Acinetobacter baumannii has been an important nosocomial pathogen causing infections in immunocompromised and hospitalized patients. Multiple antibiotic resistant A. baumannii isolates are spreading and causing outbreaks globally. The present study was done to assess the prevalence of antibiotic resistance pattern of A. baumannii isolated from leafy vegetable samples from different retail markets and clinical strains collected from Gondar University Hospital. Among the 13(48.1%) vegetables and 14(51.9%) clinical isolates, the highest Acinetobacter baumannii was detected in cauliflower 6/27 (22.2%). A. baumannii isolates harbored the highest prevalence of resistance against 23 antibiotics including the following carbapenem antibiotics, meropenem (97%), imipenem (99%), ertapenem (94%), doripeneme (96.6%). Comparison of antibiotic susceptibility rate between the vegetable and clinical isolates based on one-way A nova test (P=0.93>0.05) confirmed multiple antibiotic resistance (MDR). Phylogenetic tree determined the relationship of the vegetable isolates, and the clinical isolates were coherent each other. PCR analysis result of 9 representative isolates demonstrated 100% of them harbor resistance determinants (bla OXA23), (88.8%) of them harbor resistance determinants ompA, 100% harbor resistance determinants blaOXA51 and 100% harbor resistance determinants ISAab1. Furthermore, plasmid extraction analysis for 21 representative isolates confirmed that all the isolates harbor at least one plasmid.
In many developing countries, the role of Microbiologically Influenced Corrosion (MIC) is still limited especially in transporting pipelines because an abiotic mechanism can be invoked to explain the observed corrosion. A research on the role of microorganisms in oil transporting pipelines in Escravos gas plant, Delta state, Nigeria was conducted. The microbial count was assayed using pour plate method after which the identification of sulfate-reducing bacteria (SRB), total heterotrophic bacterial, and fungal counts were also carried out. The corrosion rates were determined by the weight loss method. The sulfate-reducing bacteria, total heterotrophic bacterial and fungal counts of the biofilm samples ranged from 4.81 × 103 to 8.56 × 103 CFU/ml, 1.22 × 104 to 2.60 × 104 CFU/ml, and 4.14 × 103 to 8.52 × 103 CFU/ml respectively. The results revealed Desulfovibrio magneticus, Desulfobulbus propionicus, and Desulfuromonas acetoxidans as sulfate-reducing bacteria present. The bacteria species identified isolates include gram-positive Bacillus subtilis, Bacillus cerus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Halomonas subglaciescola while the identified gram negative organisms include Klebsiella oxytoca and Seratia marcescen. The fungal isolates include members of the genus Microsporum, Saccharomyces, Aspergillus, Fusarium, and Verticillium. The weight-loss method was used to determine the rate of corrosion and the mean values of corrosion rates in each pipeline ST1, ST2, ST3, ST4, and ST5 had corrosion rates of 4.47, 3.28, 4.22, 2.56, and 3.19mpy respectively. These results will therefore alert oil companies, the government, and other agencies of the possible microbiologically influenced corroding effects on pipelines.
Fresh fruits and vegetables are an essential part of people's diet all over the world. Since they are typically eaten raw and often without heat treatment or thorough washing, so they serve as vectors for the transmission of pathogenic micro-organisms associated with human diseases. This study aimed at isolating and identifying the pathogenic bacteria from selected popular fresh fruits and vegetables which are known as street food. A total of 7 fresh fruits and vegetables were collected from different open markets of Chittagong with aseptic condition. Selective and non-selective media were used to isolate and enumerate the bacteria. All the species were identified on the basis of morphology, biochemical tests (IMViC) and selective differential culture media. Among the samples Vibrio spp., Lactobacillus spp., Pseudomonas spp. and Salmonella spp. were dominant. All of fresh fruits and vegetables were heavily contaminated with coliform and fecal coliform (> 1100 CFU/100ml). Range of microbial count of guava was 2.1×104 CFU/ml, apple was 4.3×104 CFU/ml, tomato was 8.2×104 CFU/ml, cucumber was 5.0×104 CFU/ml, carrot was 1.3× ×104 CFU/ml, hog plum (Amra) was 7.5×104 CFU/ml. This results indicated that the serious concern for the people of Chittagong area as it can be a great risk for human health. So this results, suggested the necessity to create awareness about hygienic practices in selling and buying fresh fruits and vegetables.
The toxicities of some metal ions (Pb2+, Cd2+, Ni2+, Zn2+, Co2+ as individuals and in quaternary and quinary mixtures with Sodium Dodecyl Sulfate (SDS) to Serratia marcescens (SerEW01) isolated from Otamiri river, Owerri, Imo State, Nigeria were assessed, using dehydrogenase activity as an endpoint. The EC50S observed ranged from 0.046 ± 0.003 mM for Zn2+ to 2.329 ± 0.092 mM for SDS and Duncan tests indicated that the EC50S of the toxicants were significantly different from each other. Among the individual toxicants, the increasing toxicities ranking were SDS> Pb2+> Ni2+> Co2+> Cd2+> Zn2+. The responses of the bacterium to the toxicities of the toxicants were dose-dependent, and the toxicants also progressively inhibited the dehydrogenase activity as the concentration increased. Fixed ratio mixtures (Arbitrary concentration ratio (ABCR) and equieffect concentration ratio (EECR) mixtures) were designed to evaluate the combined toxicities of these toxicants. All the dose-response relationships of the ABCR and EECR mixtures and the individual toxicants could be described by 2-parameter logistic function. All quaternary and quinary mixtures were strongly synergistic against the organisms. Within each mixture ratio, experimental, CA and IA-predicted EC50S were statistically different from one another for both mixtures. The quinary mixtures were generally more toxic to the bacterium than the quaternary mixtures. Both CA and IA models greatly underestimated the toxicities of the quaternary and quinary mixtures against S. marcescens (SerEW01). The synergistic effects of the both the quaternary and quinary mixtures of the toxicants indicates potential deleterious effects of the mixtures to the aquatic bacteria of the river.
Uncontrolled fermentation is a method of transformation which can expose food to risks of contamination by moulds and mycotoxins. Food contaminations represent a potential threat to the health of consumers. In the far North of Cameroun, Iassa obtained by spontaneous fermentation of Hibiscus sabdariffa grains belongs to this food category. This study was aimed at preserving the safety quality of Iassa against fungal growth during fermentation by using lactic acid bacteria (LAB). To carry out this work, moulds and LAB were first isolated from Iassa samples collected in the locality of Gamboura (Cameroon). This was followed by the production of Iassa at the laboratory which was inoculated with moulds and LAB, and the entire batch was left to ferment for 120 hours at 25°C. The antifungal activity of LAB and titratable acidity were evaluated during fermentation. The results showed that, Iassa is a favourable food to the development of moulds. High contamination of this product by moulds of the genus Aspergillus and Fusarium were observed. Generally, this contamination ranged from 2.9Log10CFU/g to 6.9Log10CFU/g. Among the isolated LAB, Lactobacillus brevis and Lactobacillus paracasei were identified as the best LAB with good antifungal activity. Lactobacillusbrevisinhibited completely the growth of Aspergillus in Iassa after 96 hours of fermentation. During this assay, a high growth of Lactobacillus brevis varying between 12.0 and 13.3 Log10CFU/g was also observed. Unlike Lactobacillus brevis, Lactobacillus paracasei produced a high quantity of acidity evaluated at 0.9%. From this work, these bacteria can be used as a LAB starter to ensure safety of the Iassa against moulds after 96 hours of fermentation.
