Staphylococcus species cause diseases in animals and humans. The prevalence and antimicrobial profiles of Staphylococcus spp. in animals and human samples in the Minya Governorate, Egypt, were determined, and resistance- and virulence-associated genes were observed in multidrug-resistant (MDR) isolates. Moreover, the antibacterial effect of carvacrol essential oil (EO) on the MDR isolates was studied. A total of 216 samples were aseptically collected from subclinically mastitic cow’s milk (n = 100), sheep abscesses (n = 25) and humans (n = 91). Out of 216 samples, a total of 154 single Staphylococcus species (71.3%) were isolated. The most frequent bacterial isolates were S. aureus (43%), followed by S. schleiferi (25%), S. intermedius (12%), S. xylosus (12%), S. haemolyticus (4.5%), S. epidermidis (2%) and S. aurecularis (1%). Haemolytic activity and biofilm production were detected in 77 and 47% of isolates, respectively. Antimicrobial susceptibility testing showed a high degree of resistance to the most commonly used antimicrobials in human and veterinary practices. The mecA, vanA, vanC1 and ermC resistance genes were detected in 93, 42, 83 and 13% of isolates, respectively. Moreover, hla, icaA and icaD virulence genes were detected in 50, 75 and 78% of isolates, respectively. Carvacrol effectively inhibited the growth of all tested isolates at concentrations of 0.1, 0.05 and 0.04% while a concentration of 0.03% inhibited 75% of isolates. Interestingly, some phenotypic changes were observed upon treatment with a carvacrol oil concentration of 0.03%. All the treated MDR Staphylococcus isolates changed from multidrug resistant to either susceptible or intermediately susceptible to 2–3 antimicrobials more than parental bacterial isolates. Real-time PCR was applied for the detection of the differential expression of mecA and vanC1 genes before and after treatment with carvacrol which revealed a mild reduction in both genes’ expression after treatment. Staphylococcus spp. Containing MDR genes are more likely to spread between humans and animals. From these results, carvacrol EO is a promising natural alternative to conventional antimicrobials for pathogens impacting human health and agriculture due to its potential antimicrobial effect on MDR pathogens; even in sub-lethal doses, carvacrol EO can affect their phenotypic properties and genes’ expression.

Avian colibacillosis is one of the most important diseases of chickens resulting in significant economic losses as well as high morbidity and mortality. In the current study, the prevalence of avian colibacillosis was studied in different farms of broiler chickens in Beni Suef, EL-Minia, El-Fayoum, Assiut and Sohag Governorates. A total of 300 pooling samples were collected aseptically from heart blood as well as the affected organs including air sacs, pericardial sac, and liver of slaughtered diseased and freshly dead broiler chickens. Bacteriological examination of the collected samples showed that a total number of 80 E. coli isolates were recovered with an overall prevalence of 26.7. The highest prevalence was recorded in El-Fayoum (33.3%) followed by El-Minia (25%), Beni Suef and Assiut (22.5% for each) while the lowest prevalence was in Sohag (17.5%). The in-vitro antimicrobial susceptibility testing revealed that E. coli isolates showed high sensitivity to colistin sulphate only (70%). Meanwhile, high resistances were recorded against other antimicrobials including amoxicillin (97.5%), cefotaxime sodium and florfenicol (95% for each), apramycin, ciprofloxacin and gentamicin (92.5% for each), streptomycin (90%), enrofloxacin (87.5%), trimethoprim-sulphamethoxazol and doxycycline HCl (77.5% for each). All E. coli isolates were MDR (100%). PCR was applied on 10 MDR E. coli isolates to detect the 3 resistance-associated genes (qnrA, tetA and aac(6′)-Ib-cr and 5 virulence-associated genes (iutA, hly, sta, lt and astA). The results showed that all the tested isolates (100%) harbored qnrA, tetA, iutA and astA genes meanwhile aac(6′)-Ib-cr, hly, sta and lt genes were not detected in any isolate.

Staphylococci are one of the most significant causative mastitis pathogens in both clinical and subclinical cases. The present study aimed to study the prevalence of staphylococcal subclinical mastitis studying their antibiogram and detection of the prevalence mecA and blaZ genes in β-lactams resistant isolates using polymerase chain reaction (PCR). A total of433 Staphylococcus species were recovered from 493 subclinically mastitic quarters with a prevalence of 87.8%. S. aureus were the most prevalent isolates as 237 isolates (48%). Also, 196 CNS isolates (39.8%); representing 8 species, were recovered of which S. xylosus was the most predominant (36.7%), followed by S. epidermidis (14.8%), S. chromogenes (13.3%), S. haemolyticus (11.2%) and S. saprophyticus (9.7%). Results of antimicrobial susceptibility testing showed high resistances against ampicillin and cefoxitin while a moderate resistance was recorded against amoxicillin. PCR was applied on 40 β-lactam resistant Staphylococcus isolates (20 S. aureus and 20 CNS) for detection of mecA and blaZ genes. The two genes were detected in 75% and 65% of S. aureus isolates as well as in 70% and 55% of CNS isolates, respectively.

Ascites in poultry is a serious problem for the commercial broiler industry causing great economic losses. In the present study, the prevalence of ascites was studied in 200 broiler chickens. Also, the correlation between ascites and other systemic lesions at the same bird was investigated. Moreover, identification of the causative bacterial agents was conducted focusing on E. coli and Salmonellae isolates. The prevalence rate of ascites in examined broiler chickens was 17%. Ascites without systemic lesion was observed in 10% of birds while 7% of birds had ascites associated with other systemic lesions in the internal organs and hepatitis was the most frequent lesion. The bacteriological examination revealed that out of 49 samples collected, a total of 40 bacterial isolates were recovered (1.6%). Among the recovered isolates, E. coli was the most prevalent isolate (n=19; 47.5%) followed by Salmonella spp. (n=10; 25%), Proteus species (n=8; 20%) and Enterococcus faecalis (n=3; 7.5%). Antibiogram of E. coli isolates showed a high sensitivity against colistin sulphate while they were highly resistant to the other antimicrobials. Meanwhile, Salmonella isolates showed high sensitivities to ciprofloxacin and enrofloxacin while they were highly resistant to the other antimicrobials.

Cellulitis is a serious problem for the poultry industry because of increasedcondemnations, carcass downgrading at processing, and higher labor costs to processaffected flocks. In the present study, the prevalence of cellulitis was studied in 240 broilerchickens. The correlation between cellulitis and other systemic lesions of the same bird wasinvestigated also. Moreover, identification of the causative bacterial agents was conductedfocusing on E. coli and Salmonella isolates. The prevalence rate of cellulitis in examinedbroiler chickens was 38.3%. Cellulitis without systemic lesion was observed in 14.2% ofbirds while 24.2% of birds had cellulitis associated with other systemic lesions in theinternal organs while hepatitis was the most frequent. The bacteriological examinationrevealed that of 253 samples collected, a total of 157 bacterial isolates were recovered(62.1%). Among the recovered isolates, E. coli was the most prevalent (126 isolates; 80.3%)as well as 4 Salmonella species (2.5%), 9 Proteus species (5.7%), 7 Pseudomonasaeruginosa (4.5%), 3 Enterobacter species (1.9%) and 8 Staphylococcus aureus (5.1%).Serogrouping of E. coli isolates revealed that O125 was the most prevalent; 32%, followed byserogroups O158, O55, O78 as 24%, 12%, 10%, respectively, then both O1 and O8; 6% foreach, and finally O15; 4%. Antibiogram of E. coli isolates showed a high sensitivity againstenrofloxacin only (81%) while they were moderately sensitive to apramycin (65.9%) andcolistin sulphate (61.9%) as well as ciprofloxacin and cefotaxime sodium (56.3% and55.6%, respectively). On the other hand, high moderate degrees of resistances wereobserved against the other antimicrobials. Salmonella isolates showed complete sensitivitiesto ciprofloxacin and enrofloxacin while they were completely resistant to most ofantimicrbials.

Bovine respiratory disease (BRD) is the most common and costly diseaseaffecting beef cattle calves in the world. The objectives of this study were to put ahigh light on epidemiology of P. multocida and M. haemolytica as important causesof bovine respiratory disease (BRD) in Egypt Governorates; Giza,El-Fayoum,BeniSuef, Assiut and Sohag. A total number of 406 deep nasal swabs and blood sampleswere collected from 406 bovine calves suffered from respiratory manifestationsreared in different Governorates in Egypt. Bacteriological examination wasachieved and isolation of P. multocida and M. haemolytica were attained. Theoverall prevalence of bothP. multocida and M. haemolytica was of 26.6%; 18.2%for P. multocida and 8.4%for M. haemolytica. EL-Fayoum Governorate showed thehighest prevalences while Beni-Suef Governorate showed the lowest prevalences.P. multocida was singly isolated from 4.9% of cases. While it was mixed with S.aureus, E. coli, Streptococcus spp., both S. aureus and E. coli, both S. aureus andStreptococcus spp. and both E. coli and Streptococcus spp. with percentages of4%, 1.2%, 2.2%, 1.7%, 3.2% and 1.0%, respectively. Meanwhile, M. haemolyticawas isolated as a single isolate from 1.7% of cases while it was mixed with S.aureus, Streptococcus spp., both S. aureus and Streptococcus spp. and both E. coliand Streptococcus spp. with percentages of 2.7%, 1.2%, 2.5% and 0.2%,respectively. In conclusion respiratory manifestations are very important disordersin bovine calves. P. multocida and M.haemolytica are the most common bacteriacausing infection.