Antimicrobial Susceptibilities of Salmonella Isolates Obtained from Layer Chicken Houses on a Commercial Egg-Producing Farm in Japan, 1997 to 2002

2005 ◽  
Vol 68 (10) ◽  
pp. 2030-2034 ◽  
Author(s):  
AZUSA SOMEYA ◽  
KOICHI OTSUKI ◽  
TOSHIYUKI MURASE

Susceptibility to antimicrobial agents was examined for 325 isolates of Salmonella enterica serotypes Cerro, Infantis, Livingstone, and Montevideo isolated from layer houses on a commercial egg-production farm in the western region of Japan between 1997 and 2002. No antimicrobials were used for therapeutic purposes on the farm during this period. From 1.8 to 3.1% of the isolates were resistant to ampicillin, chloramphenicol, and tetracycline. Resistance to streptomycin and sulfisoxazole was found in 52.9 and 65.5%, respectively, of Salmonella Montevideo isolates and in 0 to 13.2% of the isolates of the other serotypes. All the streptomycin-resistant isolates of Salmonella Montevideo also exhibited resistance to sulfisoxazole. Salmonella Montevideo isolates were first isolated in 1998, and 80.0% of the isolates obtained in this year were resistant to streptomycin and sulfisoxazole. The results suggest that Salmonella Montevideo isolates that had already acquired resistance may have been introduced into the layer houses, although the route and vehicle of transmission were uncertain. The proportion of Salmonella Montevideo isolates resistant to streptomycin and sulfisoxazole significantly decreased (P < 0.01) from 79.5% for 1998 through 1999 to 37.3% for 2000 through 2002. This decrease probably was due to the fact that no antimicrobials were used on the farm. Among 10 isolates from different serotypes obtained from 1997 to 2002 that were resistant to ampicillin, two and five isolates harbored 42- and 63-kb R plasmids and identical DraI restriction enzyme digest patterns, respectively, and carried the blaTEM gene. The results suggest that the ampicillin resistance determinants were transferred among different serotypes of Salmonella in the layer houses.

2004 ◽  
Vol 133 (1) ◽  
pp. 81-86 ◽  
Author(s):  
C. S. TORO ◽  
M. FARFÁN ◽  
I. CONTRERAS ◽  
O. FLORES ◽  
N. NAVARRO ◽  
...  

A total of 162 clinical isolates of Shigella collected from children in a semi-rural community of Chile were examined for the presence of genetic determinants of resistance to ampicillin, chloramphenicol, tetracycline, and trimethoprim. Ampicillin resistance was most frequently associated with the presence of blaOXA in S. flexneri and with blaTEM in S. sonnei. The blaOXA gene but not blaTEM was located in class 1 integrons. The dhfrIa gene encoding for resistance to trimethoprim was associated to class 2 integrons and detected exclusively in S. flexneri, whereas dhfrIIIc was found in all S. sonnei strains and in 10% of the S. flexneri isolates. Cat, coding for choramphenicol resistance, and blaOXA genes were located in the chromosome in all cases, whereas tetA gene, coding for tetracycline resistance, and blaTEM, dhfrIa and dhfrIIIc genes were found either in the chromosome or in conjugative plasmids. Our results show a heterogenous distribution of antibiotic-resistance determinants between S. flexneri and S. sonnei.


2020 ◽  
Vol 8 (8) ◽  
pp. 1240
Author(s):  
Sangjukta Roy ◽  
Meiji Soe Aung ◽  
Shyamal Kumar Paul ◽  
Salma Ahmed ◽  
Nazia Haque ◽  
...  

Enterococcus faecalis is one of the major causes of urinary tract infection, showing acquired resistance to various classes of antimicrobials. The objective of this study was to determine the prevalence of drug resistance and its genetic determinants for E. faecalis clinical isolates in north-central Bangladesh. Among a total of 210 E. faecalis isolates, isolated from urine, the resistance rates to erythromycin, levofloxacin, and gentamicin (high level) were 85.2, 45.7, and 11.4%, respectively, while no isolates were resistant to ampicillin, vancomycin and teicoplanin. The most prevalent resistance gene was erm(B) (97%), and any of the four genes encoding aminoglycoside modifying enzyme (AME) were detected in 99 isolates (47%). The AME gene aac(6′)-Ie-aph(2”)-Ia was detected in 46 isolates (21.9%) and was diverse in terms of IS256-flanking patterns, which were associated with resistance level to gentamicin. Tetracycline resistance was ascribable to tet(M) (61%) and tet(L) (38%), and mutations in the quinolone resistance-determining region of both GyrA and ParC were identified in 44% of isolates. Five isolates (2.4%) exhibited non-susceptibility to linezolide (MIC, 4 μg/mL), and harbored the oxazolidinone resistance gene optrA, which was located in a novel genetic cluster containing the phenicol exporter gene fexA. The optrA-positive isolates belonged to ST59, ST902, and ST917 (CC59), while common lineages of other multiple drug-resistant isolates were ST6, ST28, CC16, and CC116. The present study first revealed the prevalence of drug resistance determinants of E. faecalis and their genetic profiles in Bangladesh.


mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Louis B. Rice

ABSTRACT Enterococcus faecalis differs from many other common human pathogens in its physiology and in its susceptibility to antimicrobial agents. Multiresistant E. faecalis strains owe their phenotypes to a combination of intrinsic and acquired antimicrobial resistance determinants. Acquired resistance is due to E. faecalis frequenting multicultural environments, its capacity to mate with different species, and the nullification of its own defense mechanisms in some lineages. Intrinsic resistance is a complex phenomenon that is intimately tied to the physiology of the species. In their recent study in mBio, Gilmore and colleagues (M. S. Gilmore, R. Salamzade, E. Selleck, N. Bryan, et al., mBio 11:e02962-20, 2020, https://doi.org/10.1128/mBio.02962-20) use functional genomics to explore the genetic underpinnings of E. faecalis physiology and antimicrobial resistance. While they do not come up with many definitive answers, their work points the way toward new and fruitful areas of investigation.


2018 ◽  
Vol 22 (2) ◽  
pp. 297-300
Author(s):  
V.V. Nevmerzhitsky ◽  
V.Yu. Ivannik ◽  
V.V. Kazmirchuk ◽  
T.N. Moiseenko ◽  
T.A. Volkov ◽  
...  

The fight against staphylococcal infection, increasing the effectiveness of methods of prevention and treatment of diseases of staphylococcal etiology is of interest to scientists and practitioners, both in Ukraine and around the world. The urgency of this problem is growing rapidly, as there is a tendency to increase the resistance of not only staphylococci, but also other gram-positive bacteria. The spread of methicillin-resistant staphylococci restricts the choice of antibiotics for the treatment of diseases of staphylococcal etiology. Staphylococcus aureus is the most common and dangerous type, which is one of the main factors of purulent-inflammatory lesions of the skin and mucous membranes. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. One of the unique and promising medicinal plants, which contains a rich complex of biologically active substances (BAS), is common hops (Humulus lupulus L.). The complex of BAS (flavonoids, hormones, vitamins, bitter, phenolic compounds, essential oils) causes anti-inflammatory, bactericidal, hyposensitizing and analgesic action of hops. The purpose of this work is to determine the antistaphylococcal activity of the carbon dioxide extract of hops and to justify the development on its basis of new antimicrobial agents for the prevention and treatment of infectious and purulent-inflammatory diseases. The following methods were used: microbiological (method of diffusion into agar (well method)) and mathematical and statistical. The high antimicrobial activity of the carbon dioxide extract of hops has been established for museum test strains of the genus Staphylococcus. The results of the studies testify to the prospects of further study of the bactericidal properties of the extract of hops carbon dioxide with the aim of creating effective antimicrobial agents on its basis for the prevention and treatment of infectious and purulent-inflammatory diseases of staphylococcal etiology.


Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 65
Author(s):  
Armin Tarrah ◽  
Shadi Pakroo ◽  
Viviana Corich ◽  
Alessio Giacomini

The existence of antibiotic-resistant bacteria in food products, particularly those carrying acquired resistance genes, has increased concerns about the transmission of these genes from beneficial microbes to human pathogens. In this study, we evaluated the antibiotic resistance-susceptibility patterns of 16 antibiotics in eight S. thermophilus strains, whose genome sequence is available, using phenotypic and genomic approaches. The minimal inhibitory concentration values collected revealed intermediate resistance to aminoglycosides, whereas susceptibility was detected for different classes of β-lactams, quinolones, glycopeptide, macrolides, and sulfonamides in all strains. A high tetracycline resistance level has been detected in strain M17PTZA496, whose genome analysis indicated the presence of the tet(S) gene and the multidrug and toxic compound extrusion (MATE) family efflux pump. Moreover, an in-depth genomic analysis revealed genomic islands and an integrative and mobilizable element (IME) in the proximity of the gene tet(S). However, despite the presence of a prophage, genomic islands, and IME, no horizontal gene transfer was detected to Lactobacillus delbrueckii subsp. lactis DSM 20355 and Lactobacillusrhamnosus GG during 24 h of skim milk fermentation, 2 weeks of refrigerated storage, and 4 h of simulated gastrointestinal transit.


1982 ◽  
Vol 60 (12) ◽  
pp. 1143-1147 ◽  
Author(s):  
Harry W. Duckworth ◽  
Alexander W. Bell

Starting with a colicin E1 resistance recombinant plasmid which contains gltA, the gene for citrate synthase in Escherichia coli, we have constructed an ampicillin-resistance plasmid containing the gltA region as a 2.9-kilobase-pair insert in the tetracycline-resistance region of pBR322. Escherichia coli HB101 harbouring this plasmid, when grown on rich medium containing ampicillin, contains citrate synthase as about 8% of its soluble protein. The enzyme has been purified from this rich source and is identical to the chromosomal enzyme prepared previously in every property tested, except for specific activity, which is 64 U∙mg−1 as compared with 45–50 U∙mg−1 previously obtained. The N-terminal sequences of both enzymes are reported, and they are identical up to residue 16 at least. The overall yield of pure enzyme, starting with the cells grown in 15 L of medium, is 600–800 mg.


2007 ◽  
Vol 51 (11) ◽  
pp. 4062-4070 ◽  
Author(s):  
B. Henrichfreise ◽  
I. Wiegand ◽  
W. Pfister ◽  
B. Wiedemann

ABSTRACT In this study, we analyzed the mechanisms of multiresistance for 22 clinical multiresistant and clonally different Pseudomonas aeruginosa strains from Germany. Twelve and 10 strains originated from cystic fibrosis (CF) and non-CF patients, respectively. Overproduction of the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM was studied. Furthermore, loss of OprD, alterations in type II topoisomerases, AmpC overproduction, and the presence of 25 acquired resistance determinants were investigated. The presence of a hypermutation phenotype was also taken into account. Besides modifications in GyrA (91%), the most frequent mechanisms of resistance were MexXY-OprM overproduction (82%), OprD loss (82%), and AmpC overproduction (73%). Clear differences between strains from CF and non-CF patients were found: numerous genes coding for aminoglycoside-modifying enzymes and located, partially in combination with β-lactamase genes, in class 1 integrons were found only in strains from non-CF patients. Furthermore, multiple modifications in type II topoisomerases conferring high quinolone resistance levels and overexpression of MexAB-OprM were exclusively detected in multiresistant strains from non-CF patients. Correlations of the detected phenotypes and resistance mechanisms revealed a great impact of efflux pump overproduction on multiresistance in P. aeruginosa. Confirming previous studies, we found that additional, unknown chromosomally mediated resistance mechanisms remain to be determined. In our study, 11 out of 12 strains and 3 out of 10 strains from CF patients and non-CF patients, respectively, were hypermutable. This extremely high proportion of mutator strains should be taken into consideration for the treatment of multiresistant P. aeruginosa.


2007 ◽  
Vol 73 (20) ◽  
pp. 6566-6576 ◽  
Author(s):  
Moussa S. Diarra ◽  
Fred G. Silversides ◽  
Fatoumata Diarrassouba ◽  
Jane Pritchard ◽  
Luke Masson ◽  
...  

ABSTRACT The effects of feed supplementation with the approved antimicrobial agents bambermycin, penicillin, salinomycin, and bacitracin or a combination of salinomycin plus bacitracin were evaluated for the incidence and distribution of antibiotic resistance in 197 commensal Escherichia coli isolates from broiler chickens over 35 days. All isolates showed some degree of multiple antibiotic resistance. Resistance to tetracycline (68.5%), amoxicillin (61.4%), ceftiofur (51.3%), spectinomycin (47.2%), and sulfonamides (42%) was most frequent. The levels of resistance to streptomycin, chloramphenicol, and gentamicin were 33.5, 35.5, and 25.3%, respectively. The overall resistance levels decreased from day 7 to day 35 (P < 0.001). Comparing treatments, the levels of resistance to ceftiofur, spectinomycin, and gentamicin (except for resistance to bacitracin treatment) were significantly higher in isolates from chickens receiving feed supplemented with salinomycin than from the other feeds (P < 0.001). Using a DNA microarray analysis capable of detecting commonly found antimicrobial resistance genes, we characterized 104 tetracycline-resistant E. coli isolates from 7- to 28-day-old chickens fed different growth promoters. Results showed a decrease in the incidence of isolates harboring tet(B), bla TEM, sulI, and aadA and class 1 integron from days 7 to 35 (P < 0.01). Of the 84 tetracycline-ceftiofur-resistant E. coli isolates, 76 (90.5%) were positive for bla CMY-2. The proportions of isolates positive for sulI, aadA, and integron class 1 were significantly higher in salinomycin-treated chickens than in the control or other treatment groups (P < 0.05). These data demonstrate that multiantibiotic-resistant E. coli isolates can be found in broiler chickens regardless of the antimicrobial growth promoters used. However, the phenotype and the distribution of resistance determinants in E. coli can be modulated by feed supplementation with some of the antimicrobial agents used in broiler chicken production.


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