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In this study, Neutral electrolyzed water (NEW) bactericidal efficacy and inactivating capacity as a promising novel antimicrobial agent, green sanitizer and natural alternative to conventional decontamination techniques as chemical disinfectants was evaluated by using NEW with free available chlorine (FAC) at concentrations of 7.5 ppm (NEW 1%), 24 ppm (NEW 12%) and 49 ppm (NEW 25%) against food-borne related microorganisms and their biofilms. Our Results revealed that by 10 min of exposure to the sanitizer (NEW) with different concentrations, changes to the bacterial count, bacterial cell morphology, biofilms were evaluated by plate counting, minimum inhibitory concentration method (MIC), Transmission Electron microscope (TEM) examination for the isolated Salmonella Typhimurium, Enteropathogenic E. coli (EPEC), and S. aureus, respectively. Beside, modulation of bacterial gene expression by real time Polymerase Chain Reaction screening (RT-PCR) for methicillinresistant gene (mecA) and Enterotoxin gene (seb) of S. aureus. It was shown from the results that Salmonella Typhimurium highest reduction percentage achieved was 99.9% after 10 min exposure to 12% and 25% NEW concentrations, while EPEC and S. aureus highest reduction percentages achieved were 99.8%, and 99.95% after 10 min exposure to 25% NEW concentration, respectively. The lowest reduction was detected by 59.5% for S. aureus treated with NEW 1% for 5 min. While MIC for NEW 25% was 12.25 ppm for EPEC and 24.5 ppm for each of Salmonella Typhimurium and S. aureus. TEM photos revealed that NEW has achieved a broad-spectrum bactericidal activity by causing changes and destruction in cell envelope and cytoplasm of all strains. RT-PCR showed downregulation of enterotoxin (seb) and resistant genes (mecA) of S. aureus. In conclusion, the study demonstrated that NEW as a green sanitizer is significant in reduction and elimination of the most food-borne bacterial contamination. [ABSTRACT FROM AUTHOR]

Bacillus cereus (B. cereus) is Gram-positive, spore-forming bacterium not only associated with food-borne outbreaks but also responsible for spoilage of food products. Therefore, the aim of this study is to trying to control of B. cereus by safe nanoparticles and studies the antibacterial effects of Nigella sativa and green synthesized Zinc Oxide nanoparticles (NPs) on B. cereus. The isolated strains of B. cereus from meat and milk products with detection of their virulence genes (nhe, cytK, hbl and ces) by PCR were used to assess the antibacterial activity of these nanoparticles. The nanoparticles were characterized by Scanning Electron Microscope (SEM) and Dynamic Light Scattering (DLS) to investigate their properties which revealed that Nigella sativa NPs was 87.5 nm in size and cuboidal in shape, the polydispersity index, zeta potentials, viscosity and conductivity were 0.456, +15.9 mV, 0.877 cp and 58 uS/cm respectively, while Zinc Oxide NPs were 0.2484, -21.8 mV, 0.925 cp and 269 uS/cm respectively and their size was 67.8 nm and rhomboid in shape. Antibacterial activity was determined by using micro wells dilution method to determine Minimum Inhibitory Concentration (MIC). The MIC result for Nigella sativa NPs showed slight inhibition with the 30% concentration, while for Zinc Oxide NPs was 1.25 mg/ml. The morphological characters and changes of bacterial cells before and after treatment with nanoparticles were described by SEM. The Results show significant inhibitory effect of Zinc Oxide NPs than Nigella sativa NPs on B. cereus growth with distinctive destruction in its ultrastructure. SO, applications of nanoparticles in the meat and dairy industry will be a market trend to improve quality by their antibacterial effects and enhancement their shelf life. [ABSTRACT FROM AUTHOR]

Background: Carbapenem-resistant A. baumannii (CRAB) bacterium is difficult to treat with available antimicrobial agents leading to use a few antibiotics such as colistin as an option for treatment. However, the use of the colistin has serious side effects and leads to developing bacterial resistance. Objective: This study aimed to determine effectiveness of phage/colistin combination to inhibit biofilm formation of CRAB. Methods: Sixty clinical A. baummanii isolates were identified with the VITEKII system and 16S rRNA gene. The antibiotic susceptibility and detection of Oxacillinases genes were tested for all isolates. Results: The antibiotic sensitivity of A. baumannii isolates showed a high resistance percentage to Ceftriaxone (CRO) with 92% (55 isolates), and Cefotiam (CTF) with 87% (52 isolates), while the lowest percent related to Colistin (CO) with 17% (10 isolates). The results of antibiotic resistance and Oxacillinases genes reported that only 14 isolates from the current study were CRAB. Phage and host A. baumannii of phage were isolated and characterized previously. Biofilm production assay of CRAB isolates were showed that among 14 isolates including the phage host: 57% (8) was weak and 43% (6) was moderate biofilm producer. Therefore, the synergistic effect of a combination ΦKAB phage in MOI (10) and Colistin with MIC=8 µg/ml against CRAB isolates was evaluated and showed complete transfer of isolates by 100 % to weak biofilm producer compared with CRAB isolates. Conclusions: Among 60 isolates of A. baumannii, most isolates were MDR 44 (73.3%) and only 14 (23.3%) isolates were CRAB that were 57% weak and 43% moderate biofilm producers. The mixture of Colistin/ΦKAB phage could inhibit and reduce biofilm forming in CRAB isolates. Overall, the present study may provide evidence on the capability of the isolated phage to serve as a novel strategy to treat infections caused by MDR A. baumannii. [ABSTRACT FROM AUTHOR]

Mastitis is an inflammation of the mammary gland caused in dairy cows due to bacterial infections causing high economic losses. Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR) is an effective genotyping tool for tracing the infection by different bacteria. One hundred milk samples were collected (50 from clinical mastitis and 50 from subclinical mastitis) from different dairy farms at different regions of El-Gharbia governorate in Egypt. The samples were examined bacteriologically for the isolation and identification of Klebsiella pneumoniae and Corynebacterium bovis. Antibiotic sensitivity testing for the isolates and genotyping by ERIC-PCR were performed. Our results showed that the prevalence of K. pneumoniae was 41% from total samples and C. bovis strains was18% from subclinical mastitis milk samples. All the examined isolates were multi drug resistant with higher resistance to ampicillin, amoxicillin-clavulanate and cefotaxime for K. pneumoniae and to penicillin, erythromycin and tetracycline for C. bovis. Discriminatory index of ERIC-PCR was 0.984 and 1 for K. pneumoniae and C. bovis isolates, respectively. The dendrogram analysis for K. pneumoniae showed three clusters and two separate isolates, while for C. bovis 1 cluster with 2 sub clusters and three separate isolates were observed. It was concluded that ERIC-PCR is proven to be effective genotyping technique with high discriminatory index and is a good epidemiological tool for mastitis in cows as there was a genetic relatedness between some strains collected from different regions at El-Gharbia governorate in Egypt. This indicated the possibility of infection transmission between these regions and necessitates the need to increase control measures. [ABSTRACT FROM AUTHOR]

In poultry, Escherichia coli infections lead to substantial deaths and financial losses for producers each year. This study aimed to investigate the prevalence of E. coli from water pipes and drinkers in broiler farms, to characterize the isolated E. coli strains in terms of serotypes, biofilm production degree, presence of the adrA gene. The gene “adrA” encodes for the adhesion regulating protein A. adrA is a protein that plays a role in regulating the adhesion and biofilm formation of E. coli bacteria., and the efficacy of various disinfectants on E. coli biofilms. A total of 100 swab samples were collected from drinking water pipes and drinkers from different broiler farms in Giza and Dakahlia governorates in Egypt. Out of them, 18 E. coli serogroups were identified in 50 positive samples, and the most predominant serogroup was O91, which showed the highest incidence (20%), followed by serotypes O78 (18%), and O26 (8%). Microtiter-plate test for determination of biofilm production for 50 E. coli isolates were performed. PCR was done for the detection of the virulence gene adrA in the 13 strong biofilm E. coli isolates, and the results revealed that 100% were positive for the virulence gene. The effect of disinfectants on E. coli was studied by using ZnO nanoparticles, acidifiers, and quaternary ammonium dioxide. This study found a high prevalence of E. coli in water samples, identified various E. coli serotypes, observed biofilm production, and determined the effectiveness of different disinfectants on E. coli isolates. [ABSTRACT FROM AUTHOR]

Edible films and essential oil (EO) systems have the potency to enhance the microbial quality and shelf life of food. This investigation aimed to evaluate the efficacy of chitosan films including essential oils against spoilage bacteria and foodborne pathogens associated with meat. Antimicrobial activity (in vitro and in vivo) of chitosan films (CH) incorporated with oregano oil (OO) and thyme oil (TO) at 0.5 and 1% was done against spoilage bacteria and foodborne pathogens, compared to the control sample and CH alone. Preliminary experiments (in vitro) showed that the 1% OO and TO were more active against Staphylococcus aureus compared to Escherichia coli O157:H7 and Salmonella Typhimurium. In in vivo studies, CH containing OO and TO effectively inhibited the three foodborne pathogens and spoilage bacteria linked with packed beef meat which was kept at 4 °C/30 days compared to the control. The total phenolic content of the EOs was 201.52 mg GAE L−1 in thyme and 187.64 mg GAE L−1 in oregano. The antioxidant activity of thyme oil was higher than oregano oil. The results demonstrated that the shelf life of meat including CH with EOs was prolonged ~10 days compared to CH alone. Additionally, CH-OO and CH-TO have improved the sensory acceptability until 25 days, compared to the control. Results revealed that edible films made of chitosan and containing EOs improved the quality parameters and safety attributes of refrigerated or fresh meat. [ABSTRACT FROM AUTHOR]

The public health importance of the genus Campylobacter is attributed to several species causing diarrhea in consumers. Poultry and their meat are considered the most important sources of human campylobacteriosis. In this study, 287 samples from chicken (131 cloacal swabs, 39 chicken skin, 78 chicken meat, and 39 cecal parts) obtained from retail outlets as well as 246 stool swabs from gastroenteritis patients were examined. A representative number of the biochemically identified Campylobacter jejuni isolates were identified by real-time PCR, confirming the identification of the isolates as C. jejuni. Genotyping of the examined isolates ( n = 31) by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) revealed a high discriminatory index of ERIC-PCR ( D = 0.948), dividing C. jejuni isolates of chicken and human origins into 18 profiles and four clusters. The 18 profiles obtained indicated the heterogeneity of C. jejuni. Dendrogram analysis showed that four clusters were generated; all human isolates fell into clusters I and III. These observations further support the existence of a genetic relationship between human and poultry isolates examined in the present study. In conclusion, the results obtained support the speculation that poultry and poultry meat have an important role as sources of infection in the acquisition of Campylobacter infection in humans. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the prevalence and antimicrobial resistance of enterococci- and ESBL-producing E. coli isolated from milk of bovine mastitis cases in Egypt. Fifty milk samples of dairy animals were collected from localities in the Nile Delta region of Egypt. Isolates were identified using MALDI-TOF MS, and antibiotic susceptibility testing was performed by the broth microdilution method. PCR amplifications were carried out, targeting resistance-associated genes. Seventeen Enterococcus isolates and eight coliform isolates could be cultivated. Vancomycin resistance rate was high in Ent. faecalis. The VITEK 2 system confirmed all E. coli isolates as ESBL-producing. All Ent. faecalis isolates harbored erm(B), tetL and aac-aphD genes. The vanA gene was detected in Ent. faecalis isolate, vanB was found in other Enterococcus, while one isolate of E. casseliflavus exhibited the vanA gene. E. coli isolates exhibited high prevalence of erm(B) and tetL. E. coli isolates were analyzed by DNA microarray analysis. Four isolates were determined by O-serotyping as O8 (n = 1), O86 (n = 2) and O157 (n = 1). H-serotyping resulted in H11, H12, H21 (two isolates each) and one was of H16 type. Different virulence-associated genes were detected in E. coli isolates including lpfA, astA, celB, cmahemL, intI1 and intI2, and the iroN gene was identified by DNA microarray analysis. [ABSTRACT FROM AUTHOR]