Properties of Staphylococcus aureus strains from food processing staff.

AIM: The food processing staff may act as a reservoir of virulent strains of Staphylococcus aureus and contribute to their transmission to foods. The aim of this study was to assess the occurrence and properties of S. aureus in cheese factory staff. MATERIAL AND METHODS: Throat and hand swabs collected from the staff of three different cheese factories were tested. The obtained isolates were characterized on the basis of detection of virulence factors, antimicrobial resistance testing, spa typing, and macrorestriction analysis. RESULTS: S. aureus was detected in 58% of the hand swab samples (7/12) and in 47% (17/36) of the throat swab samples. No methicillin-resistant S. aureus was detected in the throat or on the hands of the food processing staff. Strains carrying genes responsible for the production of enterotoxins (58%) and/or toxic shock syndrome toxin (25%) were recovered from employees of all three premises. One throat swab isolate was positive for the gene encoding production of exfoliatin A. There was no clonal relationship between S. aureus strains isolated from the throat and hands, which suggests possible contamination of the employees' hands arising from the manufacturing environment. CONCLUSION: Good compliance with hygiene guidelines (washing and disinfecting hands and the environment regularly, using gloves and masks, etc.) is a necessary tool for reducing the risk of S. aureus spread by the employees working in the food industry.

Virulence and antibiotic resistance genes in Campylobacter spp. in the Czech Republic.

OBJECTIVE: Thermotolerant species of the genus Campy-lobacter are the important agents causing human foodborne infections throughout the world. The aims of this study were to evaluate the presence of nine putative virulence genes in Campylobacter spp. isolated from patients and from foods (poultry meat, pork liver), to determine the resistance of Campylobacter isolates to eight antibiotic agents and to detect four resistance genes.Matherial and methods: The presence of the virulence genes cdtA, cdtB, cdtC, virB11, ciaB, wlaN, iam, dnaJ and racR was detected by polymerase chain reaction (PCR) in 94 Campylobacter spp. isolates from humans and 123 campylobacters from foods. The phenotypic resistance to selected antimicrobial agents was tested with microdilution method in 82 human isolates and 91 food isolates. The isolates with antibiograms were tested for the presence of blaOXA-61, tet(O), aph-3-1 and cmeB genes by PCR with specific primers. RESULTS: In both human and food C. jejuni isolates the preva-lence of the studied virulence genes, especially dnaJ, racR, ciaB genes and the toxigenic genes cdtA, cdtB, cdtC, was considerably higher than in C. coli isolates. The only exception was the iam gene identified in only C. coli. The tested isolates of both C. jejuni and C. coli were highly resistant to quinolone antibiotics. Additionally, C. coli was also more resistant to erythromycin, streptomycin and, in case of isolates from pork liver, to tetracycline. High prevalence rates of genes encoding antibiotic resistance was noted for the blaOXA-61 and tet(O) genes in both Campylobacter species. CONCLUSIONS: The presented study is the first to assess the presence of genes for virulence and resistance to antibiotics in thermotolerant Campylobacter spp. isolated from humans and foods in the Czech Republic. The resistance of Campylobacter isolates to eight antibiotic agents was also assessed. The prevalence of genes responsible for virulence and resistance is rather varied in thermotolerant Campylobacter spp.

[Occurrence and characteristic of Staphylococcus aureus in pork meat]. / Výskyt a vlastnosti baktérií Staphylococcus aureus ve veprovém mase.

This study was conducted to evaluate the contamination of raw pork meat with Staphylococcus aureus in retail market and their ability to participate in the creation of foodborne intoxication. Strains were characterized by genotypic traits. Of the 197 samples examined 43 (21.8%) were found to be positive for the presence of S. aureus. Toxigennic properties were found in 21 (48.8%) isolates, the major enterotoxigennic gene found was seh (81%). All the S. aureus isolates were screened for resistance to antimicrobial agents by disk diffusion method and for mecA gene encoding resistance to meticillin. Two of the strains isolated in this study harboured the mecA gene (MRSA). The determination of sequence type 398 (ST398) has been confirmed in both MRSA isolates.

[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.

An outbreak of human salmonellosis caused by ampicillin-resistant Salmonella enterica serovar Enteritidis PT13 in the Czech Republic.

In summer 2004, an outbreak caused by Salmonella enterica serovar Enteritidis phage type 13 (S. Enteritidis PT13) was recorded in the Czech Republic. As well being a relatively rare phage type the strain was also ampicillin resistant. Outbreak (n=39) and pre-outbreak isolates (n=13) were characterized by pulsed-field gel electrophoresis (PFGE), beta-lactamase gene polymerase chain reaction and plasmid profile. The majority of outbreak isolates (n=37) were identical in XbaI PFGE profile, and two other outbreak isolates each differed from this profile by one or two fragments respectively. The pre-outbreak isolates were uniform in PFGE profile but distinct from the outbreak strain. Ampicillin resistance was confirmed to be encoded by the blaTEM gene located on the TnA transposon. This gene was readily transferable to a S. Enteritidis recipient strain and was associated with the transfer of a 200-kb plasmid. Our results indicate that all S. Enteritidis PT13 tested from 2004 belonged to a single outbreak strain which prior to 2004 had not been recognized in the Czech Republic.

Characterization of Salmonella enterica serotype typhimurium in the Czech Republic: phage types, antimicrobial and plasmid profiles.

In this study a collection of 547 S. Typhimurium strains isolated in the years 2000 and 2001 both of the human and non-human origin were analysed. 21 different phage types were detected, the most frequent one was DT104 (46%) followed by DT141 (28%) and DT68 (3%). Resistance to one or more antimicrobial agents was found mainly in DT104 (77.4%). S. Typhimurium isolates resistant to 5 and more antimicrobial agents were found in three phagetypes DT104 (57%), DT120 and DT155. Plasmid profiling of DT104 isolates showed 10 different profiles. Pattern A found in 30.5% of tested strains was predominant and carried serovar specific plasmid and one additional small plasmid of approx. 2.5 kb.

Evolution of antibiotic resistance in Salmonella enterica serovar typhimurium strains isolated in the Czech Republic between 1984 and 2002.

In a collection of 66 Salmonella enterica serovar Typhimurium strains isolated between 1984 and 2002 in the Czech Republic, genes coding for antibiotic resistance were determined by using specific PCRs. We found that the pentadrug-resistant ACSSuT clone first appeared in the Czech Republic in 1990. A new variant of the aadA gene designated aadA21 is described, the 5' end of which was identical to aadA2 and the 3' end of which was identical to aadA1.