Characterization of plasmids conferring resistance to gentamicin and apramycin in strains ofSalmonella typhimuriumphage type 204c isolated in Britain

SUMMARYInSalmonella typhimuriumphage type 204c isolated in Britain, gentamicin resistance is specified by plasmids of the I1compatibility group which also confer resistance to apramycin. These plasmids have been subdivided into three types within the I1group on the basis of their antibiotic resistance specificity, their ability to produce colicin Ib and their restriction enzyme digest fragmentation patterns. All three have been identified in strains from cattle, but as yet only two types have been found in strains from humans.It is suggested that the use of apramyein in animal husbandry is responsible for the appearance of gentamicin resistance in multiresistant strains of phage type 204 c, a phage type already epidemic in bovine animals and with an increasing incidence in humans.

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Gentamicin-resistantSalmonella typhimuriumphage type 204c: molecular studies and strain diversity in a putative bovine outbreak

Epidemiology and Infection ◽

10.1017/s0950268800048834 ◽

1991 ◽

Vol 107 (1) ◽

pp. 213-223 ◽

Cited By ~ 3

Author(s):

D. J. Platt ◽

I. Smith

Keyword(s):

Antibiotic Resistance ◽

Restriction Enzyme ◽

Phage Type ◽

Resistance Pattern ◽

Molecular Evidence ◽

Strain Diversity ◽

Temporal Clustering ◽

Antibiotic Resistance Pattern ◽

Molecular Studies ◽

Gentamicin Resistance

SUMMARYAs part of the investigation of a putative bovine outbreak, 13 isolates of Salmonellatyphimuriumphage type 204c were subjected to plasmid analysis.Plasmid profiles suggested that several distinct strains were involved and these observations were supported by minor variations in antibiotic resistance pattern. Restriction enzyme fingerprinting and conjugational segregation of the plasmids confirmed these findings. Although 12 of the 13 isolates were resistant to gentamicin, resistance was conferred by 4 distinct plasmids; 3 of these belonged to Inc I and were distantly related on the basis of restriction fingerprints and the fourth was a resistant derivative of the 60 MDaS. typhimuriumserotype-specific plasmid. The molecular evidence refuted the hypothesis that geographical and temporal clustering of these gentamicin-resistant isolates could be explained on the basis of a single epidmiological episode.

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Assessment of antibiotic resistance in starter and non-starter lactobacilli of food origin

Acta Veterinaria Brno ◽

10.2754/avb202089040401 ◽

2020 ◽

Vol 89 (4) ◽

pp. 401-411

Author(s):

Marta Dušková ◽

Monika Morávková ◽

Jakub Mrázek ◽

Martina Florianová ◽

Lenka Vorlová ◽

...

Keyword(s):

Antibiotic Resistance ◽

Horizontal Transmission ◽

Acquired Resistance ◽

Minimal Inhibitory Concentrations ◽

Adjunct Cultures ◽

Microdilution Method ◽

Safe Food ◽

Multiresistant Strains ◽

Adjunct Culture

The absence of acquired resistance to antimicrobials has become an important criterion in evaluation of the biosafety of lactobacilli used as industrial starter or probiotic cultures. The aim of this study was to assess antibiotic resistance in starter and non-starter lactobacilli of food origin. Minimal inhibitory concentrations of ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline and vancomycin were established in 81 strains of lactobacilli (L. acidophilus, L. animalis, L. brevis, L. curvatus, L. delbrueckii, L. fermentum, L. helveticus, L. paracasei, L. plantarum, L. rhamnosus and L. sakei) by the microdilution method. The strains were classified as susceptible or resistant to antimicrobials based on the cut-off values according to the EFSA guideline. Sixty-two strains (77% food isolates, 76% starter or adjunct cultures) were resistant to at least one antimicrobial agent (the most frequently to aminoglycosides). Adjunct cultures showed a higher antibiotic resistance (80%) than starters (60%). Four multiresistant strains (3 food isolates, 1 adjunct culture) were analyzed by whole genome sequencing. One potentially transferable aadE gene (responsible for streptomycin resistance) was detected only in one multi-drug resistant strain of L. animalis originating from an adjunct culture. Thus, there is a risk of horizontal transmission of this gene. It is necessary to eliminate such strains from use in the food industry. This study provides relevant data concerning the use of lactobacilli in safe food production. To ensure food safety, detailed characterization of resistance to antimicrobials is necessary not only in starter strains but also in non-starter lactic acid bacteria isolated from food products.

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The distribution of serotype-specific plasmids among different subgroups of strains ofSalmonella entericaserotype Enteritidis: characterization of molecular variants by restriction enzyme fragmentation patterns

Epidemiology and Infection ◽

10.1017/s0950268800051888 ◽

1995 ◽

Vol 114 (1) ◽

pp. 25-40 ◽

Cited By ~ 11

Author(s):

S. C. Rankin ◽

C. E. Benson ◽

D. J. Platt

Keyword(s):

Restriction Enzyme ◽

Salmonella Enterica ◽

Phage Type ◽

Restriction Enzymes ◽

Additional Restriction ◽

Fragmentation Pattern ◽

Phage Types ◽

Molecular Variants ◽

Fragmentation Patterns

SUMMARYFour hundred and thirty-four isolates ofSalmonella entericaserotype Enteritidis were studied. They were grouped into five subsets defined by either the collection criteria or the parameter which formed the basis for subsequent analysis. Seventy-seven per cent harboured the serotype-specific plasmid (SSP). In 55% of the isolates this was the sole plasmid. Molecular variation in the SSP was detected in 17 (5%) of the isolates on the basis of restriction enzyme fragmentation pattern (REFP) analysis usingPstI andSmaI. The SSP variants were further characterized using additional restriction enzymes chosen to optimize the information content and analysed using a coefficient of similarity.A variant SSP designated pOG690 showed greater resemblance to the SSP ofSalmonella entericaserotype Typhimurium than Enteritidis; 89% and 68% respectively forPstI and 79% and 55% respectively forSmaI. In respect of thePstI data pOG690 shared at least 55 kb of DNA with the Typhimurium SSP and 37 kb with the SSP of Enteritidis. This variant was associated with poultry (duck, goose, chicken) and all isolates belonged to phage type 9b. Other variants were associated with phage types 4, 6, 6a, 9a, 11, 15 and 24. The epidemiological implications of these results are discussed.

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Characterization of resistance plasmids and carried phages in an epidemic clone of multi-resistantSalmonella typhimuriumin India

Journal of Hygiene ◽

10.1017/s0022172400070066 ◽

1982 ◽

Vol 88 (2) ◽

pp. 193-204 ◽

Cited By ~ 27

Author(s):

J. A. Frost ◽

B. Rowe ◽

L. R. Ward ◽

E. J. Threlfall

Keyword(s):

Phage Type ◽

Paediatric Hospital ◽

Phage Types ◽

Hospital Outbreak ◽

Group I ◽

Severe Gastroenteritis ◽

Single Clone ◽

Compatibility Group ◽

Resistant Strains

SummaryHospital outbreaks of severe gastroenteritis caused by multi-resistantSalmonellatyphimuriumhave occurred in a number of cities throughout India since 1977. The strains involved belong to phage types 66 or 122, or are untypable; the latter are derived from types 66 or 122 by acquisition of one or more of a number of temperate bacteriophages. Types 66 and 122 are closely related and react with the same phages of theS. typhimuriumtyping scheme.A plasmid belonging to compatibility group FImeencoding resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, sulphonamides, spectinomycin, tetracyclines, gentamicin and trimethoprim (R-type ACKSSuSpTGTm) is present in all of the multi-resistant strains. Several other plasmids have been identified including an SSu resistance determinant, a group I2, transfer factor and an R factor coding for resistance to kanamycin, streptomycin and sulphonamides which is compatible with plasmids of all the standard compatibility groups. These plasmids are only present in a proportion of the strains examined.Examination of strains from other sources has identified a paediatric hospital outbreak in Saudi Arabia and a number of sporadic infections in Great Britain which have been caused by the same organisms. These studies show that, despite differences in phage type and plasmid content, this group of strains belongs to a single clone which has become widespread in India with some extension to other countries.

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Molecular Characterization of an Antibiotic Resistance Gene Cluster of Salmonella typhimuriumDT104

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.43.4.846 ◽

1999 ◽

Vol 43 (4) ◽

pp. 846-849 ◽

Cited By ~ 164

Author(s):

Connie E. Briggs ◽

Pina M. Fratamico

Keyword(s):

Antibiotic Resistance ◽

Salmonella Typhimurium ◽

Resistance Gene ◽

Resistance Genes ◽

Antibiotic Resistance Gene ◽

Phage Type ◽

Antibiotic Resistance Genes ◽

Emerging Pathogen ◽

Resistant Phenotype

ABSTRACT Salmonella typhimurium phage type DT104 has become an important emerging pathogen. Isolates of this phage type often possess resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT resistance). The mechanism by which DT104 has accumulated resistance genes is of interest, since these genes interfere with treatment of DT104 infections and might be horizontally transferred to other bacteria, even to unrelated organisms. Previously, several laboratories have shown that the antibiotic resistance genes of DT104 are chromosomally encoded and involve integrons. The antibiotic resistance genes conferring the ACSSuT-resistant phenotype have been cloned and sequenced. These genes are grouped within two district integrons and intervening plasmid-derived sequences. This sequence is potentially useful for detection of multiresistant DT104.

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Molecular characterization of multiresistant strains ofSalmonella typhifrom South Asia isolated in Ontario, Canada

Canadian Journal of Microbiology ◽

10.1139/w98-012 ◽

1998 ◽

Vol 44 (4) ◽

pp. 356-363 ◽

Cited By ~ 10

Author(s):

N Harnett ◽

S McLeod ◽

Y AuYong ◽

J Wan ◽

S Alexander ◽

...

Keyword(s):

Molecular Weight ◽

South Asia ◽

Antimicrobial Agents ◽

Phage Type ◽

Salmonella Typhi ◽

Mercury Resistance ◽

Temperature Sensitive ◽

K 12 ◽

Multiresistant Strains

Two hundred and fourteen isolates of Salmonella typhi submitted to our laboratory between 1992 and 1996 were tested for susceptibility to 20 antimicrobial agents. Forty-eight of the 214 isolates (22.4%), recovered from individuals who had travelled in South Asia, were multiresistant. Forty-four of the 48 isolates were resistant to ampicillin, chloramphenicol, tetracycline, streptomycin, sulfamethoxazole, trimethoprim, cotrimoxazole, ticarcillin, and piperacillin; the other four isolates were resistant to four to six agents. Forty-two of the multiresistant isolates belonged to Vi phage type E1, two isolates from the Punjab State belonged to phage type A, another from the Punjab State belonged to phage type E3, one isolate from Pakistan belonged to type M1, and one isolate from India belonged to type J1. Plasmids from 45 of 48 isolates showed a temperature-sensitive mechanism of transfer to Escherichia coli K-12 strains, characteristic of HI incompatibility group plasmids. The majority of plasmids had an estimated molecular weight of 120 MDa and encoded both citrate utilization and mercury resistance. Plasmids from three isolates had an estimated molecular weight of 112-115 MDa; one of these isolates encoded citrate utilization but not mercury resistance. Analysis of isolates by pulsed-field gel electrophoresis after digestion with XbaI and SpeI indicated that the majority of multiresistant isolates shared a common restriction profile, while four isolates had unique patterns.Key words: typing, multiresistant, Salmonella typhi.

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