scholarly journals A plate diffusion method for detecting fluoroquinolone residues in raw cow’s milk 

2014 ◽  
Vol 32 (No. 3) ◽  
pp. 260-264 ◽  
Author(s):  
P. Navrátilová ◽  
J. Vyhnálková ◽  
L. Vorlová ◽  
J. Jeřábková
Keyword(s):  
Czech Republic ◽  
Antimicrobial Agents ◽  
Raw Materials ◽  
Reference Method ◽  
Coli Strain ◽  
Animal Origin ◽  
Diffusion Method ◽  
The Czech Republic ◽  
E Coli ◽  
Modified Method

The plate diffusion method is a reference method in the Czech Republic for determination of residues of antimicrobial agents in raw materials and foodstuffs of animal origin. A new method using the E. coli strain ATCC 11303 for the detection of fluoroquinolones was introduced in 2008. The aim of this study was to determine the detection capability (CCβ) of this modified method using this E. coli strain for selected fluoroquinolones registered in the Czech Republic for treating diseases in cattle – danofloxacin, marbofloxacin, ciprofloxacin, enrofloxacin, and flumequine. When comparing the maximum residue limits for individual fluoroquinolones and the CCβ values determined, we can state that the method displays very good sensitivity to ciprofloxacin and enrofloxacin (20 and 40 µg/l), marbofloxacin (70 µg/l), and danofloxacin (30 µg/l). The CCβ of the method for flumequine was not found in concentrations ≤ MRL. The method did not display sensitivity to flumequine even in a concentration equal to twelve times the MRL.

scholarly journals Detection of fluoroquinolone residues in milk using Yersinia spp. strains: towards better sensitivity for flumequine determination

2017 ◽  
Vol 61 (4) ◽  
pp. 467-472
Author(s):  
Pavlína Navrátilová ◽  
Jana Vyhnálková ◽  
Lenka Vorlová
Keyword(s):  
Antimicrobial Agents ◽  
Raw Materials ◽  
Animal Origin ◽  
Diffusion Method ◽  
Lower Sensitivity ◽  
Yersinia Ruckeri ◽  
Maximum Residue Limit ◽  
Detection Capability ◽  
E Coli ◽  
Higher Sensitivity

AbstractIntroduction: Plate diffusion methods play an important role in the monitoring system for antimicrobial agents in raw materials and foodstuffs of animal origin. The aim of this work was to select a Yersinia spp. strain for the plate diffusion method based on sensitivity to a fluoroquinolone, namely flumequine. Another aim was to determine the optimal conditions of the method with the selected strain of Yersinia ruckeri CCM 8467 and to determine the detection capability (CCβ) of this method for residues of selected fluoroquinolones in milk.Material and Methods: Optimum method conditions were set: cell concentration in the test agar at the level of 9.105–106 CFU/mL, discs with a diameter of 12.7 mm, Antimicrobial Inhibitor Test Agar with a pH of 6.0, and incubation at 30°C for at least 18 h and up to 24 h.Results: With respect to the maximum residue limit (MRL), the Y. ruckeri plate method demonstrated the lowest sensitivity to flumequine. The CCβ of the method for flumequine was in the concentration of 100 μg/L−1 (twice the MRL). The study also confirmed that the method exhibits very good sensitivity to the other tested fluoroquinolones, which were marbofloxacin (30 μg/L, 0.4 MRL), ciprofloxacin (10 μg/L, 0.1 MRL), and enrofloxacin (20 μg/L, 0.2 MRL), but lower sensitivity to danofloxacin (42 μg/L, 1.4 MRL).Conclusion: The method with the CCM 8467 strain of Y. ruckeri showed a higher sensitivity to flumequine than the method with the ATCC 11303 strain of E. coli.

Prevalence and Characteristics of Escherichia coli Strains Producing Extended-Spectrum β-Lactamases in Slaughtered Animals in the Czech Republic

2013 ◽  
Vol 76 (10) ◽  
pp. 1773-1777 ◽  
Author(s):  
J. BARDOŇ ◽  
V. HUSIČKOVÁ ◽  
M. CHROMÁ ◽  
M. KOLÁŘ
Keyword(s):  
Escherichia Coli ◽  
Czech Republic ◽  
Pathogenic Bacteria ◽  
Raw Materials ◽  
Medical Problem ◽  
Animal Origin ◽  
The Czech Republic ◽  
E Coli ◽  
Extended Spectrum ◽  
Tract Infections

Resistance of bacteria to antibiotics is a global medical problem requiring close cooperation between veterinary and human physicians. Raw materials and foods of animal origin may be not only a source of pathogenic bacteria causing alimentary tract infections but also a source of bacteria with a dangerous extent of resistance to antibiotics, potentially entering the human food chain. This article presents results of the first study in the Czech Republic detecting the presence of Enterobacteriaceae-producing extended-spectrum β-lactamases (ESBLs) in swabs collected in slaughterhouses from surfaces of healthy animal carcasses. In 2012, swabs taken from pig (n = 166) and cattle (n = 140) carcass surfaces were analyzed. In 17% of 53 studied slaughterhouses, ESBL-producing Escherichia coli strains were isolated. ESBLs were found in 11 and 4% of porcine and bovine samples, respectively. Swabs collected from pigs yielded 18 ESBL-producing E. coli strains. The bla genes were found to encode production of CTX-M-1 group enzymes in 16 strains, SHV in one case, and both CTX-M-1–like and TEM in another case. In swabs taken from cattle, five ESBL-producing E. coli strains were isolated. In three cases, the bla genes for CTX-M-1–like production were identified; in two cases, genes for both CTX-M-1–like and TEM production were found. The similarity/identity of ESBL-positive isolates was compared by pulsed-field gel electrophoresis. This is the first report and characterization of the presence and nature of ESBL-producing E. coli in swabs collected from surfaces of healthy pig and cattle carcasses in slaughterhouses in the Czech Republic.

scholarly journals Characterisation of Colistin -Resistant Enterobacterales and Acinetobacter Strains Carrying mcr Genes from Asian Aquaculture Products

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 838
Author(s):  
Alžběta Kalová ◽  
Tereza Gelbíčová ◽  
Søren Overballe-Petersen ◽  
Eva Litrup ◽  
Renáta Karpíšková
Keyword(s):  
Escherichia Coli ◽  
Czech Republic ◽  
Antimicrobial Resistance ◽  
Coli Strain ◽  
Bacterial Strains ◽  
Asian Origin ◽  
The Czech Republic ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Aquaculture Products

Aquaculture systems are widely recognised as hotspots for horizontal gene transfer, and the need for screening for bacteria carrying antimicrobial resistance genes in aquaculture systems is becoming more important. In this study, we characterised seventeen bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and A. nosocomialis) resistant to colistin originating from retailed aquaculture products imported from Vietnam to the Czech Republic. The mcr-1.1 gene was found located on plasmid types IncHI2, IncI2, and IncX4, as well as on the rarely described plasmid types IncFIB-FIC and IncFIB(K), phage-like plasmid p0111, and on the chromosome of E. coli. One E. coli strain carried the mcr-3.5 gene on IncFII(pCoo) plasmid in addition to the mcr-1.1 gene located on IncHI2 plasmid. K. pneumoniae was found to carry the mcr-1.1 and mcr-8.2 genes on IncFIA(HI1) plasmid. The mcr-4.3 gene was found on similar untypeable plasmids of A. baumannii and A. nosocomialis strains, pointing to the possible interspecies transfer of plasmids carrying the mcr-4 gene. Our results highlight that some aquaculture products of Asian origin can represent an important source of variable plasmids carrying mcr genes. The results showed an involvement of phages in the incorporation of the mcr-1 gene into plasmids or the chromosome in E. coli strains from aquaculture. The detection of E. coli with the mcr-1 gene in the chromosome points to the risks associated with the stabilisation of the mcr genes in the bacterial chromosome.

scholarly journals Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

2007 ◽  
Vol 59 (2) ◽  
pp. 508-512 ◽  
Author(s):  
B.R. Paneto ◽  
R.P. Schocken-Iturrino ◽  
C. Macedo ◽  
E. Santo ◽  
J.M. Marin
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Polymerase Chain ◽  
Raw Milk Cheese

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).

scholarly journals Molecular characterisation of antimicrobial resistance and virulence genes in Escherichia coli strains isolated from diarrhoeic and healthy rabbits in Tunisia

2020 ◽  
Vol 28 (2) ◽  
pp. 81
Author(s):  
Raouia Ben Rhouma ◽  
Ahlem Jouini ◽  
Amira Klibi ◽  
Safa Hamrouni ◽  
Aziza Boubaker ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Diffusion Method ◽  
Class 1 Integron ◽  
E Coli ◽  
Class 1

The purpose of this study was to identify <em>Escherichia coli</em> isolates in diarrhoeic and healthy rabbits in Tunisia and characterise their virulence and antibiotic resistance genes. In the 2014-2015 period, 60 faecal samples from diarrhoeic and healthy rabbits were collected from different breeding farms in Tunisia. Susceptibility to 14 antimicrobial agents was tested by disc diffusion method and the mechanisms of gene resistance were evaluated using polymerase chain reaction and sequencing methods. Forty <em>E. coli</em> isolates were recovered in selective media. High frequency of resistance to tetracycline (95%) was detected, followed by different levels of resistance to sulphonamide (72.5%), streptomycin (62.5%), trimethoprim-sulfamethoxazole (60%), nalidixic acid (32.5%), ampicillin (37.5%) and ticarcillin (35%). <em>E. coli</em> strains were susceptible to cefotaxime, ceftazidime and imipenem. Different variants of bla<sub>TEM</sub>, <em>tet</em>, <em>sul</em> genes were detected in most of the strains resistant to ampicillin, tetracycline and sulphonamide, respectively. The presence of class 1 integron was studied in 29 sulphonamide-resistant <em>E. coli</em> strains from which 15 harboured class 1 integron with four different arrangements of gene cassettes, <em>dfrA17</em>+<em>aadA5</em> (n=9), <em>dfrA1</em> + <em>aadA1</em> (n=4), <em>dfrA12</em> + <em>addA2</em> (n=1), <em>dfrA12</em>+<em>orf</em>+<em>addA2</em> (n=1). The <em>qnrB</em> gene was detected in six strains out of 13 quinolone-resistant <em>E. coli</em> strains. Seventeen <em>E. coli</em> isolates from diarrhoeic rabbits harboured the enteropathogenic eae genes associated with different virulence genes tested (<em>fimA</em>, <em>cnf1</em>, <em>aer</em>), and affiliated to B2 (n=8) and D (n=9) phylogroups. Isolated <em>E. coli</em> strains from healthy rabbit were harbouring <em>fim A</em> and/or <em>cnf1</em> genes and affiliated to A and B1 phylogroups. This study showed that <em>E. coli</em> strains from the intestinal tract of rabbits are resistant to the widely prescribed antibiotics in medicine. Therefore, they constitute a reservoir of antimicrobial-resistant genes, which may play a significant role in the spread of antimicrobial resistance. In addition, the eae virulence gene seemed to be implicated in diarrhoea in breeder rabbits in Tunisia.

scholarly journals Detection of virulence genes and antimicrobial resistance profiles of Escherichia coli isolates from raw milk and artisanal cheese in Southern Brazil

2019 ◽  
Vol 40 (1) ◽  
pp. 163 ◽  
Author(s):  
Leandro Parussolo ◽  
Ricardo Antônio Pilegi Sfaciotte ◽  
Karine Andrezza Dalmina ◽  
Fernanda Danielle Melo ◽  
Ubirajara Maciel Costa ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antimicrobial Susceptibility ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Diffusion Method ◽  
Public Health Issue ◽  
Southern Brazil ◽  
E Coli

The serrano artisanal cheese is a typical product from South region of Brazil, which is produced by skilled cheesemakers using raw milk. The contamination of this food by Escherichia coli has a great impact on public health, since it could threat the consumers’ health. The study evaluated the presence of virulence genes, antimicrobial susceptibility profiles and bofilm-production ability of Escherichia coli isolates obtained from raw milk and artisanal cheese produced in Southern Brazil. A total of 117 isolates of E. coli were characterized by multiplex PCR to detect the following virulence genes: eae for enteropatogenic E. coli (EPEC), lt and st for enterotoxigenic E. coli (ETEC), stx for shiga toxin-producing E. coli (STEC), stx and eae for enterohemorrhagic E. coli (EHEC), ipaH for enteroinvasive E. coli (EIEC) and aggR for enteroaggregative E. coli (EAEC). In addition, antimicrobial susceptibility profile to 22 antimicrobial agents was also performed by disk diffusion method, and we searched for extended-spectrum beta-lactamases (ESBL) and/or carbapenemase- producing isolates. Isolates that were positive for ESBL and carbapenemase were further investigated for the presence of the genes: blaTEM, blaSHV, blaOXA, blaCTX-M, for ESBL and blaOXA-48 for carbapenemase. Further, isolates had their ability to form biofilms investigated by the red Congo agar method. Virulence genes of E. coli were identified in 21.37% of the tested isolates, which were classified as EPEC (the most prevalent pathotype) and ETEC or EAEC. Ten (8.55%) of the total studied E. coli isolates revealed a multidrug-resistant profile, since they were resistant to three or more antimicrobial classes; whereas four isolates (3.42%) were classified as ESBL-producers and showed the presence of blaTEM gene. None of the isolates exhibited carbapenemase activity nor did they carry carbapenemase genes. From the total of E. coli isolates, 79 (67.52%) were considered potential biofilm producers. These results address a serious public health issue, since artisanal cheeses pose a risk to consumers’ health, since may be sources of dissemination of diarrheogenic E. coli, that can cause from subclinical to severe and fatal infections in children and adults, and also emphasize the need to improve adaptations/adjustments in the manufacturing processes of these products.

scholarly journals  Faecal shedding of verotoxigenic Escherichia coli in cattle in the Czech Republic

2011 ◽  
Vol 56 (No. 4) ◽  
pp. 149-155 ◽  
Author(s):  
P. Alexa ◽  
L. Konstantinova ◽  
Z. Sramkova-Zajacova
Keyword(s):  
Escherichia Coli ◽  
Czech Republic ◽  
Dairy Cattle ◽  
Age Groups ◽  
Immunomagnetic Separation ◽  
The Other ◽  
Somatic Antigen ◽  
The Czech Republic ◽  
E Coli ◽  
One Year

A survey to estimate the prevalence of verotoxigenic E. coli (VTEC) or enterohaemorrhagic E. coli (EHEC) in rectal swabs from healthy dairy cattle aged three weeks, three months and one year was conducted in three herds from the Czech Republic. Screening for the presence of the stx1, stx2 and eaeA genes in faecal swab cultures was performed by PCR, and in positive samples, isolated colonies were examined. Immunomagnetic separation was used for the isolation of the VTEC serogroup O157 from samples. VTEC were detected in animals from all three herds under study. In the group of 3-week-old calves, VTEC were only detected in samples collected in the summer months. However, in the other age-groups, VTEC were detected in both the summer and winter months. EHEC shedding was observed in 30 to 100% of the total samples collected from cattle aged three months and one year in the summer months, and in 30 to 60% of samples taken in the winter months. EHEC strains of serogroup O157 were detected in two herds. The range of verotoxins shed by VTEC isolates of serogroup O157 differed between herds. Besides serogroup O157, additional EHEC belonging to the antigen groups O26, O103, O128 and O153 have been identified, and in some of them, no somatic antigen was detected.

Experiences in the Field of Radioactive Materials Seizures in the Czech Republic

2007 ◽  
Author(s):  
Karel Svoboda ◽  
Josef Podlaha ◽  
David Sˇi´r ◽  
Josef Mudra
Keyword(s):  
Czech Republic ◽  
Raw Materials ◽  
Nuclear Research ◽  
Municipal Waste ◽  
Radioactive Material ◽  
Radioactive Materials ◽  
Nuclear Research Institute ◽  
The Czech Republic ◽  
Other Information ◽  
Radioactive Sources

In recent years, the amount of radioactive materials seizures (captured radioactive materials) has been rising. It was above all due to newly installed detection facilities that were able to check metallic scrap during its collection in scrap yards or on the entrance to iron-mills, checking municipal waste upon entrance to municipal disposal sites, even incineration plants, or through checking vehicles going through the borders of the Czech Republic. Most cases bore a relationship to secondary raw materials or they were connected to the application of machines and installations made from contaminated metallic materials. However, in accordance to our experience, the number of cases of seizures of materials and devices containing radioactive sources used in the public domain was lower, but not negligible, in the municipal storage yards or incineration plants. Atomic Act No. 18/1997 Coll. will apply to everybody who provides activities leading to exposure, mandatory assurance as high radiation safety as risk of the endangering of life, personal health and environment is as low as reasonably achievable in according to social and economic aspects. Hence, attention on the examination of all cases of the radioactive material seizure based on detection facilities alarm or reasonably grounds suspicion arising from the other information is important. Therefore, a service carried out by group of workers who ensure assessment of captured radioactive materials and eventual retrieval of radioactive sources from the municipal waste has come into existence in the Nuclear Research Institute Rez plc. This service has covered also transport, storage, processing and disposal of found radioactive sources. This service has arisen especially for municipal disposal sites, but later on even other companies took advantage of this service like incineration plants, the State Office for Nuclear Safety, etc. Our experience in the field of ensuring assessment of captured radioactive materials and eventual retrieval of radioactive sources will be presented in the paper.

scholarly journals Frequency of Detection ofEscherichia coli,Salmonellaspp., andCampylobacterspp. in the Faeces of Wild Rats (Rattusspp.) in Trinidad and Tobago

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Comfort Nkogwe ◽  
Juliah Raletobana ◽  
Alva Stewart-Johnson ◽  
Sharianne Suepaul ◽  
Abiodun Adesiyun
Keyword(s):  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Macconkey Agar ◽  
Disc Diffusion Method ◽  
O157 Strain ◽  
E Coli ◽  
Faecal Samples ◽  
Wild Rats

The study was conducted to determine the frequency of isolation ofSalmonella,CampylobacterandE. coliO157 in the faecal samples of rats trapped across the regional corporations in Trinidad and to assess their resistance to antimicrobial agents. A total of 204 rats were trapped for the detection of selected bacteria. Standard methods were used to isolateSalmonella,CampylobacterandE. coliO157. Characterization ofE. coliwas done on sorbitol MacConkey agar to determine non-sorbitol fermentation, blood agar to determine haemolytic and mucoid colonies and by usingE. coliO157 antiserum to determine O157 strain. The disc diffusion method was used to determine resistance to nine antimicrobial agents. Of the 204 rats, 4 (2.0%), 7 (3.4%) and 171 (83.8%) were positive forSalmonellaspp.,Campylobacterspp. andE. coli, respectively. Of the 171 isolates ofE. colitested 0 (0.0%), 25 (14.6%) and 19 (11.1%) were haemolytic, mucoid and non-sorbitol fermenters, respectively. All isolates were negative for the O157 strain. The frequency of resistance to the 9 antimicrobial agents tested was 75% (3 of 4) forSalmonella, 85.7% (6 of 7) ofCampylobacterspp. and 36.3% (62 of 171) forE. coli(;χ2).

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