Longitudinal study of distributions of similar antimicrobial-resistant Salmonella serovars in pigs and their environment in two distinct swine production systems

The aim of this longitudinal study was to determine and compare the prevalences and genotypic profiles of antimicrobial-resistant (AR) Salmonella isolates from pigs reared in antimicrobial-free (ABF) and conventional production systems at farm, at slaughter, and in their environment. We collected 2,889 pig fecal and 2,122 environmental (feed, water, soil, lagoon, truck, and floor swabs) samples from 10 conventional and eight ABF longitudinal cohorts at different stages of production (farrowing, nursery, finishing) and slaughter (postevisceration, postchill, and mesenteric lymph nodes [MLN]). In addition, we collected 1,363 carcass swabs and 205 lairage and truck samples at slaughter. A total of 1,090 Salmonella isolates were recovered from the samples; these were isolated with a significantly higher prevalence in conventionally reared pigs (4.0%; n = 66) and their environment (11.7%; n = 156) than in ABF pigs (0.2%; n = 2) and their environment (0.6%; n = 5) (P < 0.001). Salmonella was isolated from all stages at slaughter, including the postchill step, in the two production systems. Salmonella prevalence was significantly higher in MLN extracted from conventional carcasses than those extracted from ABF carcasses (P < 0.001). We identified a total of 24 different serotypes, with Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Anatum, Salmonella enterica serovar Infantis, and Salmonella enterica serovar Derby being predominant. The highest frequencies of antimicrobial resistance (AR) were exhibited to tetracycline (71%), sulfisoxazole (42%), and streptomycin (17%). Multidrug resistance (resistance to ≥3 antimicrobials; MDR) was detected in 27% (n = 254) of the Salmonella isolates from the conventional system. Our study reports a low prevalence of Salmonella in both production systems in pigs on farms, while a higher prevalence was detected among the carcasses at slaughter. The dynamics of Salmonella prevalence in pigs and carcasses were reciprocated in the farm and slaughter environment, clearly indicating an exchange of this pathogen between the pigs and their surroundings. Furthermore, the phenotypic and genotypic fingerprint profile results underscore the potential role played by environmental factors in dissemination of AR Salmonella to pigs

Unilateral epididymitis associated with salmonella bacteremia in a dog

This report describes the clinical features, diagnosis and treatment of a dog with unilateral epididymitis associated with Salmonella spp. bacteremia. Fever and an enlarged and painful testicle were the main clinical signs that resulted in referral for diagnostic evaluation. Unilateral septic epididymitis was diagnosed via ultrasonography of the genitourinary tract and aerobic culture of scrotal fluid, urine and blood, which yielded heavy growth of Salmonella spp. Pulsed-field gel electrophoresis (PFGE) confirmed the presence of Salmonella javiana. Following antibiotic therapy there was total resolution of clinical signs, and no Salmonella was isolated from a post-treatment urine culture. The source of infection was unknown, however an environmental exposure was suspected. Although infrequent, infection with Salmonella spp. should be included in the differential diagnosis of canine epididymitis. Given the major zoonotic importance of salmonellosis, and to prevent re-infection after treatment, the source of the infection should be investigated and eliminated, if possible

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Not AvailableShiga toxigenic Escherichia coli (STEC) O157 and several other serogroups of non-O157 STEC strains present as commensalism bacteria in small ruminants that possess a high potential of attaining pathogenic virulent genetic elements. The pathogenicity of non-O157 strains is emerging progressively in animals as well as in humans especially in the rural areas as they get transmitted through unsanitary practices of living, consumption of uncooked meat and milk, human-livestock close proximity as well as within livestock pathogenic bacterial transmission. The present study was carried out to determine the prevalence of non-O157 E.coli isolates and characterize based on clinical history, antibiotic sensitivity testing, multiplex PCR (mPCR) detection of virulence genes, genotype identification using pulse field gel electrophoresis (PFGE) and polyacrylamide gel electrophoretic separation of antigenic proteins to determine their prevalence, virulence and genetic comparison between host and environment for epidemiological significance. A total of 300 E.coli isolates were recovered from rectal swabs of goats and their surrounding environment over a period of one year (2016–2017) by selective isolation. Among which 50 isolates were confirmed to be from the non-O157 E.coli family. The mPCR analysis of these 50 isolates revealed the presence of two or more virulent genes, viz., hylA (90%), fliC (74%), eaeA (56%), stx1 (48%) and stx2 (22%).Four isolates exhibited multidrug-resistance to amoxiclav, doxycycline, ciprofloxacin and ceftriazone. The PFGE fingerprint profile showed six major clusters at 100% similarity from the 50 isolates. The major antigenic proteins identified from the isolates were stx1A, stx2B and fliC. This study has significant implications for understanding the molecular diversity of emerging pathotypes of non-O157 in young goats in terms of virulence and epidemiological aspects.Not Availabl

Not Available

Not AvailableShiga toxigenic Escherichia coli (STEC) O157 and several other serogroups of non-O157 STEC strains present as commensalism bacteria in small ruminants that possess a high potential of attaining pathogenic virulent genetic elements. The pathogenicity of non-O157 strains is emerging progressively in animals as well as in humans especially in the rural areas as they get transmitted through unsanitary practices of living, consumption of uncooked meat and milk, human-livestock close proximity as well as within livestock pathogenic bacterial transmission. The present study was carried out to determine the prevalence of non-O157 E.coli isolates and characterize based on clinical history, antibiotic sensitivity testing, multiplex PCR (mPCR) detection of virulence genes, genotype identification using pulse field gel electrophoresis (PFGE) and polyacrylamide gel electrophoretic separation of antigenic proteins to determine their prevalence, virulence and genetic comparison between host and environment for epidemiological significance. A total of 300 E.coli isolates were recovered from rectal swabs of goats and their surrounding environment over a period of one year (2016–2017) by selective isolation. Among which 50 isolates were confirmed to be from the non-O157 E.coli family. The mPCR analysis of these 50 isolates revealed the presence of two or more virulent genes, viz., hylA (90%), fliC (74%), eaeA (56%), stx1 (48%) and stx2 (22%).Four isolates exhibited multidrug-resistance to amoxiclav, doxycycline, ciprofloxacin and ceftriazone. The PFGE fingerprint profile showed six major clusters at 100% similarity from the 50 isolates. The major antigenic proteins identified from the isolates were stx1A, stx2B and fliC. This study has significant implications for understanding the molecular diversity of emerging pathotypes of non-O157 in young goats in terms of virulence and epidemiological aspects.Not Availabl

Class 1 integron-borne cassettes harboring blaCARB-2 gene in multidrug-resistant and virulent Salmonella Typhimurium ST19 strains recovered from clinical human stool samples, United States.

International lineages, such as Salmonella Typhimurium sequence type (ST) 19, are most often associated with foodborne diseases and deaths in humans. In this study, we compared the whole-genome sequences of five S. Typhimurium strains belonging to ST19 recovered from clinical human stool samples in North Carolina, United States. Overall, S. Typhimurium strains displayed multidrug-resistant profile, being resistance to critically and highly important antimicrobials including ampicillin, ticarcillin/clavulanic acid, streptomycin and sulfisoxazole, chloramphenicol, tetracycline, respectively. Interestingly, all S. Typhimurium strains carried class 1 integron (intl1) and we were able to describe two genomic regions surrounding blaCARB-2 gene, size 4,062 bp and 4,422 bp for S. Typhimurium strains (HS5344, HS5437, and HS5478) and (HS5302 and HS5368), respectively. Genomic analysis for antimicrobial resistome confirmed the presence of clinically important genes, including blaCARB-2, aac(6')-Iaa, aadA2b, sul1, tetG, floR, and biocide resistance genes (qacEΔ1). S. Typhimurium strains harbored IncFIB plasmid containing spvRABCD operon, as well as rck and pef virulence genes, which constitute an important apparatus for spreading the virulence plasmid. In addition, we identified several virulence genes, chromosomally located, while the phylogenetic analysis revealed clonal relatedness among these strains with S. enterica isolated from human and non-human sources obtained in European and Asian countries. Our results provide new insights into this unusual class 1 integron in virulent S. Typhimurium strains that harbors a pool of genes acting as potential hotspots for horizontal gene transfer providing readily adaptation to new surrounds, as well as being crucially required for virulence in vivo. Therefore, continuous genomic surveillance is an important tool for safeguarding human health