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Cíl práce: Zhodnocení výskytu a charakteristik L. monocytogenes ve vzorcích syrového kravského mléka odebraných na farmách (bazénové vzorky) a z prodejních automatů. Materiál a metody: Průkaz a stanovení počtu bylo provedeno dle ČSN EN/ISO 11290 – 1,2. Kmeny byly typizovány sérotypizací a makrorestrikční analýzou metodou pulzní gelové elektroforézy. Výsledky: Přítomnost L. monocytogenes byla prokázána u 3,2 % (11/346) bazénových vzorků a u 1,8 % (4/219) vzorků syrového kravského mléka z prodejních automatů. Nálezy L. monocytogenes v syrovém mléce měly sporadický charakter, pouze na jedné farmě byly detekovány opakovaně. Z 16 získaných kmenů L. monocytogenes 13 náleželo k sérotypu 1/2a, dva kmeny k sérotypu 1/2b a jeden k sérotypu 4b. Makrorestrikční analýza ukázala značnou heterogenitu profilů, celkem bylo detekováno 9 různých pulzotypů. Nejčastěji byl detekován pulzotyp 711, který byl zjištěn na třech farmách. Závěr: Výskyt L. monocytogenes v syrovém kravském mléce v České republice je relativně nízký. Dosažené výsledky potvrdily, že některé klony L. monocytogenes ze syrového mléka jsou shodné s kmeny izolovanými z potravin a člověka.
Background: To assess current microbiological risks of raw cow's milk. The presented work reports the prevalence of selected bacteria on Czech dairy farms in 2010 and compares the results with a similar study in 2002. Material and methods:The prevalence of bacteria was studied by culture methods using milk filters made from non-woven fabric collected from dairy farms throughout the year 2010. Together 260 filters from 65 dairy farms were tested. The prevalence of Campylobacter spp., Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O 157 and Salmonella spp. in filters was tested. In staphylococci, genes encoding enterotoxin-production were studied. In Campylobacter spp., resistance to antibiotics was ascertained. Results:In 2010, the prevalence rates of selected bacteria on farms were as follows: Campylobacter spp. 3 %, Escherichia coli O 157 0.4 %, Salmonella spp. 0.8 %, Listeria monocytogenes 10 % and Staphylococcus aureus 31 %. In 12 % of the tested filters, S. aureus with the genetic make-up for enterotoxin production was isolated. Antibiotic resistance in Campylobacter spp. isolated from dairy farms is different from that in human or poultry isolates. Conclusion: Raw cow's milk contains bacteria capable of causing human alimentary tract diseases. The above microbiological risks for consumers are eliminated by proper storage conditions (below 10 °C) and heat treatment (boiling) of raw milk.
- Klíčová slova
- zoonóza, alimentární infekce, mléčný filtr, enterotoxin,
- MeSH
- antibiotická rezistence MeSH
- Bacteria izolace a purifikace metabolismus účinky léků MeSH
- bakteriální léková rezistence MeSH
- enterotoxiny biosyntéza MeSH
- mléko mikrobiologie MeSH
- potravinářská mikrobiologie MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Geografické názvy
- Česká republika MeSH
The occurrence of antimicrobial-resistant bacteria is an important public health issue. The aim of this study was the monitoring of resistant Escherichia coli in raw cow's milk with a focus on the detection of extended-spectrum β-lactamase (ESBL)-producing strains. In total, 263 samples of raw milk from 40 farms were collected and investigated in 2010 to 2013 in the Czech Republic. Detection of E. coli was performed and evaluated according to ISO 16649-2, and antibiotic resistance was screened by the disk diffusion method. The presence of E. coli was detected in 243 (92.4%) samples. In total, 270 isolates were obtained. Resistance to β-lactam (31.8%) and tetracycline (13.0%) antibiotics was detected most often and also multiresistant strains (5.5%) were observed. E. coli isolates found to be resistant to β-lactam, tetracycline, and quinolone antibiotics were assayed by PCR to detect selected genes encoding those resistance mechanisms. In isolates in which any bla genes were detected, a double-disk synergy test was performed. ESBL production was confirmed in 2 (0.7%) isolates. The genetic analysis identified the presence of the blaCTX-M gene and other resistance genes (tet(B) and qnrB). Both ESBL-positive isolates originated from the same farm and had an identical pulsed-field gel electrophoresis profile. The findings of our study indicate that milk can be a reservoir of bacteria carrying resistance genes with a potential for spreading through the food chain.
- MeSH
- antibakteriální látky farmakologie MeSH
- beta-laktamasy biosyntéza genetika MeSH
- Escherichia coli účinky léků enzymologie genetika izolace a purifikace MeSH
- mléko mikrobiologie MeSH
- mnohočetná bakteriální léková rezistence genetika MeSH
- polymerázová řetězová reakce MeSH
- proteiny z Escherichia coli genetika MeSH
- pulzní gelová elektroforéza MeSH
- skot MeSH
- syrová strava mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- Listeria monocytogenes imunologie izolace a purifikace MeSH
- Listeria imunologie izolace a purifikace MeSH
- mléko mikrobiologie MeSH
- Geografické názvy
- Turecko MeSH
The aim of this study was to assess the quality of raw cow's milk from an automatic milking system. Samples of milk (48) were analyzed chemically and microbiologically and the somatic cell count, freezing point and inhibitor residues were determined. For comparison purposes, milk analysis data from two farms using conventional machine milking and 2008 milk analysis report data for the Czech Republic were used. All physical and chemical characteristics of the study samples were within the established limits. The average content (%) of chemical indicators was following: fat 3.79 ± 0.18, protein 3.46 ± 0.06, casein 2.67 ± 0.09, lactose 4.82 ± 0.04 and NFS 8.96 ± 0.11. The values for freezing point and somatic cells count were 221 ± 46.103·ml-1 and -0.521 ± 0.003 °C respectively. No inhibitor residue was detected in any of the samples. Microbiological values were lower than the limits: the total microbial count (2.3·104 CFU·ml-1), psychrotrophic count (6.3·103 CFU·ml-1), coliform count (2.4·101 CFU·ml-1), Escherichia coli count (3.2·101 CFU·ml-1), enterococci count (8.5·101 CFU·ml-1) and Staphylococcus aureus count (1.1·101 CFU·ml-1). The study provides a comprehensive view on the quality of milk produced by robotic milking. The automatic milking system seems to be excellent in terms of milking and milk hygiene
- Klíčová slova
- robotické dojení, somatické buňky,
- MeSH
- analýza potravin MeSH
- bezpečnost potravin * MeSH
- lidé MeSH
- mléko * chemie mikrobiologie MeSH
- tranzitní teplota MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
This study describes the prevalence of Encephalitozoon cuniculi in raw cow's milk and evaluates the effect of different milk pasteurization treatments on E. cuniculi infectivity for severe combined immunodeficient (SCID) mice. Using a nested polymerase chain reaction approach, 1 of 50 milking cows was found to repeatedly shed E. cuniculi in its feces and milk. Under experimental conditions, E. cuniculi spores in milk remained infective for SCID mice following pasteurization treatments at 72 °C for 15 s or 85 °C for 5 s. Based on these findings, pasteurized cow's milk should be considered a potential source of E. cuniculi infection in humans.
- MeSH
- Encephalitozoon cuniculi izolace a purifikace patogenita MeSH
- feces parazitologie MeSH
- mléko parazitologie MeSH
- myši SCID MeSH
- myši MeSH
- pasterizace metody MeSH
- polymerázová řetězová reakce MeSH
- skot MeSH
- spory hub izolace a purifikace patogenita MeSH
- vysoká teplota MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- skot MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIMS: Strain-specific detection of Bacillus cereus and Bacillus licheniformis in raw and pasteurized milk, and yoghurt during processing. METHODS AND RESULTS: Randomly selected isolates of Bacillus spp. were subjected to PCR analysis, where single primer targeting to the repetitive sequence Box elements was used to fingerprint the species. The isolates were separated into six different fingerprint patterns. The results show that isolates clustered together at about the 57% similarity level with two main groups at the 82% and 83% similarity levels, respectively. Contamination with identical strains both of B. cereus and B. licheniformis in raw and pasteurized milk was found as well as contaminated with different strains (in the case of raw milk and yoghurt/pasteurized milk and yoghurt). Several BOX types traced in processed milk samples were not discovered in the original raw milk. CONCLUSIONS: BOX-PCR fingerprinting is useful for characterizing Bacillus populations in a dairy environment. It can be used to confirm environmental contamination, eventually clonal transfer of Bacillus strains during the technological processing of milk. SIGNIFICANCE AND IMPACT OF THE STUDY: Despite the limited number of strains analysed, the two Bacillus species yielded adequately detectable banding profiles, permitting differentiation of bacteria at the strain level and showing their diversity throughout dairy processing.
- MeSH
- Bacillus cereus genetika izolace a purifikace MeSH
- Bacillus genetika izolace a purifikace klasifikace MeSH
- DNA fingerprinting metody MeSH
- druhová specificita MeSH
- financování organizované MeSH
- jogurt mikrobiologie MeSH
- kontaminace potravin MeSH
- mlékárenství MeSH
- mléko mikrobiologie MeSH
- polymerázová řetězová reakce MeSH
- průmysl zpracování potravin metody MeSH
- sterilizace MeSH
- techniky typizace bakterií MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Cíl práce: Zhodnocení výskytu a charakteristik L. monocytogenes ve vzorcích syrového kravského mléka odebraných na farmách (bazénové vzorky) a z prodejních automatů. Materiál a metody: Průkaz a stanovení počtu bylo provedeno dle ČSN EN/ISO 11290 – 1,2. Kmeny byly typizovány sérotypizací a makrorestrikční analýzou metodou pulzní gelové elektroforézy. Výsledky: Přítomnost L. monocytogenes byla prokázána u 3,2 % (11/346) bazénových vzorků a u 1,8 % (4/219) vzorků syrového kravského mléka z prodejních automatů. Nálezy L. monocytogenes v syrovém mléce měly sporadický charakter, pouze na jedné farmě byly detekovány opakovaně. Z 16 získaných kmenů L. monocytogenes 13 náleželo k sérotypu 1/2a, dva kmeny k sérotypu 1/2b a jeden k sérotypu 4b. Makrorestrikční analýza ukázala značnou heterogenitu profilů, celkem bylo detekováno 9 různých pulzotypů. Nejčastěji byl detekován pulzotyp 711, který byl zjištěn na třech farmách. Závěr: Výskyt L. monocytogenes v syrovém kravském mléce v České republice je relativně nízký. Dosažené výsledky potvrdily, že některé klony L. monocytogenes ze syrového mléka jsou shodné s kmeny izolovanými z potravin a člověka.
Background: Evaluation of the incidence and characteristics of L. monocytogenes in samples of raw cow´s milk collected on farms (bulk tank milk samples) and from vending machines. Material and methods: Detection of L. monocytogenes and enumeration was carried out according to EN/ISO 11290 – 1,2. Strains were characterised by serotyping and makrorestriction analysis using pulsed field gel electrophoresis. Results: The presence of L. monocytogenes was detected in 3,2% (11/346) of bulk tank milk samples and 1,8% (4/219) samples of raw cow´s milk from vending machines. Findings of L. monocytogenes in raw milk were sporadic, only on one farm strains of L. monocytogenes were detected repeatedly. Thirteen strains of L. monocytogenes belonged to serotype 1/2a, two strains to serotype 1/2b and one to serotype 4b. Macrorestriction analysis revealed considerable heterogeinity of profiles, nine different pulsotypes were detected. Pulsotype 711 was the most frequent. This pulsotype was found on three different farms. Conclusions: The incidence of L. monocytogenes in raw cow´s milk is relatively low in the Czech Republic. The results confirmed that some clones of L. monocytogenes from raw milk are identical with food and human strains.
- Klíčová slova
- listerie, bazénové vzorky mléka, ekologický a konvenční chov, makrorestrikční analýza,
- MeSH
- Listeria monocytogenes izolace a purifikace klasifikace MeSH
- mlékárenství MeSH
- mléko mikrobiologie MeSH
- potravinářská mikrobiologie MeSH
- sérotypizace MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Geografické názvy
- Česká republika MeSH
