Prevalence of multidrug-resistant extended spectrum beta-lactamase-producing Salmonella strains in commercial raw chicken meat

The incidence of extended spectrum beta-lactamase (ESBL)-producing pathogens is worrisome because it confers multiple drug resistance (MDR). Considering their serious clinical significance, the study investigated the prevalence of MDR-ESBL-producing Salmonella strains isolated from raw chicken meat in Southern Nigeria. A total of 240 raw chicken meat were sampled and the recovered Salmonella strains were characterized for MDR and ESBL-genes using Kirby Bauer disc diffusion and molecular techniques. Of the 52 confirmed Salmonellaenterica serotypes, 67.31% (35/52) were Salmonella entericasubsp. entericaserovar Typhimurium, 32.68% (17/52) were Salmonella entericasubsp. entericaserovar Enteritidis, 78.85% (41/52) were ESBL-producer and 88.45% (46/52) multidrug resistant. Ampicillin (96.15%) and gentamycin (40.39%) were the most and least antibiotics. The most prevalent MDR-ESBL-genes were bla CTX-M (92.68%), followed by bla SHV genes (68.29%) and bla TEM(31.71%). This study showed that Salmonella serotypes with high ESBL-genes and MDR were prevalent in raw chicken meat vended in southern Nigerian markets. Bangladesh J. Sci. Ind. Res.56(4), 271-284, 2021

Prevalence and Serotype Diversity of Salmonella enterica in the Estonian Meat Production Chain in 2016–2020

Background: Salmonella enterica represents a considerable public concern worldwide, with farm animals often recognised as an important reservoir. This study gives an overview of the prevalence and serotype diversity of Salmonella over a 5-year period in the meat production chain in Estonia. Data on human salmonellosis over the same period are provided. Methods: Salmonella surveillance data from 2016 to 2020 were analysed. Results: The prevalence of Salmonella at the farm level was 27.7%, 3.3% and 0.1% for fattening pigs, cattle and poultry, respectively. S. Derby was the most prevalent serotype at the farm level for fattening pigs and S. Dublin for cattle. The top three serotypes isolated at the slaughterhouse and meat cutting levels were S. Derby, monophasic S. Typhimurium and S. Typhimurium with proportions of 64.7%, 9.4% and 7.0%, respectively. These serotypes were the top five most common Salmonella serotypes responsible for human infections in Estonia. S. Enteritidis is the main cause (46.9%) of human salmonellosis cases in Estonia, but in recent years, Enteritidis has not been detected at the slaughterhouse or meat cutting level. Conclusion: In recent years, monophasic S. Typhimurium has become epidemiologically more important in Estonia, with the second-highest cause in human cases and third-highest among the most prevalent serotypes of Salmonella enterica in the meat chain.

Prevalence of Antibiotic Resistance in Salmonella Serotypes Concurrently Isolated from the Environment, Animals, and Humans in South Africa: A Systematic Review and Meta-Analysis

One of the main global concerns is the usage and spread of antibiotic resistant Salmonella serovars. The animals, humans, and environmental components interact and contribute to the rapid emergence and spread of antimicrobial resistance, directly or indirectly. Therefore, this study aimed to determine antibiotic resistance (AR) profiles of Salmonella serotypes isolated from the environment, animals, and humans in South Africa by a systematic review and meta-analysis. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed to search four databases for studies published from 1980 to 2021, that reported the antibiotic resistance profiles of Salmonella serotypes isolated in South Africa. The AR was screened from 2930 Salmonella serotypes which were isolated from 6842 samples. The Western Cape province had high pooled prevalence estimates (PPE) of Salmonella isolates with AR profiles followed by North West, Gauteng, and Eastern Cape with 94.3%, 75.4%, 59.4%, and 46.2%, respectively. The high PPE and heterogeneity were observed from environmental samples [69.6 (95% CI: 41.7−88.3), Q = 303.643, I2 = 98.353, Q-P = 0.045], animals [41.9 (95% CI: 18.5–69.5), Q = 637.355, I2 = 98.745, Q-P = 0.577], as well as animals/environment [95.9 (95% CI: 5.4−100), Q = 55.253, I2 = 96.380, Q-P = 0.300]. The majority of the salmonella isolates were resistant to sulphonamides (92.0%), enrofloxacin and erythromycin (89.3%), oxytetracycline (77.4%), imipenem (72.6%), tetracycline (67.4%), as well as trimethoprim (52.2%), among the environment, animals, and humans. The level of multidrug-resistance recorded for Salmonella isolates was 28.5% in this review. This study has highlighted the occurrence of AR by Salmonella isolates from animals, humans, and environmental samples in South Africa and this calls for a consolidated “One Health” approach for antimicrobial resistance epidemiological research, as well as the formulation of necessary intervention measures to prevent further spread.

A systemic review of literatures on human Salmonella enterica serovars in Nigeria (1999-2018)

Introduction: Salmonella infections are endemic in Nigeria. There is lack of reliable data on culture-positive Salmonella with national coverage. This systemic review of literatures was undertaken to aggregate data on culture proven cases of human Salmonellae and to determine the prevailing serotypes for disease burden estimations. Methodology: This involved comprehensive search engines of Pubmed, Google Scholar, Google and Embase for the literatures on culture positive human Salmonellae from 1999-2018. This review documented the prevalence, common Salmonella serotypes. antibiotic resistance and risk factors associated with human Salmonella infections. Results: This study revealed that 21out of 36 States in Nigeria reported Salmonella-associated diseases, spanning the six geopolitical zones. Our study revealed prevalence of 1.9% (2,732/143,756) Salmonella-bacteraemia and 16.3% (1,967/12,081) Salmonella-associated gastroenteritis. Fifty-three 53 Salmonella serotypes were identified. 39 serotypes were associated with Salmonella-bacteraemia and 31 serotypes with Salmonella-gastroenteritis. Salmonella typhi remains the commonest serotype accounting for 85.2% for Salmonella-bacteraemia and 73.1% Salmonella-gastroenteritis. S. typhimurium (3.8%) was mostly implicated invasive non-typhoidal serotype followed S. enteritidis (2.8%) among others. Human Immunodeficiency Virus-infected individuals, malnutrition was among factors predisposing Salmonella infections. Over 60% of the reported Salmonella isolates developed resistance to two or more of 23 antibiotics recorded, mostly ampicillin, cotrimoxazole, tetracycline and amoxicillin. Conclusions: This study revealed 39 Invasive and 31 non-invasive Salmonella serotypes. Ampicillin, cotrimoxazole, amoxicillin-clavulanate and tetracycline are the most frequently reported antibiotics resisted by Salmonella isolates. This antimicrobial resistance exhibited poses a threat to public health. Data generated from this review would serve as a baseline information for future surveillance studies.

Salmonella serotype prediction using the GalaxyTrakr SeqSero2 workflow v1

Salmonella serotypes are defined by two surface structures, O antigen and two H antigens. Traditional serotype determination is performed with the Salmonella serological somatic (O) and flagellar (H) tests and paired with biochemical confirmation. More than 2,600 Salmonella serotypes have been described in the White-Kauffmann-Le Minor scheme. Molecular methods for serotype determination have been developed based on genes responsible for serotype antigens. These genes are encoded in the rfb gene cluster, fliC, and fljB. SeqSero2 is a bioinformatic pipeline that uses whole genome sequence (WGS) data from pure-culture isolates to perform in silico analysis to determine the antigenic formula, including somatic (O) antigens and both flagellar (H) antigens. This provides continuity with the well-established scheme for phenotypic Salmonella serotypes. PURPOSE: This document outlines the steps required to run SeqSero2 v1.1.1 on a collection of isolates in the GalaxyTrakr environment. This is performed by utilizing a custom workflow called “SeqSero2 v1.1.1 collection workflow” and downloading the resulting table. SCOPE: This protocol covers the following tasks: 1. set up an account in GalaxyTrakr 2. Create a new history/workspace 3. Upload data 4. Execute the SeqSero2 workflow 5. Download the results

Trend of Salmonella enterica occurrence and serotypes in Sardinian pig slaughterhouses

The aim of this study was to evaluate Salmonella prevalence and serotypes in four Sardinian pig slaughterhouses. Moreover, a population study was conducted with pulsed field gel electrophoresis (PFGE). The results were compared with previous investigations carried out during years 2008 and 2014. A total of 147 samples were collected, 117 from slaughtered pigs (lymph nodes, colon content and carcass surface) and 30 from the slaughterhouse environment (surfaces in contact and not in contact with meat). Salmonella was isolated from 3.4% pig samples and was not detected from environmental samples. Comparing the results with those of previous investigations, occurrence showed a sharp decrease through the years in both animals (18.8% in 2008, 10% in 2014 and 3.4% in 2020) and environmental samples (34.1% in 2008, 3.7 in 2014, and 0% in 2020). At the same time, prevalence of carriers (pigs positive at lymph nodes and/or colon content level) showed a reduction through the years and was always lower in animals coming from local farms rather than those coming from other European Member States, probably indicating the role of stressful factors as transport in increasing Salmonella susceptibility and shedding. Salmonella serotypes were monophasic Typhimurium, Rissen and Muenchen. Overall, 13 different Salmonella serotypes were identified during the three surveys with the most prevalent being serotypes often isolated from slaughtered pigs and during human salmonellosis cases: S. Derby and S. Typhimurium in 2008, S. Anatum and S. Rissen in 2014, monophasic S. Typhimurium in 2020. Population study with pulsed field gel electrophoresis showed a high similarity between Salmonella strains belonging to the same serotype. The results of the investigations showed a decrease of Salmonella occurrence during twelve years in Sardinia, probably due to the improvement in the application of correct GMPs and GHPs at slaughterhouse and also to a reduction of the rate of carrier pigs at farm level.

Antimicrobial Resistant Salmonella Serotypes Circulating in Meat in Senegal

The Presence of antimicrobial-resistant Salmonella in food remains a real threat. The aim of this study was to determine the antimicrobial resistance profiles of Salmonella strains isolated from the most consumed types of meat in Senegal. A total of 337 samples were collected including 247 samples of raw meat and 90 of meat-based ready-made meals. Salmonella strains were isolated according to the French standard EN-ISO-6579 and serotyped according to the KWLM scheme. Antimicrobial susceptibility tests were performed with 16 discs following the agar diffusion method. Our study showed that 37% of the samples carried Salmonella and allowed the isolation of 136 strains of Salmonella. We identified 47 different serotypes including S. Kentucky (11/136: 8%), S. Brancaster (10/136: 7%), S. Chester (10/136: 7%), S. Istanbul (5/136: 4 %), and S. Agona (5/136: 4%) which were respectively the most common. Of the 136 strains, 43 (31.6%) were resistant to at least one antibiotic, of which 15.4% (21/136) were multidrug-resistant. Interestingly, S. Kentucky that was the most common, exhibited also the highest level of resistance, being at least resistant to 8 antibiotics. In conclusion, The increasing resistance and spread of S. Kentucky in meat products demand special monitoring and to be further studied.

Occurrence of Salmonella in the Cattle Production in France

Salmonella is among the most common foodborne pathogens worldwide, and can lead to acute gastroenteritis. Along with poultry, cattle production is recognized as an important source of human infection. Salmonella transmission from cattle to humans can occur through the environment, or through close contact with sick animals or their derived products. This study aimed to investigate the intestinal carriage of Salmonella spp. within French cattle production. A total of 959 cattle intestinal samples, from one of the largest French slaughterhouses, were analyzed. Isolated strains were genotyped by pulsed field gel electrophoresis (PFGE), and a sub-selection was taken by whole genome sequencing (WGS). Twenty-nine samples were positive for Salmonella spp., yielding an estimated prevalence of 3% in cattle production. Eight different Salmonella serotypes were found: Montevideo was the most prevalent (34%), followed by Mbandaka (24%) and Anatum (14%). PFGE genotyping allowed the clustering of Salmonella isolates according to their serotype. Within the clusters, some isolates presented 100% similarity. To investigate potential epidemiological links between them, WGS and core genome multilocus sequence typing (cgMLST) were used, revealing identical profiles between isolates originating from different areas and/or different animal breeds. This investigation provides new insights on Salmonella serotype epidemiology in cattle production in France.