scholarly journals Biotype characterization of Staphylococcus aureus from milk and dairy products of private production in the western regions of Ukraine

2017 ◽  
Vol 8 (3) ◽  
pp. 384-388 ◽  
Author(s):  
M. D. Kukhtyn ◽  
Y. V. Horyuk ◽  
V. V. Horyuk ◽  
T. Y. Yaroshenko ◽  
O. I. Vichko ◽  
...  

Prevention of foodborne diseases is a priority for the world health system. In the process of manufacturing milk and dairy products, the most important factor endangering their safety is seeding with a conditionally pathogenic and pathogenic microflora. Salmonella, Escherichia coli, Listeria and other microorganisms that reproduce in dairy products without changing their organoleptic properties are a particular danger. Staphylococcus aureus is an opportunistic, conditionally pathogenic microorganism that often contaminates raw milk and dairy products. The aim of the research presented in this article was to determine the dissemination of S. aureus in milk and milk products of household production in the western regions of Ukraine, to identify the biotypes of S. aureus, production of enterotoxins and the presence of methicillin-resistant strains. S. aureus was isolated on BD Baird-Parker Agar. The biotypes of S. aureus were determined according to Meer. The determination of MRSA was carried out on the chromogenic Agar chromID MRSA ("Biomerioux", Russia). The mecA gene was determined using the LightCycler MRSA Advanced Test with LightCycler 2.0 primer (Roche Molecular Biochemicals, Germany). To determine staphylococcal enterotoxins, the test system RIDASCREENSET A, B, C, D, E (R-Biopharm AG, Darmstadt, Germany) was used. We isolated saprophyte staphylococci from milk of raw and dairy products in western regions of Ukraine in 82.7–97.4% of samples. S. aureus is much more rarely isolated from these dairy products, so it was isolated from sour cream at 62.8 ± 0.9%, from milk at 35.5 ± 1.3% and cottage cheese at 23.0 ± 1.6%. Of the most well0known biotypes of S. aureus present in milk of raw and dairy products of domestic production, two ecological types were distinguished: human and cattle. In this case S. aureus var. hominis was isolated more often than in S. aureus var. bovis. This gives grounds to believe that the main source of contamination with milk staphylococci of raw and dairy products of domestic production is people. Enterotoxin type A, which causes foodborne toxemia, was produced by S. aureus in 40.0 ± 0.5% of cases. Consequently, home-produced dairy products can spread staphylococcal toxicity caused by S. aureus var. hominis. It was found that 17.8 ± 0.6% of S. aureus var. hominis were resistant to methicillin, which is 1.8 times greater than that of S. aureus var. bovis. This gives grounds to consider that there is a risk of MRSA infection to consumers of home-produced dairy products. All methicillin-resistant staphylococci studied produced enterotoxins. 

2018 ◽  
Vol 68 (4) ◽  
pp. 613 ◽  
Author(s):  
NISANUR EKTIK ◽  
MUKADDERAT GÖKMEN ◽  
RECEP ÇIBIK

Methicillin-Resistant Staphylococcus aureus is an important pathogen that causes severe infections in humans and animals. The aim of this study was to determine the prevalence and the antimicrobial profile of methicillin-resistant S. aureus (MRSA) in cow bulk tank milk and dairy products in the region of Balikesir in Turkey. Of 175 milk and dairy products’ samples, 26 were found to be positive for coagulase-positive staphylococci and 3 (2 samples from cow bulk tank milk and 1 sample from tulum cheese) were MRSA phenotypically being resistant against both oxacillin and cefoxitin. Among these, 17 were confirmed as S. aureus by the detection of nuc gene and one as MRSA carrying the mecA gene. All MRSA isolates were found to be also resistant against ampicillin, penicillin and sulfamethoxazole-trimethoprim. Consequently, even though the prevalence of MRSA in cow bulk tank milk and dairy productswas relatively low (1.70%), it may pose serious risks in terms of food safety and public health. In order to prevent the prevalence of MRSA in dairy products, hygienic measures, especially in terms of personal hygiene and disinfection of equipment in all stages of dairy production, should be taken, and HACCP and GMP regulations should be implemented.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Fikirte Lemma ◽  
Haile Alemayehu ◽  
Andrew Stringer ◽  
Tadesse Eguale

Staphylococcus aureus is a contagious pathogen that can cause various diseases in both humans and animals. Antimicrobial-resistant S. aureus is becoming an extremely important global health problem. A cross-sectional study was conducted from December 2019 to May 2020 to assess the occurrence of S. aureus and its antimicrobial susceptibility profiles in milk and traditionally processed dairy products in selected subcities of Addis Ababa. A total of 255 dairy product samples (175 raw milk and 80 traditionally processed dairy products) were collected from farms and retail markets. Samples were cultured for S. aureus according to standard microbiology techniques, and the Kirby–Bauer disk diffusion method was used to assess antimicrobial susceptibility of isolates to a panel of 12 antimicrobials. Susceptibility to methicillin was determined based on the sensitivity of isolates to cefoxitin, and resistant isolates were investigated for the presence of mecA and mecC genes using PCR. Staphylococcus aureus was isolated from 43 (24.6%) of milk, 7 (17.5%) of yogurt, and 2 (5%) of cottage cheese. A significantly higher rate of contamination with S. aureus was recorded among milk samples compared to yogurt and cottage cheese ( p = 0.019 ). Out of 52 S. aureus isolates investigated for susceptibility to 12 antimicrobials, 49 (94.2%) of the isolates were resistant to ampicillin and 42 (80.8%) to amoxicillin+clavulanic acid. Twenty (38.5%) of the isolates were methicillin-resistant S. aureus (MRSA) based on susceptibility to cefoxitin. However, only one of these isolates (5%) was positive for mecA gene, and none of them were positive for the mecC gene. There was no significant difference ( p > 0.05 ) in the rate of occurrence of MRSA among isolates from different sources. In conclusion, this study demonstrated a significant level of contamination of milk and dairy products with S. aureus and most isolates were multidrug resistant. The occurrence of MRSA in raw milk and dairy products signifies a serious public health threat as the practice of consuming raw dairy products in the study area is widespread. The lack of agreement between phenotypic and genotypic detection of MRSA suggests the need for further study to identify the genetic basis for the observed resistance phenotype.


2015 ◽  
Vol 143 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Anka Popovic-Vranjes ◽  
Milka Popovic ◽  
Marija Jevtic

Contrary to the safe practices of milk pasteurization or sterilization, which effectively reduce foodborne outbreaks incidence associated with raw milk and dairy products use, outbreaks caused by such products continue to occur. Despite this fact, a worldwide movement advocating for the rights of raw milk and cheese selling and consumption, due to their specific nutritive characteristics, has strengthened significantly in recent years. Traditional agricultural manufacturers from Serbia still sell products related to thermally unprocessed milk, such as cottage cheese and raw cream. In AP Vojvodina during the period of 1981-2010 a total of 179 foodborne outbreaks were reported, where the incriminated cause of the outbreak were milk or diary. In 126 (70.39%) outbreaks, totaling 2276 sick individuals and one casualty, it was confirmed that the incriminated food was from the group of dairy products. In 48 instances (26.82%), bacteriological tests confirmed that milk and dairy products were excluded as the outbreak causes, while in another 5 (2.79%) outbreaks, microbiological analysis of food failed to confirm any relation to the actual epidemiological instances. In some cases, bacteriological testing of incriminated foods was not possible. In the cases of outbreaks associated with the consumption of milk and dairy products, traditional raw milk products were cited as being used. Consumption of unpasteurized milk and cheese represents public health threat. National and international rules ensuring use of safe products for human consumption have to set rules of trade of thermally processed milk and products on the market.


2015 ◽  
Vol 7 ◽  
pp. 169-177 ◽  
Author(s):  
Azar Asadollahi Dehkordi ◽  
Elahe Tajbakhsh ◽  
Forough Tajbakhsh ◽  
Faham Khamesipour ◽  
Manouchehr Momeni Shahraki ◽  
...  

2020 ◽  
pp. 5-9
Author(s):  
Partha Paul ◽  
Md. Zahid Al Hasan ◽  
Arup Kumar ◽  
Mohammad Hasan Chowdhury ◽  
Md. Jayed Chowdhury ◽  
...  

The study was done to isolate Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. from raw milk, processed milk (powdered milk & ultra-high-temperature milk) and dairy products (mango milk, and ice cream). During 3 months’ time span of study, a total of ten samples were gathered where eight of the samples powdered milk (2), ultra-high-temperature milk (2), ice cream (2) & mango milk (2) were gathered from different places of Bangladesh & other 2 samples (raw milk) were collected from a cattle farm & individual households in & around Noakhali city. The samples were gathered under aseptic safety measures and were followed by plating on non-selective media (Nutrient broth) & selective media (Mannitol Salt Agar & Macconkey agar). The presumptive Klebsiella spp., Staphylococcus aureus, Escherichia coli & Pseudomonas spp. isolates were identified by biochemical tests. Analysis of the result discovered that out of a total of 10 samples; raw milk (2), processed milk i.e. powdered milk (2), ultra-high-temperature milk (2) and dairy products i.e. mango milk (2) and ice cream (2) resulted in the isolation of 8 isolates (2.5%) of S. aureus, (12.5%) of Klebsiella spp., (2.5%) of Pseudomonas spp. & (2.5%) of Escherichia coli. Results recommended a probability of potential public health threat of Staphylococcus aureus, Klebsiella spp., Escherichia coli & Pseudomonas spp. resulting from contamination of milk and dairy products with pathogenic microorganisms is mainly due to unhygienic practices and conditions in the handling, production, and processing.


2015 ◽  
Vol 78 (6) ◽  
pp. 1142-1146 ◽  
Author(s):  
ALESSANDRA RIVA ◽  
ELISA BORGHI ◽  
DANIELA CIRASOLA ◽  
SILVIA COLMEGNA ◽  
FRANCESCA BORGO ◽  
...  

Staphylococcus aureus is a known major cause of foodborne illnesses, and raw milk and dairy products are often contaminated by enterotoxigenic and antimicrobial-resistant S. aureus strains. In the present study, 35 S. aureus strains were isolated from 383 raw milk samples collected from various dairy herds in the province of Milan (northern Italy). The isolates were characterized based on their antimicrobial susceptibility patterns and the presence of genes encoding staphylococcal enterotoxins (sea, seb, sec, sed, and see). About half (45.7%) of the strains were enterotoxigenic, and 37.1% were resistant to at least one of the antimicrobial drugs tested. Seven (20%) of 35 isolates were identified as methicillin-resistant S. aureus (MRSA), and SCCmec typing performed with a multiplex PCR assay revealed the presence of gene cassettes IV and V, typical of community-acquired MRSA, and I and II, characteristic of health care–associated MRSA. The MRSA strains were evaluated for the presence of the Panton-Valentine leukocidin gene, but this gene was not found. The results of the present study revealed the presence of toxin-producing S. aureus and MRSA strains in raw milk. MRSA and enterotoxigenic S. aureus in dairy farms are an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for monitoring and controlling the presence of S. aureus, especially MRSA, in dairy products.


2019 ◽  
Vol 7 (4) ◽  
pp. 121-125
Author(s):  
Fatemeh Mahdavi ◽  
Fatemeh Zaboli ◽  
Rahem Khoshbakht

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are one of the most important multidrug resistant microorganisms that threaten human health. Objective: The present study was conducted to evaluate genotypic and phenotypic characteristics of erythromycin resistance among MRSA isolates recovered from raw milk in Iran. Materials and Methods: A total of 50 MRSA isolates were recovered from raw milk. Tests for erythromycin and clindamycin susceptibility and inducible clindamycin resistance were done. In addition, the presence of the methicillin resistance determinant (mecA), erythromycin resistance genes (ermA, ermB, ermC and msrA) and an important virulence gene (Panton– Valentine leukocidin) were investigated using polymerase chain reaction (PCR) method. Results: Forty-eight percent (24/50) and 46% (23/50) of the isolates were resistant to erythromycin and clindamycin, respectively. Seven (14%) isolates showed inducible clindamycin resistance phenotype. The mecA gene was detected in 88% (44/50) of MRSA isolates. The incidence of the ermA, ermB, ermC and msrA genes was 14%, 64%, 12%, and 26%, respectively and the PVL gene was present in 18% (9/50) of MRSA isolates. Conclusion: According to the results of the study, the incidence of erythromycin resistance genes and inducible clindamycin-resistant MRSA strains was high in raw milk samples in Iran.


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