Aquarium pets as a source of antibiotic-resistant salmonellae

1979 ◽  
Vol 25 (4) ◽  
pp. 535-541 ◽  
Author(s):  
T. J. Trust ◽  
Karen H. Bartlett

Thirteen serotypes of Salmonella isolated from imported ornamental aquarium frogs, snails, and their waters were shown to be multi-drug-resistant. Among the resistances exhibited were resistance to gentamicin, sulfamethoxazole–trimethoprim, cephalothin, and nalidixic acid. Frog isolates displayed eight different patterns and snail isolates had two different resistance patterns. The most common serotype, Salmonella typhimurium, was resistant to 18 antibacterials while other salmonellae were resistant to 9 to 16 antibacterials. Resistances in S. typhimurium and S. bovis-morbificans were conjugative and a number of R plasmids participated in the resistance. The plasmid-mediated resistance in S. typhimurium was stable and the levels of resistance conferred were markedly higher than in the other salmonellae tested. Resistance of other serotypes was non-conjugative and resistance to the β-lactam antibiotics was unstable.

1997 ◽  
Vol 60 (8) ◽  
pp. 1001-1005 ◽  
Author(s):  
MARIA A. TESSI ◽  
MARIA S. SALSI ◽  
MARIA I. CAFFER ◽  
MARIA A. MOGUILEVSKY

The antibiotic resistance profiles and transferable R factors of Salmonella and Escherichia coli isolates from 104 broiler carcasses taken from one processing plant were determined. Carcasses were sampled after immersion chilling. All samples were transported iced and immediately analyzed upon arrival to the laboratory. The resistance patterns of isolates to 12 antibiotics were determined (i.e., ampicillin, cephalothin, streptomycin, sulfisoxazole, trim-ethoprim-sulfamethoxazole, nalidixic acid, tetracycline, neomycin, chloramphenicol, gentamicin, colistin, and nitrofurantoin). Isolates resistant to one or more antibiotics were utilized as donors of resistance to completely antibiotic-sensitive strains, an E. coli K-12, F−, J5, azide-resistant strain and a Salmonella serovar Enteritidis. Transfer of the different R plasmids was confirmed by the determination of the resistance patterns of the transconjugants. Of the 93 Salmonella and 71 E. coli strains isolated from these samples, the largest numbers were resistant to tetracycline (52.7% and 49.3%), sulfisoxazole (45.2% and 42.3%), and streptomycin (37.6% and 39.4%). Large percentages of the Salmonella (33.3%) and the E. coli (30.0%) strains transferred all or part of their resistance to E. coli K-12 in mixed cultures. Great variation was observed between different strains in the frequency at which they transferred resistance. Resistance to tetracycline, sulfisoxazole, and streptomycin was found to be conferred by 31.7%, 29.8%, and 21.6% of the 19 R factors identified. No transfer of resistance to nalidixic acid, gentamicin, cephalothin, nitrofurantoin, and chloramphenicol was detected. When 30 antibiotic-resistant E. coli strains were cultured with a sensitive strain of Salmonella serovar Enteritidis,7 (23.3%) of the resistant strains were found capable of transferring R factors. Only 2 (6.7%) of the resistant strains could transfer R factors and unusual β-galactosidase activity.


1986 ◽  
Vol 97 (2) ◽  
pp. 199-204 ◽  
Author(s):  
D. J. Platt ◽  
D. J. Brown ◽  
D. S. Munro

SummaryThe distribution of plasmids was studied in a representative collection of salmonella strains which comprised 98Salmonella typhimuriumand 96 other serotypes. Plasmids were detected in 72% of strains (mean 1·3 plasmids/strain) and individual strains harboured between 0 and 7 plasmids. They were more common amongS. typhimuriumthan other serotypes (incidence 92 and 53%; mean 1·9 and 0·8 plasmids/strain respectively). Although a higher proportion ofS. typhimurium(33%) were antibiotic-resistant compared to other serotypes (14%) the evidence presented indicated that R-plasmids were not responsible for the difference observed in the number and distribution of plasmids in these strains. These results were discussed in comparison with similar studies ofEscherichia coliand other enteric genera.


1981 ◽  
Vol 87 (2) ◽  
pp. 257-269 ◽  
Author(s):  
S. Makino ◽  
N. Ishiguro ◽  
G. Sato ◽  
N. Seno

SummaryA total of 321Salmonella typhimuriumstrains of bovine origin obtained in northern Japan during the period 1970–1979 were tested for drug resistance and detection of conjugative R plasmids. Three hundred and eighteen (99·1 %) of these strains were resistant to one or more drugs. The isolation frequency of multiply drug-resistant strains tended to increase year by year. Two hundred and thirty-seven (74·5%) of these resistant strains carried conjugative R plasmids. A total of 308 R plasmids including 174 (56·5 %) thermosensitive (ts) R plasmids were derived from the 237 drug-resistant strains, indicating that 71 (30·0%) strains have two different conjugative R plasmids in a single host cell. Of the 308 R plasmids examined for fertility inhibition (fi), 167 ts and 131 non-ts R plasmids werefi−. Of the 60 ts R plasmids examined for incompatibility, 50 were classified into H1 group and 10 into H2 group. Of the 52 non-ts R plasmids examined, 35 were classified into the Iα group and the remaining plasmids were untypable in our tests. Mercury resistance marker was found in about 20% of H1 R plasmids coding for multiresistance, and all of H2 R plasmids coded for resistance to tellurite. The clonal distribution of anS. typhimuriumstrain which carried an H1 R plasmid coding for resistance to six drugs and mercury was recognized in 1978 and 1979.


1989 ◽  
Vol 103 (3) ◽  
pp. 513-522 ◽  
Author(s):  
A. A. Ojeniyi

SUMMARYEight hundred and sixty-four Escherichia coli isolates from workers at the University of Ibadan Teaching and Research Poultry Farm, and 216 isolates from poultry attendants at a commercial poultry farm in the city were found to be resistant to streptomycin, sulphafurazole and tetracycline. In contrast, all 576 and 288 E. coli isolates from village fowls and from villagers respectively were sensitive to these drugs. Isolates from birds in a modern university poultry unit (3744) exhibited the same resistance patterns as those isolated from workers who were in direct contact with the birds. No nalidixic acid-resistant E. coli was isolated from farm workers prior to their assignment to the experimental pen. Following experimental oral infection of birds with E. coli K12 J5 NA Lac, the organism was recovered from the workers who manned the experimental pen. Neither before nor after the experimental infection was any nalidixic acid resistant E. coli isolated from workers who manned the pen from which birds used in the experiment were selected. Similarly, no drug resistant organisms were isolated from workers outside the poultry unit of the university or commercial farm. The MIC of the drugs against the avian and human E. coli isolates at the university and commercial poultry farms were similar.


2018 ◽  
Vol 7 (2) ◽  
pp. 1-7
Author(s):  
Waleed Haji Saeed Akreyi ◽  
Samira Younis Yousif ◽  
Mahde Assafi

The emergence of multi-drug resistant (MDR) bacteria has endangered the efficacy of antibiotics treatment of pathogenic bacteria worldwide. The aim of this research was to investigate the incidence of Salmonella enterica serovar Typhi in Duhok city, Iraq. Specimens of blood and stool were recruited from 267 patients. S. Typhi isolates were diagnosed depending on morphology, biochemical and serological tests. S. Typhi isolates were tested for their antibiotic resistance. Multi-drug resistant S. Typhi isolates were conjugated with E. coli HB101. The plasmid profile of transconjugants was investigated. 15/267 (5.6%) S. Typhi isolates were identified. Based on their biochemical tests, S. Typhi isolates were categorized into two biotypes (I, 26.66% and II, 73.33%). Four resistance patterns were observed. The resistant pattern to ampicillin and tetracycline was the higher (46.6%). Conjugation experiment showed that all antibiotic markers were transferred from S. Typhi to E. coli HB101 with a conjugation frequency of (0.38×10-5). 13.3% of the S. Typhi isolates were multi-drug-resistant resistant and had two small plasmids. Transconjugants E. coli acquired the resistance from the multi-drug resistant S. Typhi. Antibiotics treatment of the pathogens could be hindered by the constant rise of multi-drug-resistant. Further studies are needed to study the mobile genetic elements and their contribution to antibiotics resistance.


2020 ◽  
Author(s):  
Weijie Jin ◽  
Weidong Lin ◽  
Qing Feng ◽  
Dashuai Zhang ◽  
Juan Yang ◽  
...  

Abstract Background As mastitis major causing agents, Coagulase-Negative Staphylococci (CNS) and Staphylococcus aureus (SA), are important and their connections are special and worth comparing. The overall aim of this study is to investigate antimicrobial resistance patterns of CNS and SA. Understanding the special characters of staphylococci is essential for finding the precise strategies or directions against them. Results Staphylococci (47.63%) were the commonest pathogens in subclinical mastitis in Jiangsu province. 73.34% and 45.78% of CNS respectively were extensively drug-resistant (XDR) strains and multiple drug-resistant (MDR) strains, mainly resisting penicillin (77.78%) and ceftazidime (55.95%); for SA, 62.52% of them were MDR strains and resistant to penicillin (94.05%) and norfloxacin (58.33%). Notably, 4 CNS were pandrug-resistant (PDR) strains. According to the chi-square test results, we summary and find that SA was more resistant to quinolones (ciprofloxacin, levofloxacin, and norfloxacin) and co-trimoxazole antibiotics than CNS, significantly; on the other hand, CNS were significantly more resistant to lincomycins (clindamycin), macrolides (including erythromycin and clarithromycin), tetracycline, and nitrofurantoin antibiotics than SA,, in total. Resistance genes were detected more frequently in CNS than SA; nearly a third of CNS resit penicillin by β-lactamase coded by blaZ and CNS resist tetracycline mainly by protein pump mechanism. For SA, blaZ was detected out 27.2%, and the other five resistance genes were rare to be found. Conclusion Responding to antibiotics interfering with metabolisms of nucleotide, SA might be more resistant than CNS; while CNS strains are more likely to become mutations to survive under the stress of antibiotics interfering with protein synthesis. These might provide the advantages for CNS to represent like a reservoir of resistance genes for other staphylococci as the previous researches’ assumption.


1997 ◽  
Vol 60 (6) ◽  
pp. 639-643 ◽  
Author(s):  
FUENG-LIN KUO ◽  
JOHN B. CAREY ◽  
STEVEN C. RICKE

The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P < .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P < .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Amit Gaurav ◽  
Varsha Gupta ◽  
Sandeep K. Shrivastava ◽  
Ranjana Pathania

AbstractThe increasing prevalence of antimicrobial resistance has become a global health problem. Acinetobacter baumannii is an important nosocomial pathogen due to its capacity to persist in the hospital environment. It has a high mortality rate and few treatment options. Antibiotic combinations can help to fight multi-drug resistant (MDR) bacterial infections, but they are rarely used in the clinics and mostly unexplored. The interaction between bacteriostatic and bactericidal antibiotics are mostly reported as antagonism based on the results obtained in the susceptible model laboratory strain Escherichia coli. However, in the present study, we report a synergistic interaction between nalidixic acid and tetracycline against clinical multi-drug resistant A. baumannii and E. coli. Here we provide mechanistic insight into this dichotomy. The synergistic combination was studied by checkerboard assay and time-kill curve analysis. We also elucidate the mechanism behind this synergy using several techniques such as fluorescence spectroscopy, flow cytometry, fluorescence microscopy, morphometric analysis, and real-time polymerase chain reaction. Nalidixic acid and tetracycline combination displayed synergy against most of the MDR clinical isolates of A. baumannii and E. coli but not against susceptible isolates. Finally, we demonstrate that this combination is also effective in vivo in an A. baumannii/Caenorhabditis elegans infection model (p < 0.001)


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