scholarly journals Antimicrobial-Resistant Listeria Species from Retail Meat in Metro Detroit

2012 ◽  
Vol 75 (12) ◽  
pp. 2136-2141 ◽  
Author(s):  
LIZIANE S. da ROCHA ◽  
GAYATHRI U. GUNATHILAKA ◽  
YIFAN ZHANG
Keyword(s):  
Antimicrobial Resistance ◽  
Gel Electrophoresis ◽  
Tetracycline Resistance ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Listeria Species ◽  
Serotype 1 ◽  
Retail Meat ◽  
Serotype Identification ◽  
Low Prevalence

A total of 138 Listeria isolates from retail meat, including 58 Listeria welshimeri, 44 Listeria monocytogenes, and 36 Listeria innocua isolates, were characterized by antimicrobial susceptibility tests against nine antimicrobials. In addition, the 44 L. monocytogenes isolates were analyzed by serotype identification using PCR and genotyping using pulsed-field gel electrophoresis. Resistance to one or two antimicrobials was observed in 32 Listeria isolates (23.2%). No multidrug resistance was identified. Tetracycline resistance was the most common resistance phenotype and was identified in 22 Listeria isolates. A low prevalence of resistance to ciprofloxacin, erythromycin, gentamicin, and vancomycin was also detected. L. innocua isolates demonstrated the highest overall prevalence of antimicrobial resistance, 36.1%, followed by 34.1% in L. monocytogenes isolates and 6.9% in L. welshimeri isolates. Serotypes 1/2a, 1/2b, and 4b were identified in 19, 23, and 1 L. monocytogenes isolate, respectively. One isolate was untypeable. Fifteen L. monocytogenes isolates were antimicrobial resistant (12 were serotype 1/2b, 2 were 1/2a, and 1 was untypeable). A diverse population of L. monocytogenes isolates was identified, as evidenced by multiple pulsed-field gel electrophoresis patterns in the 44 isolates. The data indicate that Listeria contamination is common in retail meat. Although antimicrobial resistance still occurs at a low prevalence, multiple Listeria species can serve as reservoirs of antimicrobial resistance. Various antimicrobial susceptibilities may exist in L. monocytogenes isolates of different serotypes.

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.

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 Presence of the tet(O) Gene in Erythromycin- and Tetracycline-Resistant Strains of Streptococcus pyogenes and Linkage with either the mef(A) or the erm(A) Gene

2003 ◽  
Vol 47 (9) ◽  
pp. 2844-2849 ◽  
Author(s):  
Eleonora Giovanetti ◽  
Andrea Brenciani ◽  
Remo Lupidi ◽  
Marilyn C. Roberts ◽  
Pietro E. Varaldo
Keyword(s):  
Streptococcus Pyogenes ◽  
Resistance Genes ◽  
Gel Electrophoresis ◽  
Tetracycline Resistance ◽  
Pulsed Field Gel Electrophoresis ◽  
M Gene ◽  
Pulsed Field ◽  
Conjugative Transposons ◽  
Tetracycline Resistance Genes ◽  
Resistant Strains

ABSTRACT Sixty-three recent Italian clinical isolates of Streptococcus pyogenes resistant to both erythromycin (MICs ≥ 1 μg/ml) and tetracycline (MICs ≥ 8 μg/ml) were genotyped for macrolide and tetracycline resistance genes. We found 19 isolates carrying the mef(A) and the tet(O) genes; 25 isolates carrying the erm(A) and tet(O) genes; and 2 isolates carrying the erm(A), tet(M), and tet(O) genes. The resistance of all erm(A)-containing isolates was inducible, but the isolates could be divided into two groups on the basis of erythromycin MICs of either >128 or 1 to 4 μg/ml. The remaining 17 isolates included 15 isolates carrying the erm(B) gene and 2 isolates carrying both the erm(B) and the mef(A) genes, with all 17 carrying the tet(M) gene. Of these, 12 carried Tn916-Tn1545-like conjugative transposons. Conjugal transfer experiments demonstrated that the tet(O) gene moved with and without the erm(A) gene and with the mef(A) gene. These studies, together with the results of pulsed-field gel electrophoresis experiments and hybridization assays with DNA probes specific for the tet(O), erm(A), and mef(A) genes, suggested a linkage of tet(O) with either erm(A) or mef(A) in erythromycin- and tetracycline-resistant S. pyogenes isolates. By amplification and sequencing experiments, we detected the tet(O) gene ca. 5.5 kb upstream from the mef(A) gene. This is the first report demonstrating the presence of the tet(O) gene in S. pyogenes and showing that it may be linked with another gene and can be moved by conjugation from one chromosome to another.

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.

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.

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