Aim:This review gives an outline of the assessment of enterotoxigenic Staphylococcus aureus tainting levels in raw milk from different sources in Egypt and characterization of enterotoxigenic strains utilizing a technique in light of PCR to identify genes coding for the production of staphylococcal enterotoxin (SE). The obtained data were compared with results from the application of the reversed passive latex.Materials and Methods:Multiplex PCR and reversed passive latex agglutination (RPLA) were used. A total of 141 samples of raw milk (cow’s milk=33, buffalo’s milk=58, and bulk tank milk=50) were investigated for S. aureus contamination and tested for enterotoxin genes presence and toxin production.Results:S. aureus was detected in 23 (16.3%) samples phenotypically and genotypically by amplification of nuc gene. The S. aureus isolates were investigated for SEs genes (sea to see) by multiplex PCR and the toxin production by these isolates was screened by RPLA. SEs genes were detected in six isolates (26.1%) molecularly; see was the most observed gene where detected in all isolates, two isolates harbored seb, and two isolates harbored sec. According to RPLA, three isolates produced SEB and SEC.Conclusion:The study revealed the widespread of S. aureus strains caring genes coding for toxins. The real significance of the presence of these strains or its toxins in raw milk and their possible impact a potential hazard for staphylococcal food poisoning by raw milk consumption. Therefore, detection of enterotoxigenic S. aureus strains in raw milk is necessary for consumer safety.

Background: Pseudomonas aeruginosa is a pit of an enormous group of free-living bacteria that are able to live everywhere and suggested to be the causative agent of great scope of acute and chronic animal infections. Aim: The current study was carried out to illustrate the prevalence of P. aeruginosa in small ruminants and existence of some virulence operons as well as its antimicrobial resistance. Materials and Methods: A total of 155 samples from sheep and 105 samples from goats (mouth abscesses, fecal swabs, nasal, tracheal swabs, and lung tissue) were collected for bacteriological study, existence of some virulence expression operons with the study of their sensitivity to the antimicrobials using disc diffusion and presence of mexR operon which is responsible for multidrug resistance (MDR). Results: The bacteriological examination revealed that P. aeruginosa was isolated from nine out of 155 samples from sheep (5.8%) and four isolates out of 105 samples from goat (3.8%). It is found that 12 (92.3%), 10 (76.9 %), and 8 (61.5%) of P. aeruginosa isolates harbored hemolysin phospholipase gene (pclH), gene (exoS), and enterotoxin gene (toxA), respectively. The results of antibiotic sensitivity test showed that all tested isolates were resistant to ampicillin, bacitracin, erythromycin, streptomycin, tetracycline, trimethoprim-sulfamethoxazole, and tobramycin but sensitive to ciprofloxacin and norfloxacin. The MDR (mexR) operon was existed in all isolates. Conclusion: There is a growing risk for isolation of virulent MDR P. aeruginosa from sheep and goat illness cases, and this should be regarded in the efficient control programs.

Infectious diseases are the most important cause of death worldwide. Many of these diseases show great resistance to drugs and antibiotics with long-term use. Extracts of some medicinal plants have antimicrobial properties, which can treat and overcome these diseases. Meliaceae is a family of timber trees used extensively in treating many bacterial and fungal diseases, especially Swietenia mahagoni (L.) Jacq. In this study, phytochemical screening, gas chromatography/mass spectrometry (GC/MS) analysis, and antimicrobial, antioxidant, and antitumor activities of the methanolic extract of S. mahagoni (L.) leaves were performed. Phytochemical screening exhibited the presence of alkaloids, flavonoids, saponins, phenols, triterpenoids, glycosides, and tannins. GC/MS analysis exhibited 40 compounds, mainly 7-hexadecene, (Z)-, imidazole-4,5-d2, and 1-acetyl-4,4-bis[4-(3-bromopropoxy)-3,5-dimethoxyphenyl] piperidine. The antibacterial and antifungal potentials of the methanolic extract of S. mahagoni (L.) leaves was investigated using the agar well diffusion technique. Potent antibacterial activity against Staphylococcus aureus, Escherichia coli, Salmonella enterica, Enterobacter aerogenes, and Proteus vulgaris and antifungal activity against Aspergillus flavus, Aspergillus niger, and Candida albicans were found. The minimum inhibitory concentration and minimum bactericidal and fungicidal concentrations ranged from 12.5 to 25 mg/mL. Antioxidant activity was studied using the free radical scavenging assay, and the IC50 value of the leaf extract was 69.9 µg/mL. Cytotoxic activity was screened using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the IC50 value was 44.2 µg/mL. These findings suggested the importance of this plant in treating some bacterial and fungal infections and cancer.

This article discusses the augmenting influence of Artesunate (ART) in combination with β-lactams (amoxicillin/clavulanic acid) antibiotic in sepsis mice models infected by a lethal challenge dose of live coagulase positive enterotoxigenic (Sec) MRSA that was isolated from a case of chronic bovine mastitis. The main goal is to find an appropriate treatment to overcome resistance mechanism of MRSA towards β-lactams antibiotic. Fifty healthy adult Swiss mice divided into 5 equal groups were used in the experimental procedure. The infected group that treated with both ART and β-lactams (amoxicillin/clavulanic acid) antibiotic revealed complete inhibition of MRSA count with complete normal macroscopic and histopathological features. We suggest that ART can potentiate the antibacterial action of β-lactams (amoxicillin/Clavulanic) acid against MRSA infection. The combination of ART and antibiotic can overcome MRSA resistance mechanism and so could be considered a novel candidate to overcome mastitis and/or sepsis caused by MRSA.

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