A cross-sectional study was conducted at National Avian Disease Investigation Laboratory, Chitwan to determine antibiogram of Escherichia coli isolated from avian colibacillosis cases of broilers and layers in Chitwan. One hundred and sixty (95 from broilers and 65 from layers) liver samples were collected aseptically during postmortem. Samples were taken purposively from dead birds showing lesions perihepatitis, pericarditis, air-saculitis, omphalitis and egg peritonitis. Isolation and identification were made by examination of cultural characteristics of E. coli in MacConkey’s agar, Eosin methylene blue (EMB) agar, Gram’s staining and biochemical tests. Antibiogram of identified E. coli isolate was evaluated against six antibiotics of six different groups by disk diffusion method following CLSI guidelines. One hundred and three E. coliisolates (73 from broilers and 30 from layers) were isolated from one hundred and sixty samples. Highest resistance was observed against Ampicillin (100%) followed by Co-trimoxazole (86.40%), Doxycycline (46.60%), Levofloxacin (45.63%), Nitrofurantoin (26.21%) and Amikacin (10.68%). Nearly about all (96.12%) isolates from 103 isolated E. coli isolates showed multidrugs resistance to two or more than two antimicrobials. All multidrug resistance isolates showed 16 different patterns with each isolate being resistance to at least two drugs. The multiple antibiotic resistance indexing ranged from 0.2 to 0.8 and proportion of isolates with MAR index greater than 0.2 was 96.12%. Int. J. Appl. Sci. Biotechnol. Vol 8(1): 52-60  

Background Staphylococcus aureus is a global public health issue in both community and hospital settings. Management of methicillin-resistant S. aureus (MRSA) infections are tough owing to its resistance to many antibiotics. Macrolide-lincosamide-streptogramin B (MLSB) antibiotics are commonly used for the management of MRSA. This study was aimed to determine the occurrence of inducible clindamycin- and methicillin-resistant S. aureus at a tertiary care hospital in Kathmandu, Nepal. Methods A total of 1027 clinical samples were processed following standard laboratory procedures and antibiotic susceptibility testing of S. aureus was performed by disc diffusion method. MRSA isolates were detected phenotypically using cefoxitin disc, and inducible clindamycin resistance was detected phenotypically using the D-zone test. Results Of 1027 samples, 321 (31.2%) were culture positive, of which 38 (11.8%) were S. aureus. All S. aureus isolates were susceptible to vancomycin, and 25 (67%) of S. aureus isolates were multidrug-resistant. Similarly, 15 (39.5%) of S. aureus were MRSA and 14 (36.5%) were inducible clindamycin-resistant phenotypes. Conclusion Inducible clindamycin and methicillin resistance were common in S. aureus. This emphasizes that the methicillin resistance test and the D-zone test should be incorporated into the routine antibiotic susceptibility testing in hospital settings.