses to refrigeration. Specifically, STy1 exhibited unique adaptive capabilities through enhanced metabolism of betaine and 4-aminobutyrate. These findings highlight the variability in adaptive strategies among S. Typhimurium strains, suggesting that certain strains may possess more robust metabolic pathways for enhancing survival in refrigerated conditions.

Enrichment culture evaluation and characterization of Streptococcus agalactiae among pregnant women in Japan.

Introduction. Maternal screening tests and prophylactic antibiotics are important to prevent neonatal and infant group B streptococcal (GBS) infections.Hypothesis/Gap Statement. The performance of enrichment broth media for GBS screening that are available in Japan is unclear. Whole-genome data of GBS isolates from pregnant women in Japan is lacking.Aim. The aim of this study was to compare the protocol performance of six enrichment broths and two subculture agar plates, which were all available in Japan, for GBS detection. In addition, we showed whole-genome data of GBS isolates from pregnant women in Japan.Methodology. We collected 133 vaginal-rectal swabs from pregnant women visiting clinics and hospitals in Nagasaki Prefecture, Japan, and compared the protocol performance of 6 enrichment broths and 2 subculture agar plates. All GBS isolates collected in this study were subjected to whole-genome sequencing analysis.Results. We obtained 133 vaginal-rectal swabs from pregnant women at 35-37 weeks of gestation from 8 private clinics and 2 local municipal hospitals within Nagasaki Prefecture, Japan. The detection rate of the protocol involving the six enrichment broths and subsequent subcultures varied between 95.5 and 100 %, depending on the specific choice of enrichment broth. The GBS carriage rate among pregnant women in this region was 18.8 %. All 25 isolates derived from the swabs were susceptible to penicillin, whereas 48 and 36 % of the isolates demonstrated resistance to erythromycin and clindamycin, respectively. The distribution of serotypes was highly diverse, encompassing seven distinct serotypes among the isolates, with the predominant serotype being serotype V (n = 8). Serotype V isolates displayed a tendency towards increased resistance to erythromycin and clindamycin, with all resistant isolates containing the ermB gene.Conclusion. There was no difference in performance among the culture protocols evaluated in this study. GBS strains isolated from pregnant women appeared to have greater genomic diversity than GBS strains detected in neonates/infants with invasive GBS infections. To confirm this result, further studies with larger sample sizes are needed.