The current study was conducted to isolate and identify multidrug-resistant Staphylococcus aureus (MDR-SA) from mastitis milk samples and to determine their antimicrobial susceptibility pattern. A total of 48 bovine mastitis (BM) milk samples were collected from different parts of the Rangpur division, Bangladesh. After the collection of milk samples, mastitis was confirmed using the California mastitis test. Isolation and identification of Staphylococcus aureus were performed using conventional cultural and biochemical tests as well as using molecular methods of PCR. Nucleotide sequence analysis of the 23S rRNA gene of Staphylococcus aureus was determined. The antibiogram of the isolated bacteria was conducted using the disc diffusion method. Phylogenetic analysis of 23S rRNA was done using MEGA 7, ClustalW multiple sequence alignment, and NCBI-BLAST tools, where the sequence of the isolate showed 98% to 99% identity. Antibiogram test using 15 antimicrobial agents showed that all of the Staphylococcus aureus isolates were classified as multidrug-resistant (MDR). It was found that the isolates were resistant to tetracycline, novobiocin, methicillin, vancomycin, and cephradine, and the isolates were sensitive to ciprofloxacin, azithromycin, norfloxacin, levofloxacin, gentamicin, and amoxicillin. The detection of MDR-SA in mastitis milk is alarming and represents a great public health concern. The findings of the present study help identify Staphylococcus aureus at the molecular level using 23S rRNA gene sequencing and will help select the appropriate and effective antimicrobial agent to control BM in the northern part of Bangladesh.

The objective of this study was to identify the multi-drug resistance (MDR) Klebsiella sp. from mastitis milk samples. In the current research, 48 clinical mastitis milk samples were collected from Rangpur division, Bangladesh. Confirmation of bovine mastitis (BM) was done by the California Mastitis Test (CMT). All the CMT positive isolates were subjected for the identification of Klebsiella sp. using through a series of cultural and biochemical tests. MDR Klebsiella sp. isolates were determined using the disk diffusion method, and minimum inhibitory zones were measured by following Clinical and Laboratory Standards Institute. MDR patterns of the isolates were also subjected to study by using housefly (Musca domestica). Among the isolates, 62.5% (n = 30/48) revealed the presence of Klebsiella sp. Eight antimicrobial agents including Amoxicillin, Novobiocin, Erythromycin, Vancomycin, Cephradine, Tetracycline, Bacitracin, Methicillin, and housefly (M. domestica) showed complete resistance to Klebsiella sp. On the other hand, Chloramphenicol, Gentamicin, Ciprofloxacin, Azithromycin, Norfloxacin, Levofloxacin, and Nalidixic acid showed sensitivity. This study helps to treat BM with effective antibiotics and helps in an epidemiological study in Rangpur division as well as helps to create public health awareness.

Salmonella Gallinarum is one of the most important bacterial pathogens associated with diminished egg production in poultry. The aim of this study was to understand the occurrence, molecular traits and antimicrobial resistance patterns of Salmonella Gallinarum strains isolated from small-scale commercial layer flocks with low level biosecurity standards in Bangladesh. A total of 765 samples, including cloacal swabs (535), visceral organs (50), and droppings (180), were collected from chickens of 12 layer flocks in 11 districts. Salmonella Gallinarum was isolated and characterized through culture-based method, followed by biochemical tests, sero-grouping, PCR assays, sequencing, and antibiogram. The identity of biochemically detected isolates of Salmonella Gallinarum was confirmed via genus-specific 16S rRNA gene based PCR, followed by invA and spvC genes based PCR assays. Occurrence of Salmonella Gallinarum was detected in overall 25.75% (197/765) samples, with a significantly (p < 0.05) higher incidence in visceral organs (42%) in comparison to cloacal swab (24%) and droppings (26%). Sequencing and subsequent phylogenetic analysis of invA and spvC genes in representative strains of Salmonella Gallinarum revealed a close genetic lineage, with a sequence similarity of 98.05–99.21% and 97.51–99.45%, respectively, to previously published sequences of the corresponding genes from the same serogroup strains. Remarkably, 66.5% (131/197) of the isolated strains of Salmonella Gallinarum were found to be resistant to 3 to 6 antimicrobial agents, and interpreted as multidrug resistant (MDR). The findings of this study underscore an inherent need of appropriate control measures to curb the widespread incidence of MDR Salmonella Gallinarum in small-scale commercial layer flocks, thereby, facilitating enhanced egg production and further support to the food security and safety in low resource settings.

This study was selected to find out the bacterial pathogens in egg yolk, egg shell, feed and air samples of poultry houses at Dinajpur district in Bangladesh with isolation, identification and characterization of bacterial pathogens present in those samples. For this study, a total of 147 samples comprising egg shell (36), egg yolk (36), feed (45) and air (30) were collected during the period from January to May, 2012 and the collected samples were then examined for the bacteriological study by using cultural, morphological and biochemical techniques. On the basis of their cultural, morphological and biochemical properties the isolated organisms were identified as Escherichia coli, Staphylococcus spp., Salmonella serovars and Bacillus spp. In this study it was observed that out of 147 samples a total of 51 were identified as bacterial pathogens in which egg shell containing 10 (27.78%), egg yolk 11 (30.56%), feed 20 (44.44%) and air 10 (33.33%) respectively. In this study it was also observed that the highest prevalence of bacterial pathogens in feed samples (44.44%) in comparison with egg shell (27.78%), egg yolk (30.56%) and air samples (33.33%). In this study it was demonstrated that out of four (04) pathogens Escherichia coli was more abundant (39.21%) in the layer house and its environment in comparison with Staphylococcus spp. (25.49%), Salmonella (23.52%) and Bacillus spp. (11.76%) respectively.Asian J. Med. Biol. Res. June 2017, 3(2): 168-174

The present study was selected as infectious coryza is one of the major problems affecting poultry industry in the developing country like Bangladesh and the reports regarding infectious coryza are yet not be documented considering epidemiological investigation, proper isolation, identification and pathogenicity study. The epidemic behavior of the etiological agent of this disease were studied based on age, sex, breed, spatial and temporal differences after collection of samples suspected to be infected with infectious coryza in layer chicken of Bangladesh. The incidence rate of infectious coryza from field cases were recorded as per information received from farmers by using a structured questionnaire and also clinical signs and symptoms. The disease was very high in laying hen (18.38%) in Sylhet and growing birds (7.25%) in Khulna in comparing with prelaying stage (2.07%) also in Sylhet region of Bangladesh. In this study no significant differences was observed as their location variation except Sylhet (9.2%) in comparison with other areas (Rangpur – 8.76%, Rajshahi -8.82%, Khulna - 8.83%, Dhaka – 8.72 and Chittagong - 8.65% respectively) of Bangladesh but significant differences was observed as their age group. However, the incidence rate of this disease was found to be very high during winter (8.77%) in compare with summer (0.42%) season. Moreover, during investigation a total of 122 samples were collected from different areas of Bangladesh for the period of March 2011 to February 2014. The higher rate of incidence of A. paragallinarum was found in Sylhet (66.66%) and lowest in Dhaka (43.75%). The association of A. paragallinarum with different seasons revealed that higher incidence rate was found in winter season (52.26%) in comparison with summer season (1.85%). The suspected positive isolates were subjected to experimental pathogenicity study in natural host for there – isolation of A. paragallinarum was done as per Kotch postulates.Asian J. Med. Biol. Res. March 2016, 2(1): 82-94

The present study was conducted to isolate and identify the organisms in butter and cheese manufactured by different plants namely Milk Vita and Quality sold in retail stores at Dinajpur, Bangladesh were collected and transported aseptically to the laboratory for bacteriological analyses. The samples were analyzed to determine the hygienic status of butter and cheeses and also for the total viable count (TVC), presence of gram-positive and gram-negative bacteria. TVC was performed according to the American Public Health Association, using plate count agar medium for TVC and Eosine methylene blue (EMB) agar for total E. coli count and Staphylococcus agar no. 110 for total Staphylococcus count. The average TVC for Milk Vita butter 3.28 x 10⁵ CFU/gm (log 5.5) was lower than local butter 5.45 x 10⁶ CFU/gm (log 6.7) and average TVC for Quality cheese 4.5 x 10⁵ CFU/gm (log 5.7) was lower than local cheese 5.14 x 10⁶CFU/gm (log 6.7). The bacterial loads of butter and cheese samples were within the acceptable limit of public health safety, since the count was well below the acceptable limit. The highest extent of bacterial contamination and proliferation of viable bacteria occurred in local butter and local cheese. The numbers of E. coli in local butter and cheese were little bit higher indicating poor hygienic practices during manufacture, post process contamination and unsatisfactory transportation. Statistically the E. coli were more closely related to TVC than the staphylococcal counts in the samples of Milk Vita butter 2.68 x 10³ CFU/gm (log 3.4), Local butter 3.15x 10⁴ CFU/gm (log 4.5), Quality cheese 4.46 x 10³ CFU/gm (log 3.6) and Local cheese 1.19 x 10⁴ CFU/gm (log 4.0) respectively. The results demonstrated that Milk Vita butter and Quality cheese are of superior quality product in respect of sanitary condition. Asian Australas. J. Biosci. Biotechnol. 2016, 1 (3), 504-513