Characterization of Antimicrobial-Resistant Phenotypes and Genotypes among Salmonella enterica Recovered from Pigs on Farms, from Transport Trucks, and from Pigs after Slaughter

2004 ◽  
Vol 67 (4) ◽  
pp. 698-705 ◽  
Author(s):  
WONDWOSSEN A. GEBREYES ◽  
PETER R. DAVIES ◽  
PAA-KOBINA TURKSON ◽  
W. E. MORGAN MORROW ◽  
JULIE A. FUNK ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Typhimurium ◽  
Clavulanic Acid ◽  
Gel Electrophoresis ◽  
Rank Correlation ◽  
Pulsed Field Gel Electrophoresis ◽  
Mesenteric Lymph Nodes ◽  
Chloramphenicol Resistance ◽  
Pulsed Field ◽  
Amoxicillin Clavulanic Acid

The main objectives of this study were to determine antimicrobial resistance patterns among Salmonella serotypes and to evaluate the role of transport trucks in dissemination of antimicrobial-resistant strains of Salmonella. Salmonella from groups of nursery and finishing pigs on farms, from trucks, and from pigs after slaughter were compared using serotyping, patterns of antimicrobial resistance, and pulsed-field gel electrophoresis patterns. The five farms included in the study yielded 858 isolates representing 27 Salmonella serovars. The most common resistance observed (80% of all isolates) was to tetra-cycline; resistance to ampicillin (42%), chloramphenicol (31%), amoxicillin/clavulanic acid (30%), and piperacillin (31%) also were common. We found a correlation between serovar and antimicrobial resistance. High correlation was found between Salmonella Typhimurium var. Copenhagen and chloramphenicol resistance (Spearman rank correlation, ρ = 0.7). Multidrug resistance was observed primarily in Salmonella Typhimurium var. Copenhagen (94%) and Salmonella Typhimurium (93%) and was much less common in the other common serovars, including Salmonella Derby (7%) and Salmonella Heidelberg (8%). Of the 225 isolates exhibiting the most common pentaresistance pattern in this study, amoxicillin/clavulanic acid–ampicillin–chloramphenicol–piperacillin–tetracycline, 220 (98%) were Salmonella Typhimurium var. Copenhagen, and 86% of the isolates of this serovar had this pattern. Isolates from the trucks were similar, based on pulsed-field gel electrophoresis patterns, to those from the cecum and mesenteric lymph nodes of pigs on two of the farms, suggesting the probable infection of pigs during transport. Class I integrons were also common among various serovars.

Characterization and Antimicrobial Resistance of Salmonella Typhimurium Isolates from Clinically Diseased Pigs in Korea

2016 ◽  
Vol 79 (11) ◽  
pp. 1884-1890 ◽  
Author(s):  
SANG-IK OH ◽  
JONG WAN KIM ◽  
MYEONGJU CHAE ◽  
JI-A JUNG ◽  
BYUNGJAE SO ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Typhimurium ◽  
Resistance Genes ◽  
Gel Electrophoresis ◽  
Salmonella Enteritidis ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Antimicrobial Resistance Genes

ABSTRACT This study investigated the prevalence of Salmonella enterica serovar and antimicrobial resistance in Salmonella Typhimurium isolates from clinically diseased pigs collected from 2008 to 2014 in Korea. Isolates were also characterized according to the presence of antimicrobial resistance genes and pulsed-field gel electrophoresis patterns. Among 94 Salmonella isolates, 81 (86.2%) were identified as being of the Salmonella Typhimurium serotype, followed by Salmonella Derby (6 of 94, 6.4%), Salmonella 4,[5],12:i:− (4 of 94, 4.3%), Salmonella Enteritidis (2 of 94, 2.1%), and Salmonella Brandenburg (1 of 94, 1.1%). The majority of Salmonella Typhimurium isolates were resistant to tetracycline (92.6%), followed by streptomycin (88.9%) and ampicillin (80.2%). Overall, 96.3% of Salmonella Typhimurium isolates showed multidrug-resistant phenotypes and commonly harbored the resistance genes blaTEM (64.9%), flo (32.8%), aadA (55.3%), strA (58.5%), strB (58.5%), sulII (53.2%), and tetA (61.7%). The pulsed-field gel electrophoresis analysis of 45 Salmonella Typhimurium isolates from individual farms revealed 27 distinct patterns that formed one major and two minor clusters in the dendrogram analysis, suggesting that most of the isolates (91.1%) from diseased pigs were genetically related. These findings can assist veterinarians in the selection of appropriate antimicrobial agents to combat Salmonella Typhimurium infections in pigs. Furthermore, they highlight the importance of continuous surveillance of antimicrobial resistance and genetic status in Salmonella Typhimurium for the detection of emerging resistance trends.

scholarly journals Molecular epidemiology and antimicrobial resistance of Salmonella isolates from broilers and pigs in Thailand

2019 ◽  
Vol 12 (8) ◽  
pp. 1311-1318 ◽  
Author(s):  
Dusadee Phongaran ◽  
Seri Khang-Air ◽  
Sunpetch Angkititrakul
Keyword(s):  
Antimicrobial Resistance ◽  
Gel Electrophoresis ◽  
Animal Species ◽  
Antimicrobial Agents ◽  
Genetic Relatedness ◽  
Pulsed Field Gel Electrophoresis ◽  
Resistance Pattern ◽  
Salmonella Spp ◽  
Pulsed Field ◽  
Amoxicillin Clavulanate

Aim: This study aimed to determine the prevalence and antimicrobial resistance pattern of Salmonella spp., and the genetic relatedness between isolates from broilers and pigs at slaughterhouses in Thailand. Materials and Methods: Fecal samples (604 broilers and 562 pigs) were collected from slaughterhouses from April to July 2018. Salmonella spp. were isolated and identified according to the ISO 6579:2002. Salmonella-positive isolates were identified using serotyping and challenged with nine antimicrobial agents: Amoxicillin/clavulanate (AMC, 30 μg), ampicillin (AMP, 10 μg), ceftazidime (30 μg), chloramphenicol (30 μg), ciprofloxacin (CIP, 5 μg), nalidixic acid (NAL, 30 μg), norfloxacin (10 μg), trimethoprim/sulfamethoxazole (SXT, 25 μg), and tetracycline (TET, 30 μg). Isolates of the predominant serovar Salmonella Typhimurium were examined for genetic relatedness using pulsed-field gel electrophoresis (PFGE). Results: Salmonella was detected in 18.05% of broiler isolates and 37.54% of pig isolates. The most common serovars were Kentucky, Give, and Typhimurium in broilers and Rissen, Typhimurium, and Weltevreden in pigs. Among broilers, isolates were most commonly resistant to antibiotics, NAL, AMP, TET, AMC, and CIP. Pig isolates most commonly exhibited antimicrobial resistance against AMP, TET, and SXT. Based on PFGE results among 52 S. Typhimurium isolates from broilers and pigs, a high genetic relatedness between broiler and pig isolates (85% similarity) in Cluster A and C from PFGE result was identified. Conclusion: The results revealed high cross-contamination between these two animal species across various provinces in Thailand. Keywords: antimicrobial resistance, broilers, pigs, pulsed-field gel electrophoresis, Salmonella spp.

Isolation of Salmonella Typhimurium from Outbreak-Associated Cake Mix

2007 ◽  
Vol 70 (4) ◽  
pp. 997-1001 ◽  
Author(s):  
GUODONG ZHANG ◽  
LI MA ◽  
NEHAL PATEL ◽  
BALA SWAMINATHAN ◽  
STEPHANIE WEDEL ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Gel Electrophoresis ◽  
Ice Cream ◽  
Pulsed Field Gel Electrophoresis ◽  
Outbreak Investigation ◽  
Cake Batter ◽  
Pulsed Field ◽  
Enrichment Cultures ◽  
Broth Enrichment ◽  
Better Than

During May and June of 2005, 26 persons in several states were infected by a single strain (isolates indistinguishable by pulsed-field gel electrophoresis) of Salmonella enterica serotype Typhimurium after eating cake batter ice cream. The cake mix used to prepare the cake batter in the ice cream was implicated by epidemiologic investigation as the source of Salmonella contamination. Initial tests did not detect Salmonella in cake mix collected during the outbreak investigation. The objective of this study was to evaluate different procedures to isolate Salmonella from the implicated cake mix, cake, and ice cream. All outbreak-associated food samples (14 samples) were collected during the outbreak investigation by health departments of several of the states involved. Different combinations of Salmonella isolation procedures, including sample size, preenrichment broth, enrichment broth, enrichment temperature, and isolation medium, were used. Salmonella Typhimurium was isolated from two cake mix samples; the food isolates were indistinguishable from the outbreak pattern by pulsed-field gel electrophoresis subtyping. Universal preenrichment broth was substantially better than was lactose broth for preenrichment, and tetrathionate broth was better than was Rappaport-Vassiliadis broth for isolating Salmonella from the two positive cake mix samples. Although more typical Salmonella colonies were observed on plates from enrichment cultures grown at 35°C, more confirmed Salmonella isolates were obtained from plates of enrichment cultures grown at 42°C. Brilliant green agar, xylose lysine tergitol 4 agar, xylose lysine desoxycholate agar, Hektoen enteric agar, and bismuth sulfite agar plates were equally effective in isolating Salmonella from cake mix. The best combination of preenrichment-enrichment conditions for isolating the outbreak strain of Salmonella was preenrichment of cake mix samples in universal preenrichment broth at 35oC for 24 h, followed by enrichment in tetrathionate broth at 42°C for 24 h.

Antimicrobial Resistance of Salmonella enterica Isolates from Bulk Tank Milk and Milk Filters in the United States†

2013 ◽  
Vol 76 (1) ◽  
pp. 18-25 ◽  
Author(s):  
J. S. VAN KESSEL ◽  
J. SONNIER ◽  
S. ZHAO ◽  
J. S. KARNS
Keyword(s):  
Antimicrobial Resistance ◽  
Gel Electrophoresis ◽  
Salmonella Enterica ◽  
Pulsed Field Gel Electrophoresis ◽  
Class I ◽  
Bulk Tank Milk ◽  
Pulsed Field ◽  
Extended Spectrum ◽  
Class I Integrons ◽  
Bulk Tank

Salmonella isolates were recovered from bulk tank milk as part of the National Animal Health Monitoring System (NAHMS) Dairy 2002 and 2007 surveys. In-line milk filters were also tested in the 2007 survey. The objective of this study was to determine the prevalence of antimicrobial resistance among Salmonella enterica isolates from bulk milk and milk filters in the NAHMS Dairy 2002 and 2007 surveys and to further characterize resistant isolates. Susceptibilities to 15 antibiotics were determined for 176 Salmonella isolates of 26 serotypes using an automated antimicrobial susceptibility system. Resistant isolates were screened by PCR for the presence of the extended-spectrum β-lactamase (blaCMY) gene and class I integrons and further characterized by pulsed-field gel electrophoresis. Thirty isolates (17.0%) representing six S. enterica serotypes exhibited resistance to at least one antimicrobial agent (serotypes Newport [14 of 14 isolates exhibited resistance], Dublin [7 of 7], Typhimurium [3 of 5], Kentucky [4 of 22], Anatum [1 of 13], and Infantis [1 of 2]). Twenty isolates (11.4%), including all 14 Newport, 3 Dublin, 2 Typhimurium, and 1 Infantis isolate, displayed the typical multidrug-resistant, blaCMY-positive (MDR-AmpC) phenotype which included resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline, plus resistance to amoxicillin–clavulanic acid and extended-spectrum cephalosporins. Five of the MDR-AmpC isolates carried class I integrons (2.8%). Two-enzyme (XbaI and BlnI) pulsed-field gel electrophoresis discerned clades within serotypes and, together with the resistance profiles, identified strains that appeared to have persisted temporally and geographically. These results suggest that there is a low but appreciable risk of infection with MDR Salmonella from consumption of nonpasteurized milk and dairy products.

scholarly journals Class 1 Integrons Increase Trimethoprim-Sulfamethoxazole MICs against Epidemiologically Unrelated Stenotrophomonas maltophilia Isolates

2004 ◽  
Vol 48 (2) ◽  
pp. 666-669 ◽  
Author(s):  
Raquel Barbolla ◽  
Mariana Catalano ◽  
Betina E. Orman ◽  
Angela Famiglietti ◽  
Carlos Vay ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Nosocomial Infection ◽  
Gel Electrophoresis ◽  
Stenotrophomonas Maltophilia ◽  
Pulsed Field Gel Electrophoresis ◽  
Gram Negative ◽  
Pulsed Field ◽  
Class 1 Integrons ◽  
Resistance Determinants ◽  
Class 1

ABSTRACT Twenty-five plasmid-specified antimicrobial resistance determinants common to gram-negative bacilli from nosocomial infection were investigated from 31 Stenotrophomonas maltophilia isolates. Twenty-four clones were identified by pulsed-field gel electrophoresis, and in three clones that exhibited an increased trimethoprim-sulfamethoxazole MIC, the sul1 determinant was found. These results support not only the higher spread of class 1 integrons compared to other mechanisms but also the potential limitation of using trimethoprim-sulfamethoxazole for therapy of severe S. maltophilia infections.

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