Habib Bokhari

Uptake of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) by river water fish: The case of River Chenab

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in eleven edible fish species (5 herbivorous and 6 carnivorous) collected from the River Chenab, Pakistan, during 2007-2009. Total OCP and PCB concentrations (ng g(-1) wet weight, ww) ranged between 13-107 (mean: 38) and 3.1-93.7 (mean: 20) for five herbivorous fish species and 21.6-365 (mean: 148) and 2.5-108 (mean: 30) for six carnivorous species, respectively. The trends of detected organochlorine pesticides (OCPs) in fish samples were: DDTs>PCBs>chlordanes>HCHs. The mean concentration(s) (ng g(-1) ww) of OCPs were relatively higher in all fish species collected near industrial areas followed by urban and agricultural areas. Risk assessment of OCPs and PCBs indicated that fish intake may pose health risk to humans with a consumption rate of >8 g/person/day. The hazardous ratios for the 50th and 95th percentile data of OCPs and PCBs in fish exceeded the value of 1, suggesting that the daily exposure to OCPs and PCBs yield a lifetime cancer risk greater than 1 in 10,000.

Avian feathers as a non-destructive bio-monitoring tool of trace metals signatures: A case study from severely contaminated areas

The concentrations of trace metals were assessed using feathers of cattle egrets (Bubulcus ibis), collected within two industrial areas of Pakistan, Lahore and Sialkot. We found, in order of descending concentration: Zinc (Zn), Iron (Fe), Nickel (Ni), Copper (Cu), Cadmium (Cd), and Manganese (Mn), Chromium (Cr), Arsenic (As), and Lithium (Li), without any significant difference (except Fe, Zn, and Ni) between the two areas. The concentrations of trace metals, we recorded were among the highest ever reported in the feathers of avian species worldwide. The concentrations of Cr, Pb, Cd were above the threshold that affects bird reproductive success. The high contamination by heavy metals in the two areas is due to anthropogenic activities as well to natural ones (for As and Fe). The bioaccumulation ratios in eggs and feathers of the cattle egret, their prey, and the sediments from their foraging habitats, confirmed that avian feathers are a convenient and non-destructive sampling tool for the metal contamination. The results of this study will contribute to the environmental management of the Lahore and Sialkot industrial areas.

Mapping human health risks from exposure to trace metal contamination of drinking water sources in Pakistan

The consumption of contaminated drinking water is one of the major causes of mortality and many severe diseases in developing countries. The principal drinking water sources in Pakistan, i.e. ground and surface water, are subject to geogenic and anthropogenic trace metal contamination. However, water quality monitoring activities have been limited to a few administrative areas and a nationwide human health risk assessment from trace metal exposure is lacking. Using geographically weighted regression (GWR) and eight relevant spatial predictors, we calculated nationwide human health risk maps by predicting the concentration of 10 trace metals in the drinking water sources of Pakistan and comparing them to guideline values. GWR incorporated local variations of trace metal concentrations into prediction models and hence mitigated effects of large distances between sampled districts due to data scarcity. Predicted concentrations mostly exhibited high accuracy and low uncertainty, and were in good agreement with observed concentrations. Concentrations for Central Pakistan were predicted with higher accuracy than for the North and South. A maximum 150-200 fold exceedance of guideline values was observed for predicted cadmium concentrations in ground water and arsenic concentrations in surface water. In more than 53% (4 and 100% for the lower and upper boundaries of 95% confidence interval (CI)) of the total area of Pakistan, the drinking water was predicted to be at risk of contamination from arsenic, chromium, iron, nickel and lead. The area with elevated risks is inhabited by more than 74 million (8 and 172 million for the lower and upper boundaries of 95% CI) people. Although these predictions require further validation by field monitoring, the results can inform disease mitigation and water resources management regarding potential hot spots.

Bioaccumulation of nickel by E. sativa and role of plant growth promoting rhizobacteria (PGPRs) under nickel stress.

Phytoremediation potential of plants can be enhanced in association with microbes. Further, many plant growth-promoting rhizobacteria can improve growth under stress. The present study was conducted to investigate the effect of Pseudomonas putida (P. putida) on nickel (Ni) uptake and on growth of Eruca sativa (E. sativa). Three different levels of Ni (low; 150 ug/g, medium; 250 ug/g and high; 500 ug/g) were applied to the soil containing E. sativa seedlings, with or without P. putida. Ni-toxicity was measured by metamorphic parameters including shoot length, root length, biomass, chlorophyll and proline and Ni contents. Inoculation with P. putida increased 34% and 41% in root and shoot length and 38% and 24% in fresh, dry weight respectively, as compared to non-inoculated plants. Similarly, Ni uptake increased by up to 46% following P. putida inoculation as compared to non-inoculated plants. Indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase (ACCD) activity in the growing media enhanced growth and Ni uptake in E. sativa. The present results offer insight on Plant Growth Promoting Rhizobacteria (PGPR), such as P. putida, for the potential to enhance the plant growth by inhibiting the adverse effects of Ni in E. sativa.

Genomic Epidemiology of Vibrio cholerae O1 Associated with Floods, Pakistan, 2010

At least 2 subclades coexisted that had different antimicrobial-resistance profiles and patterns of spread.

A new hybrid agent-based modeling & simulation decision support system for breast cancer data analysis

In this paper, we present a novel technique of building hybrid decision support systems which integrates traditional decision support systems with agent based models for use in breast cancer analysis for better prediction and recommendation. Our system is based on using queries from data (converted to a standardized electronic template) to provide for simulation variables in an agent-based model. The goal is to develop an ICT tool to assist non-specialist biologist researcher users in performing analysis of large amounts of data by applying simple simulation techniques. To demonstrate the effectiveness of this novel decision support system, an extensive breast cancer data collection exercise was carried out with the support of Hospitals in a previously unexplored region. The collected data was subsequently integrated in an electronic medical record filing system for patients. We also demonstrate the application of agent based modeling and simulation techniques for building simulation models of tumor growth and treatment. Our proposed decision support system also provides a comprehensive query tool which facilitates the use of retrieved data in statistical tools2 for subsequent interpretation and analysis.

Antibacterial, Structural and Optical Characterization of Mechano-Chemically Prepared ZnO Nanoparticles.

Structural investigations, optical properties and antibacterial performance of the pure Zinc Oxide (ZnO) nanoparticles (NPs) synthesized by mechano-chemical method are presented. The morphology, dimensions and crystallinity of the ZnO NPs were controlled by tweaking the mechanical agitation of the mixture and subsequent thermal treatment. ZnO nanoparticles in small (< 20 nm) dimensions with spherical morphology and narrow size distribution were successfully obtained after treating the mechano-chemically prepared samples at 250°C. However, higher temperature treatments produced larger particles. TEM, XRD and UV-Vis spectroscopy results suggested crystalline and phase pure ZnO. The NPs demonstrated promising antibacterial activity against Gram negative foodborne and waterborne bacterial pathogens i.e. Enteropathogenic E. coli (EPEC), Campylobacter jejuni and Vibrio cholerae as well as Gram positive methicillin resistant Staphylococcus aureus (MRSA), thus potential for medical applications. Scanning electron microscopy and survival assay indicated that most probably ZnO nanoparticles cause changes in cellular morphology which eventually causes bacterial cell death.

Whooping cough in Pakistan: Bordetella pertussis vs Bordetella parapertussis in 2005–2009

Abstract Pertussis, or whooping cough, is an acute respiratory disease mainly affecting infants and children and is caused by Bordetella pertussis and Bordetella parapertussis. The aim of this study was to investigate the share of Bordetella species from potential whooping cough cases during 2005–2009. Eight hundred and two samples from suspected pertussis cases were collected, mainly from 2 provinces of Pakistan. Bacterial culture, identification, DNA extraction and routinely used polymerase chain reaction (PCR) methods using IS1001, IS1002 and IS481 were used to identify the Bordetella species. The results were unexpected, because all of the isolates collected from the different cities were identified as B. parapertussis (7.4%); B. pertussis was not isolated from any sample. However, PCR results indicated the presence of a small percentage (0.6%) of B. pertussis among the total cases studied. This study suggests that vaccines to protect against both B. pertussis and B. parapertussis should be considered.

Cefazolin loaded chitosan nanoparticles to cure multi drug resistant Gram-negative pathogens

Antibiotic resistance against Gram-negative microbes is considered as an alarming phenomenon that needs to be addressed urgently to develop better therapeutic solutions. The aim of the present research work was to investigate and develop cefazolin loaded chitosan nanoparticles (CSNPs) as a potential tool against multidrug resistant pathogens. Empty and drug loaded CSNPs were prepared by ionic gelation method. It was observed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) based studies that CSNPs were less than 100 nm in size and displayed homogeneity both in shape and size. Encapsulation of cefazolin has not increased the size of nano systems. Zeta sizer results revealed that both systems have positive zeta potential of more or less +50 mV, thus contributing towards a stable formulation. Encapsulation efficiency was directly proportional to the increase in the concentration of antibiotic (28-62%). Furthermore, growth kinetics study had demonstrated excellent antimicrobial potential of cefazolin loaded CSNPs against multi drug resistant Klebsiella pneumoniae, Pseudomonas aeroginosa and Extended Spectrum Beta Lactamase (ESBL) positive Escherichia coli.

Virulence factors profile of drug-resistant Escherichia coli isolates from urinary tract infections in Punjab, Pakistan

Escherichia coli is considered to be the main causative agent of urinary tract infections (UTIs). The primary objective of this study was to investigate the spectrum of five virulence factors among drug-resistant clinical E. coli isolates associated with pyelonephritis and cystitis. A total of 101 samples were positive for E. coli (42 from pyelonephritis cases and 59 from cystitis cases) out of 457 urine samples of patients. Among toxins, haemolysin and secreted autotransporter toxin are found more frequently in isolates causing pyelonephritis (p < 0.020) than cystitis (p < 0.083). The frequent occurrence of P-pili, S-fimbria and protein involved in intestinal colonisation was noted among E. coli isolates associated with pyelonephritis. Overall, the study suggests that clinical isolates associated with pyelonephritis are more virulent than those associated with cystitis and diversified association with various antimicrobial resistance phenotypes was noted.