[Prevalence and characteristics of thermotolerant Campylobacter spp. in the human food chain]. / Výskyt a charakteristika termotolerantních kampylobakteru v potravinovém retezci cloveka.

OBJECTIVES: To monitor the prevalence of Campylobacter spp. in poultry in slaughterhouses, poultry and pork liver at retail, and cows milk in Moravia. To determine the resistance of animal isolates to selected antibiotics; and to compare it with an antibiogram of human strains. MATERIAL AND METHODS: Throughout the year 2013, the following samples were collected in the South Moravian and Olomouc Regions: mixed samples of broiler cecal contents in slaughterhouses, fresh and frozen chickens and pork liver at retail, and raw cows milk from vending machines. The samples were both qualitatively and quantitatively analyzed for the presence of Campylobacter spp. The isolates recovered were tested for resistance to antibiotics. For comparison, antimicrobial resistance was also studied in human isolates from the same regions. RESULTS: A total of 41.8% of the tested food samples were found to contain Campylobacter spp.. The most contaminated (73.2%) were fresh chickens. Campylobacter spp. were not detected in raw cows milk samples. The isolates showed high levels of resistance to quinolone antibiotics and, in the case of C. coli, also to tetracycline and streptomycin. CONCLUSION: The studied commodities were frequently contaminated with Campylobacter spp. The levels of contamination (in CFU/g) varied between commodities and so, evidently, did the real risk for human infections. When antibiotic therapy is needed, quinolone antibiotics cannot be used. Adherence to high standards of consumer safe food handling is crucial for the prevention of diseases.

Prevalence and characteristics of Escherichia coli strains producing extended-spectrum ß -lactamases in slaughtered animals in the Czech Republic.

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 b -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.

[Rapid identification of ESBL--positive clinical samples using real-time PCR method]. / Rychlá identifikace ESBL-pozitivních klinických vzorku metodou real-time PCR.

OBJECTIVES: A new method has been developed for detecting genes determining the extended-spectrum beta-lactamase (ESBL) phenotype directly from patients' clinical material. The method enables detection of the bla(CTX-M) gene encoding CTX-M beta-lactamases and the bla(SHV) gene variants with real-time PCR technology using locked nucleic acid oligonucleotides. MATERIAL AND METHODS: In this pilot study, tracheal aspirates obtained from patients with mechanical ventilation hospitalized at Department of Anaesthesiology and Resuscitation of the University Hospital in Olomouc between 1st March and 30th December 2010 period were tested. Each sample was identified with standard microbiological procedures including phenotypic determination of ESBL-positive enterobacteria. At the same time, each sample was analyzed for the presence of nucleic acids (DNA) which encode CTX-M and SHV ESBL using real-time PCR. RESULTS: 150 samples of tracheal aspirates from 71 patients were included into testing. In the set, 13 (8.7%) ESBL-positive samples were identified by culture methods while 27 (18 %) positive samples were identified by the real-time PCR method. Of the 27 PCR-positive samples, 24 were positive for the bla(CTX) gene; in 2 samples, the ESBL bla(SHV) gene was detected, and both genes were present in 1 sample. All culture-positive samples were also PCR-positive for the presence of bla(CTX) and/or bla(SHV) sequences. CONCLUSIONS: The new real-time PCR assay is likely to shorten the time for detection of enterobacteria producing SHV and CTX-M beta-lactamases from 48 to 6 hours. It enables ESBL-positive enterobacteria determination in tracheal aspirates of patients suffered from life-threatening nosocomial pneumonia where the early introduction of adequate antimicrobial treatment plays the important role.

[Presence of qnr genes in ESBL-positive isolates of Klebsiella pneumoniae]. / Výskyt qnr genu u ESBL-pozitivních izolátu Klebsiella pneumoniae.

OBJECTIVE: The study aimed at determining the presence of qnr genes in ESBL-positive strains of Klebsiella pneumoniae isolated from clinical material obtained from patients hospitalized in several intensive care units in the University Hospital Olomouc. MATERIAL AND METHODS: The study comprised 100 ESBL-producing Klebsiella pneumoniae isolates from clinical samples obtained from patients hospitalized between 1 January 2008 and 31 January 2011. blaTEM, blaSHV, blaCTX-M and qnr genes were detected by polymerase chain reaction (PCR). To compare the similarity or identity of the isolates, pulsed-field gel electrophoresis (PFGE) of DNA fragments was used. RESULTS AND CONCLUSION: The blaSHV gene was detected in 99 from 100 isolates of Klebsiella pneumoniae, which is in accordance with the published data that suppose the chromosomal position of the blaSHV-1 gene in this species. The blaCTX-M gene was detected in 77 isolates. The qnr genes were revealed in 56 isolates and majority (76.8 %) of these qnr-positive bacteria carried also the genes encoding the beta-lactamases CTX-M and TEM. In all cases, the qnrB variant was detected. Plasmids from nine different incompatibility groups were identified, in most cases from the IncFII group (52 isolates). Antibiotic susceptibility tests revealed high frequency of resistance not only to beta-lactams, but also to aminoglycosides, tetracycline and sulfamethoxazole/trimethoprim. PFGE detected 65 different strains and several groups of isolates with the same restriction profile. Although the clinical significance of the qnr genes is not well established, their presence in ESBL-positive Enterobacteriaceae is not negligible and it should be kept in mind.

[Detection of ESBL-positive strains of Escherichia coli in pigs in the Czech Republic]. / Záchyt ESBL-pozitivních kmenu Escherichia coli u prasat v Ceské republice.

BACKGROUND: The goals of the presented regional study were monitoring the prevalence of Enterobacteriaceae producing broad-spectrum beta-lactamases in slaughter pigs and their basic molecular biology analysis. MATERIAL AND METHODS: In the presented study, rectal swabs from 118 slaughter pigs from 5 farms in the Olomouc Region were analyzed. Bacteriological tests aimed at detection and identification of bacteria from the Enterobacteriaceae family producing broad-spectrum beta-lactamases. Suspected isolates were further analyzed using both phenotypic and genotypic methods. RESULTS: From the group of 118 analyzed samples, seven Escherichia coli strains with the presence of the bla genes encoding CTX-M-1 beta-lactamases were isolated. Genes for TEM and SHV enzymes were not detected. This is the first report of ESBL-positive isolates of Escherichia coli in pigs in the Czech Republic.

Growth strategy of the pathogenic yeast Cryptococcus neoformans submerged culture under different cultivation formats.

Growth patterns of Cryptococcus neoformans submerged culture in different culture volumes, intensity of agitation and types of sealing were evaluated to better understand the physiological role of hypoxia response in this yeast. When low intensity agitation was set at high culture volumes and air exchange between the cultivation vessel and external environment was not abolished completely, the cells proliferated slowly but steadily. On the other hand, when the intensity of agitation was high but the vessel was withheld from fresh air supply, the cells first proliferated rapidly, then arrested completely and finally died. Therefore, the central strategy of C. neoformans here seems to lie in its proliferation-rate adjustment to the available oxygen levels and not in its capacity to survive under anoxia. The data support the opinion that the cultures grown under limited aeration (even though not completely withheld from fresh air supply) are much closer to the real cryptococcal life in human tissues than conventional well-aerated exponential cultures.