Tracked Changes. Microbiology of the food chain. Horizontal method for the enumeration of coagulase-positive staphylococci (Staphylococcus aureus and other species)

2021 ◽  
Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Eman E. Abdeen ◽  
Walid S. Mousa ◽  
Sarah Y. Abdelsalam ◽  
Hanim S. Heikal ◽  
Reyad R. Shawish ◽  
...  

Methicillin-resistant Staphylococcus aureus (MRSA) strains have veterinary and public health importance as they are responsible for a wide range of difficult to treat infections and food poisoning. Two hundred samples (50 samples each of minced meat, beef luncheon, Karish cheese, and human samples (pus swab from open wounds)) were cultured, and MRSA strains were identified using disk diffusion tests and mecA gene-based PCR. A total of 35% (70/200) of the examined samples were confirmed as coagulase-positive S. aureus in minced meat (46%), beef luncheon (44%), Karish cheese (44%), and human samples (22%). The MRSA strains showed resistance to amoxicillin (91.4%), penicillin (97.1%), cefoxitin (85.7%), cephradine (82.9%), tetracycline (57.2%), and erythromycin (52.8%). More than half of the tested S. aureus isolates harbored the mecA gene. The sequence analysis of the mecA gene from the minced meat, Karish cheese, and human samples revealed high genetic similarities between the S. aureus isolates from these sources. In conclusion, our findings indicate a risk for the transmission of the mecA gene of S. aureus across the food chain between humans and animal food products. Further studies should focus on finding additional epidemiological aspects of the MRSA strains in food chain.


2015 ◽  
Vol 18 (3) ◽  
pp. 627-634 ◽  
Author(s):  
M. Kizerwetter-Świda ◽  
D. Chrobak-Chmiel ◽  
M. Rzewuska ◽  
A. Antosiewicz ◽  
B. Dolka ◽  
...  

AbstractCoagulase-positive staphylococci (CoPS) are opportunistic veterinary pathogens, of whichStaphylococcus aureus,S. delphiniandS. intermediuscan be isolated from pigeons. The biochemical identification ofS. delphiniandS. intermediusisolates may be incorrect, because of their phenotypic similarity. The purpose of the present study was to isolate and identify CoPS from domestic and feral pigeons and to determine their genetic relatedness by PFGE. A total number of 31 isolates of CoPS were obtained, 15 were identified asS. delphinigroup B, six asS. aureus,four asS. delphinigroup A, three asS. intermediusand three asS. schleiferisubsp.coagulans. The results indicate that S.delphinigroup B is the predominant CoPS species among pigeons studied. PFGE restriction patterns ofS. delphinigroup A andS. delphinigroup B form separate clusters, demonstrating their genetic heterogeneity. Indistinguishable or very similar PFGE patterns observed amongS. delphinigroup B isolates from domestic and feral pigeons confirm the possibility of CoPS transmission between these birds.


1981 ◽  
Vol 44 (1) ◽  
pp. 4-8 ◽  
Author(s):  
ENEFIOK J. NKANGA ◽  
NDUKA URAIH

An investigation was carried out for detection and enumeration of coagulase-positive Staphylococcus aureus from fresh, fried and dried meat samples sold in the traditional markets in Benin City. Using Salt Milk Agar for presumptive detection and coagulase test for confirmation, it was found that all samples of meat from the traditional markets contained coagulase-positive staphylococci. Weekly sampling was done over a 6-month period to demonstrate the prevalence of the coagulase-positive staphylococci in both traditional market, supermarket and abattoir meat samples. The range of counts fell between 104 and 1011 cells per gram. Fresh pork from the traditional market had the highest average number, 6.4×1010/g, followed by dried beef 3.7×1010/g, fresh goat and fried chicken 6.8×109/g each and fresh beef 7.0×109/g. The supermarket meat showed that chilled beef had the highest, 4.5×105/g, followed by chilled pork 3.0×105/g and frozen chicken 2.0×104/g. The abattoir meat had 3.5×104/g. The effects of condiments on inhibition of S. aureus were determined in abattoir meat homogenates. Clove was the most active of the spices tested with 1% (w/v) preventing outgrowth of S. aureus for up to 18-h contact time. When used at 10% (w/v), clove was found to be bactericidal, reducing the S. aureus load from 2.9×103/ml of homogenate at 0 h to 1.2×101/ml after 18 h of contact time.


1970 ◽  
Vol 43 (4) ◽  
pp. 455-466 ◽  
Author(s):  
Iftekhar M Rafiqullah ◽  
AMM Maruf Hossain ◽  
Mohammad Ilias ◽  
M Mozammel Hoq

Feeds and fertilizer production from tanned skin-cut wastes is the most direct phenomenon of chromium eco-toxicity leading to food chain contamination in Bangladesh. Tanning industries of Hazaribagh at Dhaka process some 220 t of hide per day with release of 600-1000 Kg tanned skin-cut waste (SCW) per ton processed hide. The SCW is protein-rich and unscientifically used to produce poultry and fish feeds, and organic fertilizer. A huge migration of chromium can happen into poultry products, fish and vegetables, and further bio-magnify into food chain. The target population is also huge. It is reported that feed ingredients produced from SCW contained chromium at levels as high as 2.49%. As Cr(VI) is the most toxic species of chromium, reduction of Cr(VI) to Cr(III) prior to be used as feed ingredients and fertilizers can ensure safer input of chromium in toxicological point of view. Samples have been collected to isolate microorganisms from effluent sites of Hazaribagh tanning area using Lauria-Bertani medium with added Cr(VI) as K2Cr2O7. The successful as well as apparently differing colonies (isolates IF-10 to IF-12, IF-16, and IF-19 to IF-23) have been studied for growth characterization under differing Cr(VI) concentrations up to 1500 mg/L. Cultural and biochemical tests of the isolates have narrowed the range into 3 strains. These strains have been identified by 16s rRNA gene sequence analysis. The isolates are found to be Escherichia sp. (Isolate IF-10 to IF-12, Strain IFR-I), Staphylococcus aureus (Isolate IF-16, Strain IFR-II), and Pediococcus pentosaceus (Isolate IF-19 to IF-23, Strain IFRIII). The organisms have been studied for Cr (VI) reduction-ability in growth dependent manner which are found successful up to 82.88 % for Staphylococcus aureus, and 100 % for Escherichia sp. and Pediococcus pentosaceus within 24 h. Key words: Bacteriology, Enzymatic reduction, Bioremediation, Chromium eco-toxicity   doi: 10.3329/bjsir.v43i4.2236 Bangladesh J. Sci. Ind. Res. 43(4), 455-466, 2008


1996 ◽  
Vol 59 (8) ◽  
pp. 819-826 ◽  
Author(s):  
STEFAN T. MARTIN ◽  
ROBERT B. BEELMAN

Freshly harvested mushrooms were found to induce a near-anaerobic environment (<2% O2) in unventilated, PVC-overwrapped packages within 2 to 6 h when incubated at 20 to 30°C. Mushrooms were inoculated with an enterotoxigenic strain of Staphylococcus aureus and incubated in overwrapped trays at different temperatures. S. aureus grew and produced staphylococcal enterotoxin (SE) in unventilated PVC-overwrapped mushroom packages when inoculated at levels of 103, 104, and 105 CFU/g of mushroom after 4 days of incubation at 30°C. Growth of S. aureus was observed at all levels of inoculation at 25°C, but no SE was detected after 7 days of incubation. When mushroom packages were ventilated, S. aureus growth was suppressed and no SE was detected after 7 days at 25°C and 4 days at 30°C. However, S. aureus growth in ventilated packs exceeded growth in unventilated packages when the incubation temperature was increased to 35°C; SE was detected within 18 h of incubation at this temperature, even in mushrooms inoculated at a low level (102 CFU/g). These results show the extreme importance of proper sanitation and worker hygiene during mushroom harvesting and packaging, ventilation of fresh mushroom packages, and proper storage temperatures for fresh mushrooms at all points of the food chain.


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