Mastitis is a serious and economically problem commonly prevalent in most dairy cattle and buffaloes herds. Pseudomonas aeruginosa (P. aeruginosa) is opportunistic pathogens implicated in veterinary disorders including clinical mastitis in buffaloes. This study aimed to investigate the antibiogram pattern and synergistic effect of amikacin and norfloxacin against resistant P. aeruginosa isolates from mastitis origin. In addition, detection of some virulence and antibiotics resistance genes. Out of two hundred buffaloes, sixty (30%) were diagnosed as clinical mastitis according to inflammatory signs and the culture results reveled only 5 (8.3%) were P.aeruginosa. Most of P. aeruginosa exhibited resistance to most antimicrobials classes. Meanwhile, the minimal inhibitory concentration (MIC) for amikacin and norfloxacin is significantly reduced from 64 µg/mL to 1 µg/mL and from 256 µg/mL to 8µg/mL respectively with frictional inhibitory concentration (FIC) index 0.25. Therefore, the FIC index recognized a synergistic activity between amikacin and norfloxacin against all P.areuginosa isolates. The mPCR proved to be an efficient tool for detection of virulence genes (exoT, toxA, oprL, and isaI) at 152, 396, 504, 606 bp respectively. In addition, all the P.aeruginosa were found to carry the resistance genes (qnrS, qnrA, aadB). In conclusion, the combination of norfloxacin plus amikacin suppressed the resistance pattern P. aeruginosa isolates. Therefore, their combination showed synergistic bacterial potential antimicrobial activity in treatment of mastitis due to P. aeruginosa infection and help in reducing the resistance problem.

Mastitis is the most common serious and economical disease affecting the dairy industry. The current study aimed to determine the molecular characterization of K. pneumoniae isolated from buffaloes with clinical mastitis as well as determine the antimicrobial pattern and virulence associated genes. Out of examination one hundred and fifty dairy buffaloes at Beheria governorate, 57 (38%) showed clinical mastitis signs. All samples are submitted to bacteriological examination and confirmed by biochemical tests. The result showed that K.pneumoniae was identified in only five (8.7%). Regarding to the antibiogram profile, K. pneumoniae isolates exhibited high resistance pattern against Carbenicillin, Cefotaxime, Flumequine, Gentamicin, Kanamycin (100%) followed by Neomycin, Nitrofurantoin, Penicillin (80%) and Oxytetracycline, Sulfamethoxazole / trimethoprim (60%). Meanwhile, higher susceptibility to Ampicillin (100%), followed by Chloramphenicol, Colistin Sulphate, Erythromycin, and Streptomycin (80%). Molecular identification using the mPCR approach applied efficiently to detect the K. pneumoniae virulence genes (mrkA, mrkD, iutA) at 475, 226, 300bp respectively. In addition, the successfully detection of blaTEM and blaSHV for β lactams resistance genes at 516 and 392 bp. In conclusion, the phenotypic and genotypic resistance pattern of K. pneumoniae isolates indicates the portability of transmission of resistance genes through milk and food chain with public health concern.

Listeria monocytogenes from Listeria genus, which as saprophytes, but causes systemic infections as pathogenic bacteria. Listeria monocytogenes is widely spread in environment, caused infection of farm animals during fields grazing leading to contamination by wildlife, or manure. There was a close relation between improperly farm environment originated from contaminated crops and listeriosis. It causes animals infection with is not associated with clinical symptoms then the animal is flaking Listeria monocytogenes in feces. Listeria species' identification is a serious to gain the ecological Listeria virulence influence. The samples understudy consisted of animal stool, mattress, ration and water (n = 30) were for each. All samples were exposed to bacterial check. The results obtained that Listeria species was isolated with a general occurrence of 33.3%. The stools had 17.5%, mattress 7.5%, ration 5.0%, and water 3.3%. Meanwhile the occurrence of Listeria monocytogenes was overall 20.0% included (10.0%, 5.0%, 2.5%, and 2.5 %) as the same aforementioned samples. The PCR-technique was applied for detection of Listeria monocytogenes virulence genes using primers groups. Those genes were hlyA (hemolysin A gene), inlA (internalin A), prfA. The results obtained the present of all virulence genes. Listeria monocytogenes susceptibility to antimicrobial agents usually used for farms treatment was determined for animal stools Listeria monocytogenes isolates. The results showed that the generally sensitive rate was 70.0%. The100.0% was sensitive to Ampicillin, Amoxicillin, Erythromycin, and Tetracycline followed by Ofloxacin 75.0%. But the 50.0% was sensitive to Penicillin G, Cephalexin, and Gentamycin, finally Lincomycin ‫الزراعية‬ ‫للعلوم‬ ‫العربية‬ ‫المجلة‬ ‫مج(‬ 5 ‫)،ع‬ ( 55 ) ‫يوليو‬ 2222 ‫م‬ 115 3 was resistant. It was concluded that the Listeria monocytogenes were isolated from understudy samples as noticeable degrees. Also, virulence genes were presented in the isolated Listeria monocytogenes. That powerful proved the attendance of Listeria monocytogenes trendy a hidden contamination in animal farm. So, that could affect the animal health and animal productions. It was recommended that the undertake to follow the "Farm Health Conditions" and follow-up to decrease the microbial contamination. As well fix the animal vaccinations to maintain the animal health and livestock.