Modified Vogel and Johnson Agar for Staphylococcus aureus

1978 ◽  
Vol 41 (7) ◽  
pp. 530-532 ◽  
Author(s):  
GAIL P. ANDREWS ◽  
SCOTT E. MARTIN

The formula for a modified Vogel and Johnson Agar is presented. In addition to the ingredients found in Vogel and Johnson Agar, the new medium contains, per liter: 5 g of beef extract, 2 g of deoxyribonucleic acid, 2 g of phosphatidyl choline and 780 units of catalase spread on the plates before inoculation. This new medium is as effective as Baird-Parker Agar in enumeration of stressed Staphylococcus aureus, and in enumeration of staphylococci from naturally contaminated processed food samples.

Author(s):  
Mashael J. Alghizzi ◽  
Maysoon Alansari ◽  
Ashwag Shami

Staphylococcus aureus mainly Methicillin Resistant Staphylococcus aureus(MRSA) is a life-threatening infection that occurring in food and caused a public health concern. This study designed to examine the prevalence of S. aureus and MRSA in different types of processed food. Food samples were screened for the recovered strains of S. aureus and MRSA, and they were examined for antimicrobial susceptibility and by molecular characterization of mecA and staphylococcal cassette chromosome mec(SCCmec). Detection of virulence factors like Panton-Valentine Leukocidin (PVL), Staphylococcus aureus protein A(spa) and Staphylococcal enterotoxins(SEs) by PCR using specific primers. Among the 150 collected processed food samples, 62.7% were contaminated by S. aureus bacteria, 56.4% of which were proved as MRSA. 17% of MRSA isolates were positive for mecA genes with the SCCmec type IVb and V (11.1% each) as the solely existing types of SCCmec. None of the MRSA isolates carried mecC or mecB genes. Most of MRSA isolates were multidrug resistance and 33.3% of MRSA-mecA positive isolates also carried vancomycin resistance genes (i.e., vanB). In addition, spa gene was found among 7.5% of MRSA isolates; none of which were positive for PVL gene. Further, there were variant presence of SEs among MRSA isolates and the highest presence was from type SEH (49.1%). Generally, our results confirmed that processed foods in Saudi Arabia (Riyadh) are potential vehicles for multidrug resistant S. aureus and MRSA transmission; which are serious public health risks, and underlined the need for good hygiene practices.


1999 ◽  
Vol 82 (7) ◽  
pp. 1581-1585 ◽  
Author(s):  
B.E. Gillespie ◽  
W.E. Owens ◽  
S.C. Nickerson ◽  
S.P. Oliver

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Arash Mesbah ◽  
Zohreh Mashak ◽  
Zohreh Abdolmaleki

Abstract Background Resistant Staphylococcus aureus (S. aureus) bacteria are considered among the major causes of foodborne diseases. This survey aims to assess genotypic and phenotypic profiles of antibiotic resistance in S. aureus bacteria isolated from ready-to-eat food samples. Methods According to the previously reported prevalence of S. aureus in ready-to-eat food samples, a total of 415 ready-to-eat food samples were collected from Tehran province, Iran. S. aureus bacteria were identified using culture and biochemical tests. Besides, the phenotypic antibiotic resistance profile was determined by disk diffusion. In addition, the genotypic pattern of antibiotic resistance was determined using the PCR. Results A total of 64 out of 415 (15.42%) ready-to-eat food samples were contaminated with S. aureus. Grilled mushrooms and salad olivieh harbored the highest contamination rate of (30%), while salami samples harbored the lowest contamination rate of 3.33%. In addition, S. aureus bacteria harbored the highest prevalence of resistance to penicillin (85.93%), tetracycline (85.93%), gentamicin (73.43%), erythromycin (53.12%), trimethoprim-sulfamethoxazole (51.56%), and ciprofloxacin (50%). However, all isolates were resistant to at least four antibiotic agents. Accordingly, the prevalence of tetK (70.31%), blaZ (64.06%), aacA-D (57.81%), gyrA (50%), and ermA (39.06%) was higher than that of other detected antibiotic resistance genes. Besides, AacA-D + blaZ (48.43%), tetK + blaZ (46.87%), aacA-D + tetK (39.06%), aacA-D + gyrA (20.31%), and ermA + blaZ (20.31%) were the most frequently identified combined genotypic patterns of antibiotic resistance. Conclusion Ready-to-eat food samples may be sources of resistant S. aureus, which pose a hygienic threat in case of their consumption. However, further investigations are required to identify additional epidemiological features of S. aureus in ready-to-eat foods.


2020 ◽  
pp. 3164-3171
Author(s):  
Andalus S. Atiyah ◽  
Marwa H. Alkhafaji

The microbial production of substances that have the ability to inhibit the growth of other microorganisms is possibly the most common defense strategy developed in nature. Microorganisms produce a variable collection of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. The aim of the present study was to isolate and identify Enterococcus spp. and  its most prevalent species from food samples and determine its antibacterial activity against Staphylococcus aureus isolates. A total of 50 food samples from different sources (dairy products (20 samples) and vegetables and fish (15 samples each)) were collected from different local markets in Baghdad and cultured. Enterococcus spp were isolated from only 32 food samples. E. faecium was the most predominant species which was recovered from 20 samples (62.5 %), 10 dairies, 7 vegetables, and 2 fish. E. faecalis was found in 8 samples (25 %), 5 vegetables and 3 fish.  E. avium was recovered 6.25% as well as E. gallinarium (2 samples for each) Enterococcus avium were all isolated from dairy products but Enterococcus gallinarium one sample isolated from dairies and the other from fish. This study indicates the presence of Enterococcus spp. in the food samples and the ability of these bacteria to produce antibacterial substances which are active against closely related clinical isolates.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mohammed Yahya Ahmed ◽  
Hashim Abdalbagi Ali ◽  
Babbiker Mohammed Taher Gorish ◽  
Sara Omer Ali ◽  
Eman Saif Aldein Abdalrhim ◽  
...  

Staphylococcal food poisoning is an intoxication that results from the consumption of improperly prepared or stored foods containing sufficient amounts of one or more preformed S. aureus enterotoxins. Nowadays, many researchers worldwide noted an emergence of resistant strains such as Staphylococci particularly for the antibiotic methicillin. Therefore, this study was aimed to determine the existence of Staphylococcus aureus and its enterotoxins, mecA genes, in selected food samples. A total of 400 selected food samples were collected from different areas in Khartoum State. The selected foods included cheese, meat products, fish, and raw milk. One hundred samples from each type of food were cultivated, and the resultant growth yielded 137 (34.25%) S. aureus, 126 (31.5%) bacteria other than S. aureus, and 137 (34.25%) yielded no growth. Eighty-four of the 137 S. aureus isolates were randomly selected and tested for the presence of mecA and enterotoxin genes. The oxacillin sensitivity test showed that 15 (11%) of 137 S. aureus isolates were oxacillin resistant. The PCR assay showed that the mecA gene was detected in 15 of 84 (17%) S. aureus isolates. Simultaneously, only 2 (2.385%) out of 84 S. aureus isolates showed an enterotoxin B gene product. There was a relatively moderate prevalence of methicillin-resistant Staphylococcus aureus with very low frequency of enterotoxin B gene in different kinds of selected food samples collected from Khartoum State. These findings elucidate the increased risk on public in Khartoum being affected by Staphylococcal food poisoning upon consumption of dairy or meat products prepared in unhygienic conditions that could lead to intoxication by Staphylococcus aureus enterotoxins.


2019 ◽  
Vol 82 ◽  
pp. 107-110 ◽  
Author(s):  
Narciso M. Quijada ◽  
Marta Hernández ◽  
Elena-Alexandra Oniciuc ◽  
José María Eiros ◽  
Isabel Fernández-Natal ◽  
...  

2013 ◽  
Vol 65 (5) ◽  
pp. 1537-1544 ◽  
Author(s):  
S.A. Carvalho ◽  
L.S. Carmo ◽  
E.F. Abreu ◽  
R.S. Dias ◽  
A.C.M. Apolônio ◽  
...  

The production of Toxic Shock Syndrome Toxin-1 (TSST-1), enterotoxins and bacteriocin-like substances was evaluated in 95 strains of Staphylococcus aureus recovered from raw bovine milk (n=31) and from food samples involved in staphylococcal food poisoning (n=64). Enterotoxigenicity tests with the membrane over agar associated to optimal sensibility plate assays were performed and showed that 96.77% of strains recovered from milk and 95.31% from food samples produced enterotoxins A, B, C, D or TSST-1. Reference strains S. epidermidis, Bacillus cereus, Listeria monocytogenes, Lactobacillus casei, Pseudomonas aeruginosa, S. aureus, Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis and Bacteroides fragilis were used as indicator bacteria in the antagonistic assays, the first five being sensitive to antagonistic substances. Brain heart infusion agar, in pH values ranging from 5.0 to 7.0 in aerobic atmosphere showed to be the optimum condition for antagonistic activity as evaluated with the best producer strains against the most sensitive indicator bacterium, L. monocytogenes. Sensitivity to enzymes confirmed the proteinaceous nature of these substances. Neither bacteriophage activity nor fatty acids were detected and the antagonistic activity was not due to residual chloroform. Results did not establish a positive correlation between the bacteriocinogenic profile and toxigenicity in the tested S. aureus strains.


1981 ◽  
Vol 44 (4) ◽  
pp. 271-274
Author(s):  
ADELLE W. STEWART

The fate of naturally occurring and added bacterial pathogens was determined in “soul foods” purchased at local supermarkets and farm families while the foods were stored under conditions simulating those used for retail distribution, home storage, and preparation before use. Viable count determinations for 10 samples at the end of a 5-day period at 10 C showed considerable decreases in comparison to the inoculum size, indicating that growth was not promoted. Escherichia coli survived in all the food samples but the populations decreased by 1 to 9 log cycles/g of food. Salmonella typhimurium survived in 59% of the food samples. Except for farm family collard greens and sausage (encased), Staphylococcus aureus remained viable in all of the foods tested an d was the only survivor in cracklings (cooked) obtained from both sources. Clostridium perfringens was detected in farm family sweet peas and 23% of the pig offal samples.


2019 ◽  
Vol 6 (4) ◽  
Author(s):  
Johnny Gutierrez ◽  
Alessander O Guimaraes ◽  
Nicholas Lewin-Koh ◽  
Aklile Berhanu ◽  
Min Xu ◽  
...  

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