Detection of Plasmid-Mediated Tigecycline Resistance Gene tet(X4) in a Salmonella Enterica Serovar Llandoff Isolate

ABSTRACTSalmonellosis is one of the most common causes of food-borne disease in the United States. Increasing antimicrobial resistance and corresponding increases in virulence present serious challenges. Currently, empirical therapy for invasiveSalmonella entericainfection includes either ceftriaxone or ciprofloxacin (E. L. Hohmann, Clin. Infect. Dis. 32:263–269, 2001). TheblaCMY-2gene confers resistance to ceftriaxone, the antimicrobial of choice for pediatric patients with invasiveSalmonella entericainfections, making these infections especially dangerous (J. M. Whichard et al., Emerg. Infect. Dis. 11:1464–1466, 2005). We hypothesized thatblaCMY-2-positiveSalmonella entericawould exhibit increased MICs to multiple antimicrobial agents and increased resistance gene expression following exposure to ceftriaxone using a protocol that simulated a patient treatmentin vitro. SevenSalmonella entericastrains survived a simulated patient treatmentin vitroand, following treatment, exhibited a significantly increased ceftriaxone MIC. Not only would these isolates be less responsive to further ceftriaxone treatment, but because theblaCMY-2genes are commonly located on large, multidrug-resistant plasmids, increased expression of theblaCMY-2gene may be associated with increased expression of other drug resistance genes located on the plasmid (N. D. Hanson and C. C. Sanders, Curr. Pharm. Des. 5:881–894, 1999). The results of this study demonstrate that a simulated patient treatment with ceftriaxone can alter the expression of antimicrobial resistance genes, includingblaCMY-2andfloRinS. entericaserovar Typhimurium andS. entericaserovar Newport. Additionally, we have shown increased MICs following a simulated patient treatment with ceftriaxone for tetracycline, amikacin, ceftriaxone, and cefepime, all of which have resistance genes commonly located on CMY-2 plasmids. The increases in resistance observed are significant and may have a negative impact on both public health and antimicrobial resistance ofSalmonella enterica.

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Characterization of class 1 integron resistance gene cassettes in Salmonella enterica serovars Oslo and Bareily from imported seafood

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkl416 ◽

2006 ◽

Vol 58 (6) ◽

pp. 1308-1310 ◽

Cited By ~ 20

Author(s):

A. A. Khan ◽

C.-M. Cheng ◽

K. T. Van ◽

C. S. West ◽

M. S. Nawaz ◽

...

Keyword(s):

Resistance Gene ◽

Salmonella Enterica ◽

Class 1 Integron ◽

Gene Cassettes ◽

Class 1

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Transfer of Plasmid-Mediated CTX-M-9 from Salmonella enterica Serotype Virchow to Enterobacteriaceae in Human Flora-Associated Rats Treated with Cefixime

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00310-09 ◽

2009 ◽

Vol 54 (1) ◽

pp. 164-169 ◽

Cited By ~ 15

Author(s):

S. Faure ◽

A. Perrin-Guyomard ◽

J. M. Delmas ◽

P. Chatre ◽

M. Laurentie

Keyword(s):

Resistance Gene ◽

Salmonella Enterica ◽

Transfer Rate ◽

Intestinal Flora ◽

Antibiotic Use ◽

Animal Origin ◽

E Coli ◽

Animal Strain ◽

Human Flora ◽

Therapeutic Doses

ABSTRACT Food animals are a potential source of CTX-M resistance genes for humans. We evaluated the transfer of the bla CTX-M-9 gene from an animal strain of Salmonella enterica serotype Virchow to Enterobacteriaceae of the human intestinal flora by using human flora-associated (HFA) rats with and without cefixime treatment. In the absence of antibiotic, no transconjugant enterobacteria were found in the feces of HFA rats. However, the transfer rate was high if Escherichia coli J5 recipient strains were coinoculated orally with Salmonella. S. enterica serotype Virchow persisted in the rat fecal flora both during and after treatment with therapeutic doses of cefixime. The drug did not increase the transfer rate, and E. coli J5 transconjugants were eliminated from the flora before the end of cefixime treatment. No cefixime was recovered in the rat feces. In the presence of recipient strains, the bla CTX-M-9 resistance gene was transferred from a strain of animal origin to the human intestinal flora, although transconjugant colonization was transient. Antibiotic use enhanced the persistence of donor strains, increasing the resistance gene pool and the risk of its spread.

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Multi-Drug Resistance in Salmonella enterica: Efflux Mechanisms and Their Relationships with the Development of Chromosomal Resistance Gene Clusters

Current Drug Targets ◽

10.2174/138945006777709548 ◽

2006 ◽

Vol 7 (7) ◽

pp. 849-860 ◽

Cited By ~ 31

Author(s):

Teresa Quinn ◽

Rebecca O'Mahony ◽

Alan Baird ◽

Denise Drudy ◽

Paul Whyte ◽

...

Keyword(s):

Drug Resistance ◽

Resistance Gene ◽

Salmonella Enterica ◽

Gene Clusters ◽

Multi Drug Resistance

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Characterization of Quinolone Resistance in Salmonella enterica from Farm Animals in China

Journal of Food Protection ◽

10.4315/0362-028x.jfp-17-068 ◽

2017 ◽

Vol 80 (10) ◽

pp. 1742-1748 ◽

Cited By ~ 8

Author(s):

Ting-Ting Cao ◽

Guo-Hui Deng ◽

Liang-Xing Fang ◽

Run-Shi Yang ◽

Jian Sun ◽

...

Keyword(s):

Resistance Gene ◽

Salmonella Enterica ◽

Antimicrobial Agents ◽

Multidrug Resistant ◽

Quinolone Resistance ◽

Farm Animals ◽

Gyra Gene ◽

Republic Of China ◽

Resistance Plasmids

ABSTRACT This study was focused on the prevalence and antimicrobial susceptibilities of Salmonella directly isolated at animal clinics in Guangdong, People's Republic of China. The isolation rates from chickens, ducks, and pigs were 11.3% (11 of 97 samples), 15.4% (53 of 344 samples), and 3.0% (13 of 434 samples), respectively. Among the 77 Salmonella enterica isolates, the most predominant serovar was Typhimurium (81.8%, 63 isolates), followed by serovars Meleagridis (2.6%, 2 isolates) and Abaetetuba (1.3%, 1 isolate). Salmonella isolates were resistant to ciprofloxacin (16.9% of isolates) and nalidixic acid (66.2% of isolates), and 68 isolates (88.3%) were multidrug resistant, displaying resistance to three or more classes of antimicrobial agents. Eighteen isolates (23.4%) had at least one plasmid-mediated quinolone resistance gene, which was identified using PCR and DNA sequencing. The most prevalent plasmid-mediated quinolone resistance gene was aac(6′)-Ib-cr, found in 14 isolates (18.2%), followed by oqxAB (9.1%) and qnrS (7.8%). Alterations in the gyrA gene were detected in 24 (57.1%) of 42 strains with a ciprofloxacin MIC of ≥0.25 μg/mL; the same level of susceptibility was found for enrofloxacin. Six types of mutations were found in the quinolone resistance determining regions of gyrA, and the predominant one (S83Y) was found singly in 15 (62.5%) of 24 isolates. We also found 22 different pulsed-field gel electrophoresis types among the Salmonella isolates. The Salmonella serovars and MICs of ciprofloxacin were similar within clusters, although individual differences were noted. This finding suggests that resistance plasmids were horizontally transmitted but also clonally spread.

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Large Drug Resistance Virulence Plasmids of Clinical Isolates of Salmonella enterica Serovar Choleraesuis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.8.2299-2303.2001 ◽

2001 ◽

Vol 45 (8) ◽

pp. 2299-2303 ◽

Cited By ~ 50

Author(s):

Chishih Chu ◽

Cheng-Hsun Chiu ◽

Wan-Yu Wu ◽

Chi-Hong Chu ◽

Tsui-Ping Liu ◽

...

Keyword(s):

Drug Resistance ◽

Resistance Gene ◽

Resistance Genes ◽

Dna Hybridization ◽

Salmonella Enterica ◽

Laboratory Strain ◽

Clinical Isolates ◽

Dilution Method ◽

Virulence Plasmid ◽

Multiple Drugs

ABSTRACT Salmonella enterica serovar Choleraesuis generally causes systemic human salmonellosis without diarrhea, and therefore, antimicrobial treatment is essential for such patients. The drug resistance information on this organism is thus of high value. Serovar Choleraesuis usually harbors a virulence plasmid (pSCV) of 50 kb in size. Of the 16 clinical isolates identified to be serovar Choleraesuis, all except one harbored a pSCV and seven of them carried a pSCV of more than 125 kb in size. A pSCV was defined as a plasmid carrying spvC and characteristic deletions detected by PCR and by DNA-DNA hybridization (for the former criterion). The results of PCR, restriction fragment profiles, and Southern DNA-DNA hybridizations of the profiles all indicated that such larger pSCVs were derived from the 50-kb plasmid recombined with non-pSCVs found in some clinical isolates. Fifteen of the 17 strains, including a laboratory strain, were then tested for drug resistance against 16 antibiotics with E-test and the dilution method. The laboratory strain, which harbored a 50-kb pSCV and a 6-kb non-pSCV, was resistant only to sulfonamides (SUL), and its resistance gene, sulII, checked with PCR and DNA-DNA hybridization, was located on the 6-kb non-pSCV. All 14 clinical strains were resistant to multiple drugs. Of the 14, 7 were resistant to SUL, and the resistance gene was located on a plasmid. ThesulII gene, but not bla TEM-1, was carried only on the 6-kb non-pSCV. Of the remaining six large plasmids, three of 90 kb, two of 136 kb, and one of 140 kb, the last three were pSCVs and carried the other SUL gene (sulI) and thebla TEM-1 gene. The six strains were also resistant to trimethoprim-sulfamethoxazole. None of the 50-kb pSCVs carried resistance genes. These drug resistance genes on the large pSCVs were apparently also acquired through recombination.

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Salmonella genomic island 1-J variants associated with change in the antibiotic resistance gene cluster in multidrug-resistant Salmonella enterica serovar Virchow isolated from humans, Taiwan, 2004–2006

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.2011.03464.x ◽

2012 ◽

Vol 18 (1) ◽

pp. 47-53 ◽

Cited By ~ 14

Author(s):

C. Chu ◽

B. Doublet ◽

Y.-L. Lee ◽

A. Cloeckaert ◽

C.-S. Chiou ◽

...

Keyword(s):

Antibiotic Resistance ◽

Gene Cluster ◽

Resistance Gene ◽

Salmonella Enterica ◽

Genomic Island ◽

Antibiotic Resistance Gene ◽

Multidrug Resistant ◽

Resistance Gene Cluster

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Novel plasmid-mediated colistin resistance mcr-4 gene in Salmonella and Escherichia coli, Italy 2013, Spain and Belgium, 2015 to 2016

Eurosurveillance ◽

10.2807/1560-7917.es.2017.22.31.30589 ◽

2017 ◽

Vol 22 (31) ◽

Cited By ~ 232

Author(s):

Alessandra Carattoli ◽

Laura Villa ◽

Claudia Feudi ◽

Ludovica Curcio ◽

Serenella Orsini ◽

...

Keyword(s):

Escherichia Coli ◽

Resistance Gene ◽

Salmonella Enterica ◽

Gene Variant ◽

Colistin Resistance ◽

E Coli ◽

Novel Gene ◽

Serovar Typhimurium

A novel mcr colistin resistance gene was identified in a strain of Salmonella enterica, monophasic variant of serovar Typhimurium (4,5,12:i:- ), isolated from a pig at slaughter in Italy in 2013, and in Escherichia coli strains collected during routine diagnostic of post-weaning diarrhoea in pigs from Spain and Belgium in 2015 and 2016. Immediate implementation of mcr-screening including this novel gene variant is required for Salmonella and E. coli from humans and food-producing animals in Europe.

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