Isolation and identification of bacteria from marine market fish Scomberomorus guttatus (Bloch and Schneider, 1801) from Madurai district, Tamil Nadu, India
Abstract The present study was conducted to evaluate the hygienic quality and freshness of fish Indo-pacific King Mackerel “Scomberomorus guttatus” through the investigation of the occurrence of bacteria which is an indicator for fish quality. Fishes were collected every fortnight from Madurai fish market on monthly twice of January 2014 to March 2014. Skin surface of the fish was examined. Escherichia coli, Proteus vulgaris, Bacillus subtilis, Klebsiella pneumonia, Pseudomonas aeruginosa and Staphylococcus aureus were identified by Biochemical tests (IMViC Tests). Among the six bacterial species E. coli and K. pneumonia were found in all the collected samples where as other bacterial species were not found. The result of this study revealed that raw fish sold in Madurai fish market has high contamination so the presence of the bacterial species has strongly suggested the urgent need to improve the quality control systems in Madurai fish market.
Antibacterial Susceptibility Pattern of Bacteria Isolated from Retail Fish in Okada, Edo State Nigeria
This study aimed at the microbiological analysis of retail frozen and smoked fish in Okada Edo state Nigeria. Four different retail fish samples were collected from different point of sale in Okada market. Two fresh iced and smoked samples respectively were used for the study. After sub culturing prepared samples into appropriate media, 38 bacterial isolates were obtained from primary culture plates and characterized using standard microbiological methods. Antimicrobial susceptibility tests were performed on the isolates using the Kirby-Bauer disc diffusion method. All the isolates obtained were Gram positive cocci bacteria and had a probable identity of Streptococcus sp, Staphylococcus sp and Coagulase negative Staphylococcus sp. The fresh fish samples had a minimum viable count of 1.7x 106 cfu/g and a maximum count of 4x 106 cfu/g while the smoked fish samples had a minimum viable count of 1.8x 106 cfu/g and a maximum count of 8.5x 106 cfu/g. Results from this study shows that the samples do not meet the acceptable limit (5x 105 cfu/g) of the International Commission of Microbiological Specification for Food (ICMSF). The antibiotic susceptibility test showed the presence of antibiotic resistant organisms among the retail fish samples. The detection of high viable counts of bacteria isolates beyond acceptable limits and their antibiotic resistance pattern elucidates the need for continuous monitoring of retail sea foods in the environment. Prudent use of antibiotics in aquaculture should be promoted to avoid the public health impact caused by antibiotic resistance transferred from retail sea foods to humans.
Germination ecology of Central Asian Stipa spp: differences among species, seed provenances, and the importance of field studies
Stipa-species are wide-spread in Central Asia, but sexual reproduction in the dry steppes is rare. To facilitate conservation and restoration of these important rangelands, we studied germination characteristics of three common Mongolian Stipa-species under field- and lab conditions. Seeds of Stipa krylovii, Stipa gobica and Stipa glareosa were sown at the study site in Southern Mongolia over two consecutive years during which period tests were carried out to ascertain whether competition or herbivory are the main constraints of seedling establishment. In addition, we tested germination and seed viability in the laboratory under two different temperature regimes (20/10°C and 8/4°C), as well as the effect of cold-stratification. The lab experiments also included S. krylovii seeds originating from three climatically different provenances. None of the three Stipa-species seedlings emerged during the first 2 years of the field study. However, after an unusually intense rain event in the third year, 3% of S. krylovii, 0.6% of S. glareosa and 0.1% of S. gobica seeds germinated in the study plots. The factors ‘sowing-year’ and ‘vegetation’ significantly affected seedling emergence, whereas grazing had no effect at all. Under laboratory conditions a high percentage of viable seeds of S. gobica and S. glareosa germinated at both incubation temperatures, and cold-stratification had no effect on germination or viability. Germination of S. krylovii seeds required warmer temperatures and cold-stratification had a positive effect. Such evidence for dormancy was more pronounced in seeds from the moister, northern provenances. Germination of Stipa-species in the field is rare and only possible under exceptionally moist conditions. Conservation should thus concentrate on steppe conservation rather than on restoration. Where artificial reseeding is necessary, differences among species and also among different seed provenances should be taken into account.