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The impacts of Hg 2+ , Cd 2+ and Zn 2+ on the activities of periplasmic nitrate reductase (NAP) and dehydrogenase (DHA) enzymes of three organisms isolated from soil and sediment-water interface were analysed in liquid culture studies. NAP and DHA activities were estimated from nitrite and triphenyl formazan produced respectively after 4h incubation at 28 ± 2 o C. Hg 2+ completely inhibited NAP activity in Escherichia and Pseudomonas spp. at all the concentrations (0.2 -1mM) while progressive inhibitions of NAP activity were observed in Escherichia and Pseudomonas spp. with increasing concentrations of Zn 2+ and Cd 2+ . Both metals were stimulatory to NAP of Acinetobacter sp. at 0.2 -1mM. Apart from stimulation of DHA activity by Zn 2+ (0.2 -1mM) in Escherichia sp., Cd 2+ (0.4 -1.0mM) in Acinetobacter sp. and (1.0mM) in Pseudomonas sp., all the metals progressively inhibited DHA activities in the three organisms. In Escherichia sp., the activities of the two enzymes were negatively correlated on exposure to Zn 2+ (r = -0.91) and positively correlated (r = >0.90) on exposure to Cd 2+ and Hg 2+ . Based on IC 50 values of the metals for the DHA and NAP enzymes, the most resistant of the three organisms were Escherichia sp. and Acinetobacter sp. respectively. Quantitatively, NAP with its lower IC 50 values than DHA was a more sensitive toxicity measure for Hg 2+ in all the organisms. The sensitivity of microbial metabolic enzymes to the toxic effects of metals varies with the type of enzyme, metal and the microorganism involved. Keywords: Periplasmic nitrate reductase; Dehydrogenase; Escherichia sp.; Pseudomonas sp.; Acinetobacter sp.; IC 50 ; Hg 2+ ; Cd 2+ and Zn 2+ . Palavras-chave: Reductase do nitrato periplásmico; dehidrogenase; Escherichia sp; Pseudomonas sp; de Acinetobactéria sp; IC 50 ; Hg 2+ ; Cd 2 + e Zn 2+ .

Staphylococcus aureus is a major bacterial pathogen that causes different community and hospital-acquired infections. S. aureus resistant to methicillin has become a big and expanding problem of concern in many developing countries. Clindamycin has also been discovered to be a preferred therapeutic alternative for the treatment of both methicillin susceptible and resistant staphylococcal infections. This study examined the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples of patients in Abia state, Nigeria using standard recommended procedures. A total of 750 clinical specimens of blood and urine samples, wound, ear, nasal, high vaginal and ear swabs were collected from three major health facilities in Abia state, Nigeria. Each sample was cultured for bacterial isolates and examined for colonial and cellular morphology while biochemical identification was performed. Antimicrobial susceptibility test was performed on Mueller-Hinton agar (MHA) by disc diffusion method and MRSA screening was done using cefoxitin disc.  A total of 265 (35.3%) S. aureus isolates were recovered, out of which 126(47.5%) were from males and 139(52.5%) were from females, however there was no association between the prevalence and gender (p-value = 0.05) and also prevalence and age (p-value = 0.52). Of the 265 S. aureus isolates recovered, 164(61.9%) were MRSA. All 100% of the MRSA were susceptible to vancomycin, 120(73.2%) to clindamycin, 92(56.1%) to gentamycin. All 100% were resistant to ceftazidine, 157(95.7%) to cloxacillin, 146(89.0%) to augmentin, 136(82.9%) to ceftriaxone and 103(61.6%) to erythromycin. The MRSA strains showed much higher resistance rate than their MSSA counterparts to all tested antibiotic except clindamycin. 64(39.0%) of the MRSA were resistant to 4 classes of antibiotics indicating multi drug resistance (MDR). The overall prevalence of inducible clindamycin resistance among methicillin resistant isolates was 29(17.7%). This implies that 17.7% could have been misidentified as clindamycin susceptible by Kirby-Bauer disk diffusion method. In conclusion prevalence of MRSA was high and it is important to routinely carry out the D-test for detection of inducible clindamycin resistance if clindamycin is considered as a treatment option.

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Gas flaring causes pollution to the environment and also affects the human organs such as the liver and kidneys. The present study seeks to investigate changes in liver, kidney function and atherogenic predictor indices of native women of Ebocha, Niger Delta, Nigeria who have over the years been chronically exposed to the persistent gas flaring in the area. Two hundred (200) healthy and freely consented women aged between 30 to 50 years were recruited; one hundred (100) from Ebocha and one hundred (100) from Uturu the control station. Results revealed that the values of serum activities of alanine aminotransferase (ALT), aspartate transferase (AST) alkaline phosphatase (ALP), and the concentrations of albumin and total protein were significantly (p<0.05) higher in Ebocha women when compared to values of women from Uturu. The pollution caused as a result of gas flaring did not affect the concentrations of bilirubin in women from both sites. However, serum creatinine, urea, K+, Na+, Cl- and HCO3-concentrations were significantly (p<0.05) higher in Ebocha women when compared to values for women from the control station. Ebocha women had significantly (p<0.05) reduced concentrations of serum triglyceride, total cholesterol and HDL cholesterol but significantly (p<0.05) increased LDL-cholesterol and atherogenic predictor indices in comparison with those from Uturu indicating that chronic gas flaring has negative effects on the liver, renal function, lipid profile and atherogenic predictor indices of women resident in Ebocha. Liver, kidney, atherogenic indices, gas flaring, women, Niger Delta.