This study evaluates the antimicrobial effects of ethanolic extract of five herbal plants; Guava (Psidium guajava ), Sage ( Salvia officinalis ), Rhamnus ( Ziziphusspina Christi ), Mulberry ( Morusalba L.), and Olive ( Oleaeuropaea L ) leaves against several microbial population representing Gram positive, Gram negative and Mollicutes; S. aureus, E. coli, Pasteurella multocida , B. cereus , Salmonella Enteritidis and M. gallisepticum using standard agar disc diffusion technique and minimal inhibitory concentration (MIC). Different extracts reveal variable results against the microorganism under study. All extracts have no antibacterial potency for Mycoplasma gallisepticum except Psidium guajava . The results of minimal inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) of the extracts against the six bacteria ranged from 625 to 5000 μg/ml. The used herbal extract could inhibit the selected microorganism under study with variable minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).

Many integrated fish farms depend on the application of poultry droppings/litter which served as a direct feed for the fish and also acted as pond fertilizers. The application of untreated poultry manure exerts an additional pressure on the microbial world of the fish's environment. Aeromonas species are one of the common bacteria that infect both fish and chicken. The aim of this study was to compare the phenotypic traits and genetic relatedness of aeromonads isolated from two diverse hosts (terrestrial and aquatic), and to investigate if untreated manure possibly enhances Aeromonas dissemination among cohabitant fish with special reference to virulence genes and antibiotic resistant traits.

The present study was designed to assess the possible causes of the mass mortalities of Nile Tilapia Oreochromis niloticus at El-Behera Governorate, Egypt, in relationship to environmental and microbiotic factors. Water samples were collected from fish farms at different locations and from Lake Edku to analyze water temperature, water pH, salinity, biological oxygen demand, dissolved oxygen, total ammonia nitrogen, and un-ionized ammonia. A number of moribund and freshly dead fish were sampled and submitted to our laboratory for microbiological, molecular, and histopathological examination. Water analysis of the fish farms revealed noticeable increases in the previously mentioned physicochemical parameters. Clinical examinations of moribund fish showed severe gill rot and massive external and internal hemorrhages. Ordinary and molecular laboratory findings confirmed the presence of Branchiomyces sp. in gill tissue and mixed bacterial fish pathogens (Streptococcus agalactiae, Vibrio alginolyticus, V. parahaemolyticus, Pseudomonas anguilliseptica, and P. aeruginosa) in visceral organs. The histopathological and transmission electron microscopic examinations revealed severe necrosis of gill filaments and blockage of branchial blood vessels and lamellar capillaries with Branchiomyces sp. hyphae and spores mixed with different shapes of bacteria. Severe inflammations were detected in liver, kidney, heart, and brain tissues. Ultimately, we can conclude that the syndrome of mass fish kills in this area is a consequence of ecological damage to the aquatic environment, which is mainly related to natural and anthropogenic factors, as well as to the presence of infectious agents. Received September 30, 2015; accepted April 12, 2016.

Calf diarrhea is one of the major health challenges in cattle herds. The bacteriological examination of fecal samples collected from apparently healthy and diarrheic calves' revealed isolation of 26 E. coli isolates out of 56 calves with an incidence of 46.4%. Serogroups O1, O26, O44, O55, O115, O119, O125, O146, and O151 were identified from the collected fecal samples. Using PCR all isolates was positive for ompA gene species specific for E. coli . While stx 1 and eae A genes detected with incidence of 3.8 and 19.2% respectively from the isolates. The presence of stx 2 gene was negative in the fecal isolates. Among colostrum samples 4 E. coli isolates were detected and serogrouped to O26, O55 and O119. They were negative for eae A, stx 1 and stx 2 except strain number 4 (O55) was positive for stx 1. E. coli strains were sensitive to norfloxacin (80.7%) and resistant to ampicillin and cefotaxime (100% each). Based on our findings, there was no association between occurrence of E. coli and age of calf (2–14 days), while bottle feeding calf colostrum may be a source of E. coli contamination.

Mycoplasma gallisepticum ( MG ) is a worldwide ruined bacteria affecting different avian species, causing severe economic losses. Consequently, the current research sought to detect the incidence of MG among different commercial broiler, layer chickens and turkey farms, and environmental litter samples in different Egyptian governorates (Damietta, Giza, El-Qalyobia, El-Sharqia, and El-Behera) from January 2019 to December 2020. Four hundred samples (infraorbital sinus aspirates, tracheal swabs, serum from diseased birds, and organ samples; lung tissues, air sacs and tracheal bifurcation from freshly dead birds), and environmental samples (litter) were collected for MG isolation. Samples were subjected to phenotypic and molecular identification. Positive bacteriological samples were subjected for molecular identification using polymerase chain reaction ( PCR ) test to detect MG, then sequencing for PCR amplicon of mgc 2 gene. Out of 332 samples subjected for bacteriological examination, 206 were bacteriologically positive for MG with an incidence of 62%. The highest incidence of MG was detected in turkey farms at a rate of 83%, followed by broiler chicken farms, layer chicken farms and litter samples at a percentage of 70, 40, and 40, respectively. The highest prevalence of MG in chickens and turkey was recorded during the winter and autumn seasons. Molecular identification of MG isolates revealed that 85% of isolates were positive for mgc 2 gene using PCR. The Four sequenced strains in this study are closely related and placed in one group with the vaccine strain 6/85 and ts11 strain.