Enterococci In Samples Research Articles

Detection of vancomycin-resistant enterococci in samples from broiler flocks and houses in Turkey.

Vancomycin-resistant enterococcus (VRE) is a global threat to public health. Knowledge about the occurrence of vanA-carrying enterococci in broiler and environmental samples is important as antibiotic resistance can be transferred to human bacteria. The aim of this study was to investigate the presence of VRE in broiler cloacal and environmental (house) samples and to genotype the isolates. In this study, 350 swabs were collected from broiler farms. All samples were plated onto enterococcus selective agar containing 6 mg/L vancomycin and 64 mg/L ceftazidime. Minimum inhibitory concentration (MIC) values were determined for vancomycin and teicoplanin. Vancomycin-resistant Enterococcus faecium (VREfm) was isolated from 6 out of 300 (2%) broiler cloacal samples and 13 out of 50 (26%) house samples. All E. faecium isolates had vanA genes. All VREfm isolates (19 isolates) were confirmed to be 95% similar to each other. In conclusion, although 20 years have passed since the ban on avoparcin in Turkey, the present study shows that VREfm isolates are still present in broiler production and especially in broiler houses, and most importantly, a major VREfm clone was isolated from broiler cloacal and house samples.

A comparison of the microbiologic profile of indwelling versus external urinary catheters

We studied the microbiology reports of urine cultures collected from external (condom catheters) versus indwelling (Foley) catheters. The equal prevalence of Enterobacteriaceae and Enterococci in samples from both catheter types calls into question the practice of switching from indwelling to external catheters to decrease catheter-associated bacteriuria.

Faecal indicators and pathogens in selected New Zealand waterfowl

Freshly excreted droppings from Canada geese (n=80), black swans (n=80), ducks (n=80) and gulls (n=80) were collected from sites around New Zealand. The droppings were enumerated for Escherichia coli, enterococci and Salmonella spp., and for the presence/absence of Cryptosporidium spp. Overall prevalence of E. coli and enterococci in samples was 95% and 94%, respectively. Cryptosporidium spp. was detected in 2% of the samples, whereas no Salmonella spp. were detected in the survey. Preliminary estimates of daily microbial outputs suggest that ducks will produce the highest loadings of E. coli and enterococci per bird, whereas Canada geese will produce the highest loadings of Campylobacter spp. per bird. This study provides the first set of indicator and pathogen counts for one of the largest sources of diffuse faecal contamination of natural waters in New Zealand.

Vancomycin Resistance and Antibiotic Susceptibility of Enterococci in Raw Meat

The purpose of this study was to investigate antimicrobial resistance, in particular to vancomycin, of enterococci in samples (100) of meat (beef, chicken, turkey, lamb, and pork) sold in retail outlets of Catanzaro (Italy). Enterococci were identified to the species level. Antimicrobial susceptibility tests for a large spectrum of antibiotics including glycopeptides were performed by the disk diffusion method. Kappa statistic was used to evaluate associations of resistance to vancomycin with other antimicrobials. Enterococci were isolated from 45% of the samples, mostly from chicken meat (65.4%). Overall, 29% of samples were contaminated by vancomycin-resistant enterococci (VRE), whereas among those positive they represented 64.4% of isolates. Higher prevalence of vancomycin resistance was found in chicken samples (76.5%). The overall resistance to teicoplanin (TRE) was 30%, whereas among those positive, TRE represented 66.7% of isolates. The most frequent isolates were Enterococcus faecium (35.6%) and Enterococcus faecalis (33.3%). Resistance to vancomycin and teicoplanin was observed in 75% and 78.5% of E. faecium, and in 40% and 46.7% of E. faecalis, respectively. Most strains were susceptible to ampicillin (80%), while 88.9% were resistant to methicillin. The most effective antimicrobials were imipenem (73.3% susceptible) and rifampin (80%). The highest prevalence of resistance was for streptomycin (88.9%), tetracycline (84.4%), and erythromycin (75.6%). Resistance to vancomycin was significantly associated to methicillin, teicoplanin, erythromycin, tetracycline, and chloramphenicol. Further investigations about enterococcal colonization and infections in community and hospital subjects are needed.

An Improved Method for the Determination of the Most Probable Number of Enterococci in Foods

Azide yeast dextrose-ethyl violet azide citrate broth method (AYD-EAC) for enterococcal test, reported by Horie in 1960, was reviewed and an improved method, AC (37°C) -AC (45°C), was developed in this work.In the new method, azide citrate medium (AC, polypepton, 20g; yeast extract, 5g; dextrose, 5g; Na-citrate·2H2O, 10g; NaCl, 5g; K2HPO4, 4g; KH2PO4, 1.5g; NaN3, 0.25g; distilled water, 1, 000ml) was employed both in presumptive and confirmatory test, respectively. Although the composition of AC medium resembled closely to that of EAC medium used in original method, ethyl violet was not used in the new medium.AC medium tubes inoculated with serial dilutions of the samples were incubated at 37°C for 48±3 hours. Tubes showing turbidity were transfered to fresh tubes of AC medium, using a wire loop (3mm in diameter). After the tubes were incubated for 48±3 hours at 45°C, tubes showing turbidity were considered positive confirmatory test.Using AYD-AC and AC-AC method, MPN values of enterococci in 27 samples of various contaminated waters, raw oyster and frozen foods were determined. It was shown that although MPN values obtained by both methods were comparable, AC medium gave less false positive tubes than AYD medium in presumptive test. Of 188 tubes recorded as positive in confirmatory test of AC-AC method, 187 were found to contain Gram-positive cocci, in pairs or short chains, which grew in 6.5% NaCl containing glucose broth and showed negative catalase test.It was known that AC-AC method was highly specific for the determination of entero-cocci in samples, such as contaminated waters or foods, which contain heterogeneous bacterial flora.

Studies on Enterococci

Enterococci were obtained from 338 samples (71%) of 464 materials of flies and cockroaches. Of these samples examined, enterococcal strains were isolated at high level (87%) from intestinal contents of cockroaches.The bacterial counts of enterococci in samples tested were at the level from 102 to 107 per sample. Of these, enterococcal counts of the bodies (including the intestinal contents) were much more than those of the legs.According to biological properties, the majority of the isolates were identified as Str. faecium (type BII, reported by Shimazaki et al.). Most of the remainders were classified as Str. faecalis and Str. faecalis var. liquefaciens (type AII, the same reporter) and only a few strains showing the beta-haemolysis were detected. Furthermore, some strains among the isolates could not be identified clearly.

On Enterococci in Marketed Animal Foods (Meat, Fish, Milk and their Products)

The authers investigated on the contamination of enterococci in 1700 marketed meat, fish, milk and their products from food hygienic point review and these investigations were performed between 1951 and 1960, and the results were summerized as follows.The contamination rate of enterococci in samples were considerably high, especially remarkable in ground meat, fresh fish and row milk. The contamination degree by enterococci was between 104 and 105 per g. When the number of enterococci was compared with total viable counts and coli-group counts in the same samples, it was found that enterococci was from one over hundred to one over thousand of total viable counts and almost equal to coli-group.In classfing of enterococci strains, 85% of isolated belonged to Str. faecalis, 4.92% to Str. liquefaciens, 1.14% to Str. zymogenes, 1.85% to Str. durans, 6.44% to Unidentified enterococci. 9 out of strains of 218 enterococci isolated from samples were toxic to mice and 6 were enterotoxin producing strains. In the test of heatresistability on 163 strains isolated, whole strains could not survived at 70°C for 30 minutes but 7.8% of strains survived at 65°C for 60 minutes and 48% of stranis survived at 65°C for 30 minutes.