Irum Perveen

Prevalence and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci in Rawalpindi, Pakistan.

Methicillin resistant Staphylococcus aureus(MRSA) and methicillin resistant coagulase negative staphylococci (MRCoNS) are the important nosocomial infectious agents. There is a growing concern about the rapid rise in the resistance of Staphylococcus aureusto presently available antimicrobial agents. The aim of this study was to evaluate the prevalence rate of MRSA and MRCoNS and their rate of resistance to different antistaphylococcal antibiotics used broadly for treatment. Out of the total 350 staphylococcal isolates from different clinical specimens 148 isolates (60.40%) were identified as MRSA by oxacillin screen agar method, and 46 isolates (43.80%) were screened as MRCoNS. All the MRSA and MRCoNS isolates were tested for antibiotic resistance pattern by disc diffusion method for 16 different antibiotics. All the isolates of

Heavy metal contamination in water, soil, and milk of the industrial area adjacent to Swan River, Islamabad, Pakistan

ABSTRACT Trace heavy metals such as Cr(III), Ni(II), Cd(II), Zn(II), Pb(II), and Cu(II) are hazardous pollutants and are rich in areas with high anthropogenic activities. Their concentrations were analyzed using atomic absorption spectroscopy, and it was found that their concentrations were several fold higher in downstream Swan River water samples of the Kahuta Industrial Triangle as compared to upstream. Heavy metal soil concentrations taken from the downstream site were 149% for Cr, 131% for Ni, 176% for Cd, 139% for Zn, 224% for Pb, and 182% for Cu when compared to samples from the upstream site. Quantitative analysis concluded that these metals were higher in milk samples collected from downstream as compared to the samples from upstream water-irrigated sites. The order of metal in milk was as Zn > Cr > Cu > Cd > Pb = Ni. Heavy metal contaminations may affect the drinking water quality, food chain, and ecological environment. It was also suggested that the toxicity due to such polluted water, soil, and milk are seriously dangerous to human health in future.

Performance Evaluation of Integrated Constructed Wetland for Domestic Wastewater Treatment.

Simple, budget friendly, laboratory-scale integrated constructed wetland (ICW) was designed to assess domestic wastewater treatment performance at a loading rate of 75 mm/d, planted with native plant species: Veronica-angallis aquatica and compared with non-vegetative control system at various residence times of 4, 8, 12, 16, 20, 24, and 28 days. Results revealed that the vegetated ICW demonstrated superior performance over non-vegetated control: 69.12 vs 17.12%, 67.77 vs 16.04%, 68 vs 16.48%, 71.19 vs 6.56%, 71.54 vs 14.80%, and 72.04 vs 11.41% for total dissolved solids, total suspended solids, phosphates (PO4(-)), sulfate (SO4(-)), nitrate (NO3(-)), and nitrite (NO2(-)), respectively, at 20 days residence times. Reduction in bacterial counts (2.79 × 10(4) CFU/mL) and fecal pathogens (345.5 MPN index/100 mL) was observed in V. aquatica at 20 days residence time. Therefore, the present study highlights not only the presence of vegetation but also appropriate residence time in constructed wetlands for better performances.

Physiological activities associated with biofilm growth in attached and suspended growth bioreactors under aerobic and anaerobic conditions.

This research work evaluated the biofilm succession on stone media and compared the biochemical changes of sludge in attached and suspended biological reactors operated under aerobic and anaerobic conditions. Stones incubated (30 ± 2°C) with activated sludge showed a constant increase in biofilm weight up to the fifth and seventh week time under anaerobic and aerobic conditions, respectively, where after reduction (>80%) the most probable number index of pathogen indicators on ninth week was recorded. Reduction in parameters such as biological oxygen demand (BOD) (47.7%), chemical oxygen demand (COD, 41%), nitrites (60.2%), nitrates (105.5%) and phosphates (58.9%) and increase in dissolved oxygen (176.5%) of sludge were higher in aerobic attached growth reactors as compared with other settings. While, considerable reductions in these values were also observed (BOD, 53.8%; COD, 2.8%; nitrites, 28.6%; nitrates, 31.7%; phosphates, 41.4%) in the suspended growth system under anaerobic conditions. However, higher sulphate removal was observed in suspended (40.9% and 54.9%) as compared with biofilm reactors (28.2% and 29.3%). Six weeks biofilm on the stone media showed maximum physiological activities; thus, the operational conditions should be controlled to keep the biofilm structure similar to six-week-old biofilm, and can be used in fixed biofilm reactors for wastewater treatment.

Hepatitis B seroconversion after vaccination in infants in rural and urban areas of Rawalpindi, Pakistan.

Purpose: This study was designed to evaluate the immunogenicity of hepatitis B vaccine in infants of rural and urban Pakistan and to find out the vaccine efficacy. Methods: A sample of 400 subjects was taken by simple random method from the rural and urban areas (200 from Rural and 200 from urban areas) of Rawalpindi District Pakistan. The serum samples were analyzed by Enzyme Linked Immunosorbant assay (ELISA) for the quantitative determination of antiHBs antibodies. Results: As 88 (22%) infants out of the total 400 were found to be seropositive at baseline. The post vaccination results showed that about 15 (7.53%) of infants had inadequate levels of antibodies (i.e. <10 IU/L). Overall 92.46% infants showed a positive response to the vaccine. The females showed higher titers of antiHBs against vaccination as compared to that of males. Infants Short Research Article Perveen et al.; BJMMR, 5(12): 1557-1561, 2015; Article no.BJMMR.2015.175 1558 of urban areas showed higher titers as compared to that of rural areas. Conclusion: Our results reinforces that the Hepatitis B vaccine has a good tolerability and is highly immunogenic among infants. It is recommended that serosurvey of HBsAg and vaccine coverage at country level should be done.

Studies on Degradation of 7-ketocholesterol by Environmental Bacterial Isolates

Medical bioremediation is a unique strategy of targeting pathogenic compounds with an exogenous enzyme of microbial origin. The objective of this study was to isolate and screen the microorganisms from diverse environmental samples for their ability to catabolize 7-ketocholesterol. Isolation of bacterial strains was performed and molecular identification was carried out by amplification and sequencing of 16S rDNA for 4 the best degrader isolates. Degradation was confirmed on the basis of UV spectrophotometric and HPLC analysis. Four bacterial isolates, showing high catabolic activity towards 7-ketocholesterol were isolated: Alcanivorax jadensis IP4 (accession number KP309836; sea water sediment), Streptomyces auratus IP2 (accession number KP309837; soil), Serratia marcescens IP3 (accession number KP309838; soil) and Thermobifida fusca IP1 (accession number KM677184; manure piles). All the isolates were capable of utilizing 7-ketocholesterol as the sole organic substrate, resulting in its mineralisation. The most rapid degradation was observed with A. jadensis IP4 followed by T. fusca IP1. The degradation was followed and analyzed by HPLC. A. jadensis IP4 removed 7-ketocholesterol below detection levels within 8 days.