Field assessment of potential exposure of dogs to leptospirosis by measuring antibody titers in dogs: a multisite study in five geographic regions of the United States.

Leptospirosis vaccine for dogs in the United States is considered a lifestyle or non-core vaccine, making individual veterinary practitioners responsible for determining if vaccination is necessary for their patients. Veterinary professionals often base their vaccination decisions on local rates of clinical cases. However, even subclinical leptospirosis infections have zoonotic potential. The microscopic agglutination test (MAT) is effective for screening unvaccinated animals, but previous vaccination can lead to inconsistent results and variable MAT titers over time. This prospective research survey evaluated if local experience was sufficient to justify selective vaccination for leptospirosis. MAT analyses were performed on sera collected from well-cared-for, unvaccinated dogs residing in five different geographies across the United States: South-Central (East Texas), New England, the Mid-Atlantic (North Carolina and Virginia), Midwest (Wisconsin/northern Illinois), and Southwest (southern California). Thirty-eight clinics participated, submitting a total of 1345 qualified samples from unvaccinated dogs over 1 year of age. 11.6% of these unvaccinated dogs had MAT titers for one or more serogroups of Leptospira. While seropositivity does not necessarily indicate that disease will result or that a specific serovar is involved, these MAT-positive cases do indicate that the potential for exposure exists and clinical signs or a carrier-state could result from infection. These survey results would indicate that a more aggressive vaccination protocol for leptospirosis should be considered.

Exploring of spectrum beta lactamase producing multidrug-resistant Salmonella enterica serovars in goat meat markets of Bangladesh.

The emergence of Salmonella enterica serovars that produce extended-spectrum beta-lactamase and exhibit multi-drug resistance (MDR) poses a substantial global threat, contributing to widespread foodborne illnesses and presenting an alarming issue for public health. This study specifically concentrated on the isolation and identification of ESBL-resistant genes (bla TEM, bla SHV, bla CTX-M1, bla CTX-M2, bla CTX-M9, MultiCase ACC, MultiCase MOX, MultiCase DHA, bla OXA) and the antibiogram profiling of Salmonella enterica serovars found in goat meat samples procured from retail outlets in Bangladesh. During the research in the Sylhet district of Bangladesh, researchers gathered a total of 210 samples of goat meat from 13 different Upazilas. Primarily, cultural and biochemical methods were used for isolation of bacteria from the selected samples. Salmonella enterica serovars Typhimurium and Enteritidis, along with three ESBL-resistant genes, were identified through polymerase chain reactions (PCRs). The disk diffusion test was used to determine antimicrobial susceptibilities. Out of 210 samples analysed, Salmonella spp. was detected in 18.10 % (38 out of 210), with S. Enteritidis and S. Typhimurium found in 9.05 % (19 out of 210) and 5.24 % (11 out of 210) of the samples, respectively. A total of 72.73 % (8/11) of S. Enteritidis and 100 % (19/19) of S. Typhimurium isolates were positive by Multidrug-resistant patterns. The positive outcomes were found of S. Typhimurium tested 63.16 % (12 out of 19) for the bla TEM gene and 21.05 % (4/19) for the bla SHV, gene. The study proposes that the retail goat meat market channel could be a prominent transmission way of ESBL-producing MDR Salmonella enterica serovars, representing a significant public health hazard.

Application of pulsed-field gel electrophoresis for molecular identification of pathogenic Leptospira species in Iran: a rapid and reliable method.

Background and Objectives: Leptospirosis is a zoonotic disease caused by pathogenic Leptospira serovars. The genus Leptospira cannot differentiated by conventional techniques. However, identity determination of pathogenic serovar is precious of public health problems and epidemiological studies. Pulsed-field gel electrophoresis facilitates rapid identification of Leptospires to the serovar levels. Materials and Methods: In this study, we employed PFGE to evaluate 28 Leptospira isolates, with animal, human and environmental origin, obtained from Razi Vaccine and Serum Research Institute of Karaj, Iran. PFGE patterns of 28 Leptospira serovars were generated using the Not I restriction enzyme in comparison with the lambda ladder. Results: Out of 28 serovars evaluated, we identified 22 different pulsed types, designated P1-P22. Out of 22 pulse groups, 3 were found to be a common type, but others were a single Type. Groups consisting of the common type were P3, P9, P14, and P16. The results showed that the discriminatory index of PFGE by Not I enzyme was 0.99, demonstrating heterogeneous differentiation among serovar members. Conclusion: The PFGE methodology used in this study showed excellent interlaboratory report usability, rapid, reliable, enabling standardization and data sharing between laboratories.

Colistin-, cefepime-, and levofloxacin-resistant Salmonella enterica serovars isolated from Egyptian chicken carcasses.

OBJECTIVES: The emergence of multidrug-resistant (MDR) Salmonella strains, especially resistant ones toward critically important antimicrobial classes such as fluoroquinolones and third- and fourth-generation cephalosporins, is a growing public health concern. The current study, therefore, aimed to determine the prevalence, and existence of virulence genes (invA, stn, and spvC genes), antimicrobial resistance profiles, and the presence of ß-lactamase resistance genes (blaOXA, blaCTX-M1, blaSHV, and blaTEM) in Salmonella strains isolated from native chicken carcasses in Egypt marketed in Mansoura, Egypt, as well as spotlight the risk of isolated MDR, colistin-, cefepime-, and levofloxacin-resistant Salmonella enterica serovars to public health. METHODS: One hundred fifty freshly dressed native chicken carcasses were collected from different poultry shops in Mansoura City, Egypt between July 2022 and November 2022. Salmonella isolation was performed using standard bacteriological techniques, including pre-enrichment in buffered peptone water (BPW), selective enrichment in Rappaport Vassiliadis broth (RVS), and cultivating on the surface of xylose-lysine-desoxycholate (XLD) agar. All suspected Salmonella colonies were subjected to biochemical tests, serological identification using slide agglutination test, and Polymerase Chain Reaction (PCR) targeting the invasion A gene (invA; Salmonella marker gene). Afterward, all molecularly verified isolates were screened for the presence of virulence genes (stn and spvC). The antimicrobial susceptibility testing for isolated Salmonella strains towards the 16 antimicrobial agents tested was analyzed by Kirby-Bauer disc diffusion method, except for colistin, in which the minimum inhibition concentration (MIC) was determined by broth microdilution technique. Furthermore, 82 cefotaxime-resistant Salmonella isolates were tested using multiplex PCR targeting the ß-lactamase resistance genes, including blaOXA, blaCTX-M1, blaSHV, and blaTEM genes. RESULTS: Salmonella enterica species were molecularly confirmed via the invA Salmonella marker gene in 18% (27/150) of the freshly dressed native chicken carcasses. Twelve Salmonella serotypes were identified among 129 confirmed Salmonella isolates with the most predominant serotypes were S. Kentucky, S. Enteritidis, S. Typhimurium, and S. Molade with an incidence of 19.4% (25/129), 17.1% (22/129), 17.1% (22/129), and 10.9% (14/129), respectively. All the identified Salmonella isolates (n = 129) were positive for both invA and stn genes, while only 31.8% (41/129) of isolates were positive for the spvC gene. One hundred twenty-one (93.8%) of the 129 Salmonella-verified isolates were resistant to at least three antibiotics. Interestingly, 3.9%, 14.7%, and 75.2% of isolates were categorized into pan-drug-resistant, extensively drug-resistant, and multidrug-resistant, respectively. The average MAR index for the 129 isolates tested was 0.505. Exactly, 82.2%, 82.2%, 63.6%, 51.9%, 50.4%, 48.8%, 11.6%, and 10.1% of isolated Salmonella strains were resistant to cefepime, colistin, cefotaxime, ceftazidime/clavulanic acid, levofloxacin, ciprofloxacin, azithromycin, and meropenem, respectively. Thirty-one out (37.8%) of the 82 cefotaxime-resistant Salmonella isolates were ß-lactamase producers with the blaTEM as the most predominant ß-lactamase resistance gene, followed by blaCTX-M1 and blaOXA genes, which were detected in 21, 16, and 14 isolates respectively). CONCLUSION: The high prevalence of MDR-, colistin-, cefepime-, and levofloxacin-resistant Salmonella serovars among Salmonella isolates from native chicken is alarming as these antimicrobials are critically important in treating severe salmonellosis cases and boost the urgent need for controlling antibiotic usage in veterinary and human medicine to protect public health.

Molecular Characteristics of Salmonella Spp. Responsible for Bloodstream Infections in a Tertiary Hospital in Nanjing, China, 2019-2021.

Objective: To investigate the clinical and molecular characteristics of Salmonella spp. causing bloodstream infections (BSIs) in our hospital. Methods: We studied 22 clinical Salmonella isolates from BSIs and 16 from non-BSIs, performing antimicrobial susceptibility testing (AST) and whole genome sequencing (WGS). The analysis included serovars, antibiotic resistance genes (ARGs), virulence factors (VFs), sequence types (STs), plasmid replicons, and genetic relationships. We also assessed pathogenicity of the isolates causing BSIs through growth, biofilm formation, and anti-serum killing assays. Results: WGS analysis identified 13 Salmonella serovars, with four responsible for BSIs. S. Enteritidis was the most prevalent serovar, involved in 19 (50.0%) cases. BSIs were caused by 17S. Enteritidis, two S. Typhimurium, two S. Munster and one S. Diguel. Of the 38 isolates, 27 (71.1%) exhibited high resistance to ampicillin, and 24 (63.2%) to ampicillin/sulbactam. Thirty-six types of ARGs were identified, with blaTEM-1B (n = 25, 65.8%) being the most frequent. Ten plasmid replicons were found; the combination of IncFIB(S)-IncFII(S)-IncX1 was the most common in S. Enteritidis (94.7%). Fifteen STs were identified, among which ST11 was the most prevalent and clonally disseminated, primarily responsible for BSIs. A total of 333 different VFs were detected, 177 of which were common across all strains. No significant differences were observed between the BSI and non-BSI isolates in terms of resistance rates, ARGs, plasmid replicons, and VFs, except for seven VFs. No strong pathogenicity was observed in the BSI-causing isolates. Conclusion: BSIs were predominantly caused by clonally disseminated S. Enteritidis ST11, the majority of which carried multiple ARGs, VFs and plasmid replicons. This study provides the first data on clonally disseminated S. Enteritidis ST11 causing BSIs, highlighting the urgent need for enhanced infection control measures.

Antimicrobial Resistance of Listeria monocytogenes Strains Isolated in Food and Food-Processing Environments in Italy.

Listeria monocytogenes, along with various other pathogenic bacteria, may show resistance against a broad spectrum of antibiotics. Evaluating the extent of resistance in harmful microorganisms like Listeria monocytogenes holds significant importance in crafting novel therapeutic strategies to mitigate or combat the rise of infections stemming from antibiotic-resistant bacteria. The present work aims to investigate the occurrence of antimicrobial resistance among Listeria monocytogenes strains in meat products (n = 173), seafood (n = 54), dairy products (n = 19), sauces (n = 2), confectionary products (n = 1), ready-to-eat rice dishes (n = 1), and food-processing environments (n = 19). A total of 269 Listeria monocytogenes strains belonging to eight different serovars were tested against 10 antimicrobials. In the classes of antibiotics, most of the strains were resistant antibiotics belonging to the family of ß-lactams (92.94%). High proportions of L. monocytogenes isolates were resistant to oxacillin (88.48%), followed by fosfomycin (85.87%) and flumenique (78.44%). The lowest level of resistance was observed against gentamycin (1.49%). A total of 235 strains (n = 87.36%) showed a profile of multidrug resistance. In conclusion, a high occurrence of resistant and multidrug-resistant strains of Listeria monocytogenes was observed among the examined serotypes isolated from different food sources. This understanding enables the adoption of suitable measures to avert contamination and the spread of resistant bacteria via food.

Detection of Salmonella Pathogenicity Islands and Antimicrobial-Resistant Genes in Salmonella enterica Serovars Enteritidis and Typhimurium Isolated from Broiler Chickens.

Rapid growth in commercial poultry production is one of the major sources of Salmonella infections that leads to human salmonellosis. The two main Salmonella enterica serovars associated with human salmonellosis are enteritidis and typhimurium. The aim of this study was to determine the prevalence of S. enterica serovars Enteritidis and S. Typhimurium as well as their Salmonella pathogenicity islands (SPI) and antibiotic resistance profiles in broiler chicken feces from slaughterhouses. A total of 480 fecal samples from broiler chickens that were grouped into 96 pooled samples were identified to have Salmonella spp. using the invA gene, whilst the Spy and sdfI genes were used to screen for the presence of S. Enteritidis and S. Typhimurium serovars, respectively, by polymerase chain reaction (PCR) assays. The isolates were also screened for the presence of Salmonella pathogenicity islands (SPIs) using PCR. The disc diffusion assay was performed to determine the antibiotic resistance profiles of the isolates. A total of 36 isolates were confirmed as Salmonella spp. through amplification of the invA gene. Out of 36 confirmed Salmonella spp. a total of 22 isolates were classified as S. Enteritidis (n = 8) and were S. Typhimurium (n = 14) serovars. All (n = 22) S. Enteritidis and S. Typhimurium isolates possessed the hilA (SPI-1), ssrB (SPI-2) and pagC (SPI-11) pathogenicity islands genes. Amongst these serovars, 50% of the isolates (n = 11/22) were resistant to tetracycline and nalidixic acid. Only 22% of the isolates, S. Typhimurium (13.6%) and S. Enteritidis (9.1%) demonstrated resistance against three or more antibiotic classes. The most detected antibiotic resistance genes were tet(K), mcr-1, sulI and strA with 13 (59.1%), 9 (40.9%), 9 (40.9%) and 7 (31.8%), respectively. The findings of this study revealed that S. Typhimurium is the most prevalent serotype detected in chicken feces. To reduce the risk to human health posed by salmonellosis, a stringent public health and food safety policy is required.

AMR mechanisms in L. interrogans serovars: a comprehensive study.

Antimicrobial resistance (AMR) is one of the global health challenges of the 21st century. Data regarding AMR mechanisms in Leptospira interrogans, the causative agents of leptospirosis, have been relatively limited. Therefore, our study aimed to identify resistance genes and explore potential resistance mechanisms specific to particular serovars. We conducted a comprehensive analysis of 98 Leptospira strains, representing 10 common serovars, using whole-genome sequencing (WGS) FASTA files. Employing the PATRIC tool from the Bacterial and Viral Bioinformatics Resource Center (BV-BRC), we scrutinized the genomes for AMR genes. Our investigation revealed 32 genes associated with AMR, with 20 key genes consistently prevalent across most strains. Notably, we identified unique efflux pump systems in serovar Pomona, indicating distinctive resistance mechanisms in this serovar. In summary, our findings shed light on the genetic landscape of AMR in Leptospira, uncovering both common and serovar-specific resistance elements. The presence of unique efflux pump systems in serovar Pomona introduces a novel dimension to our understanding of resistance mechanisms. These insights underscore the importance of tailored intervention strategies and collaborative efforts between human and veterinary healthcare professionals, as well as environmental scientists, to address the complex dynamics of leptospirosis and its implications for antibiotic resistance.

Improved Antibody Detection for Canine Leptospirosis: ELISAs Modified Using Local Leptospiral Serovar Isolates from Asymptomatic Dogs.

Leptospirosis is a zoonotic disease of significant concern for human and animal health, with domestic animals, including dogs, acting as reservoirs for human infection. Serology is widely used for leptospirosis diagnosis, even though the standard microscopic agglutination test (MAT) using a panel of serovars lacks specificity and can lead to detection limitations in certain regions. In this study, we aimed to develop an antibody detection tool for dogs using an indirect enzyme-linked immunosorbent assay (ELISA) with a set of local serovar isolates, including Paidjan, Dadas, and Mini, to enhance the accuracy of leptospirosis surveillance in our region. The specificity and sensitivity of various antigen preparations, namely leptospiral whole-cell protein (WCP), total membrane protein (TMP), and outer membrane protein (OMP), were assessed using sera from infected and non-infected dogs, as well as negative puppy sera. Leptospirosis diagnosis was supported using a genus-specific nested polymerase chain reaction test on all collected sera. Protein preparations were validated using SDS-PAGE and Western blotting analysis. In the results, the standard MAT failed to detect antibodies in any of the dogs confirmed as being infected using PCR and isolation, highlighting its limitations. In contrast, the OMP-based ELISAs using local isolates of Leptospira serovars gave positive results with sera from all infected dogs, and negative results with sera from all dogs from non-endemic areas. IgG titres of infected and unvaccinated dogs from endemically affected areas were significantly higher than those in non-endemic regions. Using the OMP-based IgG/ELISAs with the local serovar Dadas resulted in higher specificity and lower sensitivity than when using the WCP- and TMP-based IgG/ELISAs. Agreement analysis revealed fair and moderate concordance between OMP-based IgG/ELISAs and PCR results, whereas slight and fair agreement was observed between OMP-based ELISAs and the MAT. Overall, the modified OMP-based IgG/ELISAs, utilising relevant local serovar isolates from dogs, demonstrated improved accuracy in detecting leptospirosis in the study area, overcoming the limitations of the MAT. This study highlights the importance of identifying and incorporating these local circulating serovar isolates into serological techniques for leptospirosis diagnosis and surveillance.

Diverse Prophage Elements of Salmonella enterica Serovars Show Potential Roles in Bacterial Pathogenicity.

Nontyphoidal salmonellosis is an important foodborne and zoonotic infection that causes significant global public health concern. Diverse serovars are multidrug-resistant and encode several virulence indicators; however, little is known on the role prophages play in driving these traits. Here, we extracted prophages from seventy-five Salmonella genomes which represent the fifteen important serovars in the United Kingdom. We analyzed the intact prophages for the presence of virulence genes and established their genomic relationships. We identified 615 prophages from the Salmonella strains, from which 195 prophages are intact, 332 are incomplete, while 88 are questionable. The average prophage carriage was found to be 'extreme' in S. Heidelberg, S. Inverness, and S. Newport (10.2-11.6 prophages/strain), 'high' in S. Infantis, S. Stanley, S. Typhimurium, and S. Virchow (8.2-9.0 prophages/strain), 'moderate' in S. Agona, S. Braenderup, S. Bovismorbificans, S. Choleraesuis, S. Dublin, and S. Java (6.0-7.8 prophages/strain), and 'low' in S. Javiana and S. Enteritidis (5.8 prophages/strain). Cumulatively, 61 virulence genes (1500 gene copies) were detected from representative intact prophages and linked to Salmonella delivery/secretion system (42.62%), adherence (32.7%), magnesium uptake (3.88%), regulation (5%), stress/survival (1.6%), toxins (10%), and antivirulence (1.6%). Diverse clusters were formed among the intact prophages and with bacteriophages of other enterobacteria, suggesting different lineages and associations. Our work provides a strong body of data to support the contributions diverse prophages make to the pathogenicity of Salmonella, including thirteen previously unexplored serovars.

Levels of Cytokines in Leptospirosis Patients with Different Serovars and rfb Locus.

Leptospirosis has a wide spectrum of clinical manifestations ranging from mild to severe disease. The cytokine response is considered one of the key drivers for this varying manifestation. The different cytokine response observed in patients with leptospirosis could be due to the variation of infecting serovars. Since the rfb locus codes for the lipopolysaccharide synthesis of the bacterial cell wall, which also determines the serovar, this locus may play a role in driving a specific cytokine response in the host. We investigated 12 commonly used cytokine profiles in serum samples of culture, microscopic agglutination test (MAT), or polymerase chain reaction (PCR)-positive patients with leptospirosis. The sequences of the rfb locus in culture-positive samples were generated from whole genome sequencing and serovar status was drawn from original data published. Isolated cultures were subjected to whole genome sequencing using the PacBio RS II system, and the resulting data were used to determine the species. The recovered genomic data were annotated with the Rapid Annotation using Subsystem Technology (RAST) subsystem, and the rfb locus was extracted. The cytokine analysis was carried out using the Qiagen human ELISA kit. Eighteen samples were found to be positive by culture, while the other 7 samples were positive by PCR or MAT. Infections from Leptospira interrogans serovar Autumnalis (5), Pyrogens (3), Icterohaemorrhagiae (1) Leptospira borgpetersenii (all 7 samples clustered in same clonal group with serovar status not determined), Leptospira weilii (1 with serovar status not determined), and Leptospira kirschneri serovar Grippotyphosa (1) were included in the analysis. Three patients [infected with Leptospira interrogansserovar Autumnalis (2) and Pyrogens (1)] and 2 MAT-positive patients (highest titer against serovar Bratislava of L.interrognas) were reported to have severe clinical manifestations, while the rest had mild to moderate symptoms. Although the serum cytokine concentration of patients with severe clinical manifestation was comparatively higher, a statistically significant difference was observed only for interleukin (IL)-1ß (P < 0.05). IL-10/tumor necrosis factor-alpha (TNF-α) ratio was high in patients with severe complications. In general, patients infected with L. interrogans showed higher concentration of cytokines compared to L. borgpetersenii.

Salmonella serovars trend in poultry Malaysia from 2011 to 2020.

Data and geographical trend of Salmonella serovars infecting poultry in Malaysia is limited. In this study, the trend of Salmonella serovars infection was presented for the past ten years from 2011 to 2020 and the predominant serovars were mapped based on geographical distribution. Analysis of passive surveillance data demonstrated a shift of Salmonella serovars that infected poultry in Malaysia. The Salmonella serovars varied within ten years of registered cases with the Veterinary Research Institute, Ipoh, Malaysia involving samples from live and dead birds. Total number of cases found from the year 2011 to 2020 were 391 cases, involving 73 Salmonella serovars with an additional one group of unclassified serovars known as Salmonella spp. Further analysis revealed that eight serovars were found predominant throughout the ten-year period. These included S. Albany, S. Braenderup, S. Brancaster, S. Corvallis, S. Enteritidis, S. Kentucky, S. Typhimurium and S. Weltevreden. Salmonella spp. (Salmonella that is incapable to be identified based on serotyping) were also one of the major groups observed throughout the years. This study could help the authorities to improvise policies for better disease control programs through the establishment of diagnostic tools for rapid Salmonella screening in poultry.

Occurrence, genetic diversity and resistance profiles of Salmonella enterica from Brazilian sausages collected at production facilities.

This study aimed to investigate the occurrence and the genetic diversity of Salmonella enterica subsp. enterica in sausages from Southern Brazil, evaluate virulence genes and determine the phenotypic and genotypic basis of antimicrobial and sanitizer resistance. Salmonella was detected in sausage samples with an overall prevalence of 5.5%. The prevalent serovars were S. Infantis and S. Rissen. Pulsed-field gel electrophoresis (PFGE) analysis yielded nine distinct PFGE profiles, and some of them were recurrently recovered in the same establishment on different dates. Among tested isolates, 28.5% showed resistance to at least one antimicrobial agent and a multidrug-resistance (MDR) profile was observed in 21.4%. Resistance occurred most frequently to ampicillin, sulfonamide, trimethoprim/sulfamethoxazole, and trimethoprim. Regarding the genotypic antimicrobial resistance profile, S. Schwarzengrund carried tet(B), strA, strB, and sul2 genes. Benzalkonium chloride and chlorhexidine were more effective than peracetic acid and sodium hypochlorite, showing lower minimum inhibitory concentration values. Six Salmonella serovars were found, demonstrating a potential risk of salmonellosis associated with consuming this food. Salmonella carrying virulence genes, MDR profile, and tolerance to sanitizers is a public health concern and a challenge for the food industry, suggesting that new strategies should be developed to control this pathogen. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05809-w.

Poultry Processing Interventions Reduce Salmonella Serovar Complexity on Postchill Young Chicken Carcasses as Determined by Deep Serotyping.

Nearly 20% of salmonellosis cases are attributed to broilers, with renewed efforts to reduce Salmonella during broiler production and processing. A limitation to Salmonella culture is that often a single colony is picked for characterization, favoring isolation of the most abundant serovar found in a sample, while low abundance serovars can remain undetected. We used a deep serotyping approach, CRISPR-SeroSeq (serotyping by sequencing the clustered regularly interspaced palindromic repeats), to assess Salmonella serovar complexity during broiler processing and to determine the impact of antimicrobial interventions upon serovar population dynamics. Paired hot rehang and postchill young chicken carcasses were collected from establishments across the United States from August to November 2022. CRISPR-SeroSeq was performed on Salmonella culture-positive hot rehang (n = 153) and postchill (n = 38) samples, including 31 paired hot rehang and postchill samples. Multiple serovars were detected in 48.4% (74/153) and 7.9% (3/38) of hot rehang and postchill samples, respectively. On average, hot rehang carcasses contained 1.6 serovars, compared to 1.1 serovars at postchill (Mann Whitney U, p = 0.00018). Nineteen serovars were identified with serovar Kentucky the most common at hot rehang (72.5%; 111/153) and postchill (73.7%; 28/38). Serovar Infantis prevalence was higher at hot rehang (39.9%; 61/153) than in postchill (7.9%; 3/38). At hot rehang, serovar Enteritidis was outnumbered by other serovars 81.3% (13/16) of the time but was always the single or most abundant serovar detected when it was present at postchill (n = 5). We observed 98.4% (188/191) concordance between traditional isolation with serotyping and CRISPR-SeroSeq. Deep serotyping was able to explain serovar discrepancies between paired hot rehang and postchill samples when only traditional isolation and serotyping methods were used. These data demonstrate that processing interventions are effective in reducing Salmonella serovar complexity.

Leptospirosis in Malaysia: current status, insights, and future prospects.

Among zoonotic infections, leptospirosis has a worldwide distribution and high prevalence in tropical regions. It has a broad clinical presentation from mild to severe, life-threatening infection. Leptospires, the etiological agent of leptospirosis, are found in varied ecological niches and animal species, providing a significant source of human infection. This review aims to provide the current status of leptospirosis in Malaysia and the direction for future studies. The literature search for this review was performed using PubMed, Web of Sciences, and Google Scholar databases. The incidence of leptospirosis in Malaysia from 2004 to 2020 varied; however, a large number of cases occurred during floods. Leptospira has been isolated from wild and domestic animals as well as from the environment; among them, several novel species have been identified. In Malaysia, leptospirosis infection and death were mostly associated with recreational and non-recreational water activities. Despite the endemicity of leptospirosis, the public's knowledge, attitude, and practice level are relatively low in this country. More studies are needed in Malaysia to explore the extent of leptospirosis in different settings and locations.

Salmonella Bloodstream Infections.

Salmonella is a major foodborne pathogen of both animals and humans. This bacterium is responsible for considerable morbidity and mortality world-wide. Different serovars of this genus cause diseases ranging from self-limiting gastroenteritis to a potentially fatal systemic disease known as enteric fever. Gastrointestinal infections with Salmonella are usually self-limiting and rarely require medical intervention. Bloodstream infections, on the other hand, are often fatal even with hospitalization. This review describes the routes and underlying mechanisms of the extraintestinal dissemination of Salmonella and the chronic infections that sometimes result. It includes information on the pathogenicity islands and individual virulence factors involved in systemic dissemination as well as a discussion of the host factors that mediate susceptibility. Also, the major outbreaks of invasive Salmonella disease in the tropics are described.

Practical Preventive Considerations for Reducing the Public Health Burden of Poultry-Related Salmonellosis.

With poultry products as one of the leading reservoirs for the pathogen, in a typical year in the United States, it is estimated that over one million individuals contract non-typhoidal Salmonella infections. Foodborne outbreaks associated with Salmonella infections in poultry, thus, continue to remain a significant risk to public health. Moreover, the further emergence of antimicrobial resistance among various serovars of Salmonella is an additional public health concern. Feeding-based strategies (such as use of prebiotics, probiotics, and/or phytobiotics as well as essential oils), non-feeding-based strategies (such as use of bacteriophages, vaccinations, and in ovo strategies), omics tools and surveillance for identifying antibiotic-resistance genes, post-harvest application of antimicrobials, and biosecurity measures at poultry facilities are practical interventions that could reduce the public health burden of salmonellosis and antibiotic resistance associated with poultry products. With the escalating consumption of poultry products around the globe, the fate, prevalence, and transmission of Salmonella in agricultural settings and various poultry-processing facilities are major public health challenges demanding integrated control measures throughout the food chain. Implementation of practical preventive measures discussed in the current study could appreciably reduce the public health burden of foodborne salmonellosis associated with poultry products.

Comparison of Phenotype Nutritional Profiles and Phosphate Metabolism Genes in Four Serovars of Salmonella enterica from Water Sources.

The surveillance of foods for Salmonella is hindered by bias in common enrichment media where serovars implicated in human illness are outgrown by less virulent serovars. We examined four Salmonella serovars, two common in human illness (Enteritidis and Typhimurium) and two that often dominate enrichments (Give and Kentucky), for factors that might influence culture bias. The four serovars had similar growth kinetics in Tryptic Soy Broth and Buffered Peptone Water. Phenotype microarray analysis with 950 chemical substrates to assess nutrient utilization and stress resistance revealed phenotype differences between serovars. Strains of S. Enteritidis had better utilization of plant-derived sugars such as xylose, mannitol, rhamnose, and fructose, while S. Typhimurium strains were able to metabolize tagatose. Strains of S. Kentucky used more compounds as phosphorus sources and grew better with inorganic phosphate as the sole phosphorus source. The sequences of nine genes involved in phosphate metabolism were compared, and there were differences between serovars in the catalytic ATP-binding domain of the histidine kinase phoR. Analysis of the predicted PhoR amino acid sequences from additional Salmonella genomes indicated a conservation of sequences each within the Typhimurium, Give, and Enteritidis serovars. However, three different PhoR versions were observed in S. Kentucky.

Virulence and Antimicrobial Resistance Profiling of Salmonella Serovars Recovered from Retail Poultry Offal in KwaZulu-Natal Province, South Africa.

As poultry organ meat is widely consumed, especially in low- and middle-income countries, there is reason to investigate it as a source of Salmonella infections in humans. Consequently, the aim of this study was to determine the prevalence, serotypes, virulence factors and antimicrobial resistance of Salmonella isolated from chicken offal from retail outlets in KwaZulu-Natal, South Africa. Samples (n = 446) were cultured for the detection of Salmonella using ISO 6579-1:2017. Presumptive Salmonella were confirmed using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry. Salmonella isolates were serotyped using the Kauffmann-White-Le Minor scheme and antimicrobial susceptibility was determined by the Kirby-Bauer disk diffusion technique. A conventional PCR was used for the detection of Salmonella invA, agfA, lpfA and sivH virulence genes. Of the 446 offal samples, 13 tested positive for Salmonella (2.91%; CI = 1.6-5). The serovars included S. Enteritidis (n = 3/13), S. Mbandaka (n = 1/13), S. Infantis (n = 3/13), S. Heidelberg (n = 5/13) and S. Typhimurium (n = 1/13). Antimicrobial resistance against amoxicillin, kanamycin, chloramphenicol and oxytetracycline was found only in S. Typhimurium and S. Mbandaka. All 13 Salmonella isolates harboured invA, agfA, lpfA and sivH virulence genes. The results show low Salmonella prevalence from chicken offal. However, most serovars are known zoonotic pathogens, and multi-drug resistance was observed in some isolates. Consequently, chicken offal products need to be treated with caution to avoid zoonotic Salmonella infections.

Prevalence and antimicrobial susceptibility profile of Salmonella isolated from food products in the region of Casablanca, Morocco.

INTRODUCTION: Salmonellosis is a foodborne bacterial disease responsible for food epidemics around the world. The objective of this study is to determine the prevalence and diversity of Salmonella serotypes in several food products isolated at the Casablanca Regional Analysis and Research Laboratory and to test their resistance to different antimicrobials. METHODOLOGY: The isolation and identification of Salmonella were performed according to Moroccan standard 08.0.116. All isolates were serotyped and were then tested for antibiotic resistance using the disk diffusion method. The Salmonella isolates were further analyzed by PCR to detect the presence of virulence genes invA. RESULTS: 20 different serotypes were identified from 80 strains isolated from 2015 to 2019, the most common of which are S. kentucky (26.3%) followed by S. muenster (10%), S. typhimurium (8.7%), S. menston (7.5%) and S. enteritidis (6.3%). Antimicrobial susceptibility testing revealed that 66.25% of isolates were resistant to at least one of the 14 antimicrobial agents tested. Bacterial resistance was most frequently observed for tetracycline with 46.25%, 45% to sulfonamide, 35% to nalidixic acid, 26, 25% to ampicillin, and 25% to ciprofloxacin. Salmonella serotypes S. montevideo, S. virchow, S. amsterdam, S. anatum, and S. bloomsbury were 100% susceptible to all antimicrobials tested. Examination of Salmonella for invA gene was positive for all the strains. CONCLUSIONS: The results of this study have shown that minced meat has a high level of Salmonella contamination, which can be considered one of the main potential sources of human salmonellosis in Morocco.