Umar F A R O O Q Gaur | Taif University, Kingdom of Saudi Arabia (original) (raw)

Papers by Umar F A R O O Q Gaur

Asian Jr. of Microbiol. Biotech. Env. Sc. Vol. 23, No. (2) : 2021 : 163-174, 2021

Salmonella typhi is a facultative intracellular pathogen of Salmonella serovar that causes typhoi... more Salmonella typhi is a facultative intracellular pathogen of Salmonella serovar that causes typhoid fever in humans (the only known natural hosts and reservoir of infection). Typhoid is one of the major emerging public health problems in developing countries. S. typhi is a motile, non-capsulated, nonsporulating, Gram-negative facultative anaerobic bacillus, having characteristic flagellar, somatic, and outer coat antigens that are susceptible to various antibiotics. Typhoid fever is a systemic disease and without taking care, the illness may last for three to four weeks or death can be possible. Although, the global burden of typhoid fever has reduced, emergence of multidrug resistant S. typhi (MDRST) is still a threat to public health. Currently, 107 strains of this organism have been isolated carrying variable metabolic characteristics, levels of virulence, and multi-drug resistance genes that make the treatment more complicated in the drug resistant regions. The best diagnosis can be attained including cultural characterization on MacConkey and S-S agar, XLD agars, and the bacterium is strictly non-lactose fermenting. The bacteria can be distinguished by no gas production from other Enterobacteriaceae by growing in Triple Sugar Iron agar. Despite the discovery of newer antibacterial drugs, enteric fever has continued to be a major health problem. S. typhi developed resistance to several antibiotics like ampicillin, ceftriaxone, and co-trimoxazole, besides ciprofloxacin is at the developing resistance stage. The emergence of multidrug resistance had made the treatment and management of enteric fever complicated. This has now become the one of the greatest challenges in the treatment and management of this disease.

wjpls, Vol. 7, Issue 4, 153 – 160., 2021

Chronic diseases are now the dominant contributors to the global burden of disease, and CVD is th... more Chronic diseases are now the dominant contributors to the global burden of disease, and CVD is the largest contributor to the chronic disease cluster. Although CVD death rates are declining in most high income countries, trends are increasing in most low and middle income countries. The response-to-injury hypothesis explains atherosclerosis as a chronic inflammatory response to injury of the endothelium, which leads to complex cellular and molecular interactions among cells derived from the endothelium, smooth muscle and several blood cell components. Inflammatory and other stimuli trigger an overproduction of free radicals, which promote peroxidation of lipids in LDL trapped in the subendothelial space. Evidence is presented that natural nano-particle HDL and Omega-3 fatty acids have an antioxidant impact and prevent the peroxidation of lipids and thus are protective against the development of atherosclerosis. Paraoxonase (PON) or arylesterase is a natural nanoparticle HDL associated enzyme that protects LDL as well as HDL from oxidative stress. The present study has shown that the formation of conjugated dienes was significantly decreased by 21.5% and 17.87% with respect to control after adding Omega-3 fatty acids and HDL respectively when LDL isolated from normal subjects was subjected to Cu ++ mediated in vitro oxidative modification whereas this decrease was found to be 13.25 % and 12.82 % respectively when LDL isolated from hyperlipidemic subjects was subjected to oxidation. On the other hand the antioxidant power of plasma isolated from normal subjects increased by 54.28% and of plasma isolated from hyperlipidemic subjects increased by 69.81% after treatment with Omega-3 fatty acids. This increase was found to be 53.57% and 68.68% in plasma isolated from normal and hyperlipidemic subjects respectively, after treatment with HDL .A significant increase was observed in the antioxidant power of LDL also after in vitro treatment with Omega-3 fatty acids being 15.58% in normal subjects and 32.46% in hyperlipidemic subjects. Treatment with HDL also had a similar effect, increasing the antioxidant power of LDL isolated from normal subjects by 13.72% and that from hyperlipidemic subjects by 32.84%. The present study proves both of them effective antioxidants, Therefore, Omega-3 fatty acids can be used as a nutritional supplement to avoid the risk of cardiovascular diseases and natural nano-particle HDL can replace harmful drugs in the treatment of CVD.

Apical membrane antigen-1 (AMA-1) and Duffy binding protein (DBP) of plasmodium vivax are potenti... more Apical membrane antigen-1 (AMA-1) and Duffy binding protein (DBP) of plasmodium vivax are potential vaccine candidate antigens. High degree of polymorphism in the candidate antigens may compromise the efficacy of an otherwise effective vaccine. Polymorphic regions of the genes encoding plasmodium vivax. AMA-1 and DBP were analyzed by PCR-RFLP in 25 north Indian isolates of plasmodium vivax. No size variation was seen in target segments of both the genes by PCR. Further analysis of PCR products of AMA-1 and DBP by RFLP using Pvu-II and Eco R-1 endonucleases respectively, also failed to detect polymorphism in both the genes. The presence of low or no variation within these genes may be due to the functional constraints as both the proteins have important functions in the life cycle of the parasite.

Ever since the discovery of the first case of chloroquine resistance along the Thai-Combodian bor... more Ever since the discovery of the first case of chloroquine resistance along the Thai-Combodian border in the late 1950s, Southeast Asia has played an important role as a focus for the development of drug resistance in Plasmodium falciparum. Although the first case of quinine resistance had been reported much earlier from South America, the onset of chloroquine resistance marked the beginning of a new chapter in the history of malaria in Southeast Asia and by 1973 chloroquine finally had to be replaced by the combination of sulphadoxine and pyrimethamine (SP) as first line drug for the treatment of uncomplicated malaria in Thailand and more than 10 African countries have also switched their first line drug to SP. In 1985, eventually SP was replaced by mefloquine. The rapid development of resistance to this new drug leads to the introduction of artemisinin as a combination drug in the mid-1990s. It is mandatory to mention here that therapeutic regimens for prevention and treatment of chloroquine-resistant P. falciparum are associated with higher costs and side-effects compared to chloroquine. Additionally, some of these alternative treatments are associated with more side-effects, take longer time for cure and are more difficult to comply with than chloroquine. Urgent efforts are needed to identify effective, affordable, alternative antimalarial regimens. Molecular markers for antimalarial resistance have been identified, including pfmdr-1 and pfcrt polymorphisms associated with chloroquine resistance and dhfr and dhps polymorphisms associated with SP resistance. Polymorphisms in pfmdr-1 may also be associated with resistance to chloroquine, mefloquine and artemisinin. Use of such genetic information for the early detection of resistance foci and future monitoring of drug resistant malaria is a potentially useful epidemiological tool, in conjunction with the conventional in vitro and in vivo drug sensitivity assessments. The purpose of this review is to describe the state of knowledge regarding drug resistant malaria and to outline the changing patterns of drug resistance including its determinants, current status in diverse geographical areas, molecular markers and their implications to limit the advent, spread and intensification of drug resistant malaria.

KEY WORD: Echinococcus granulosus has a cosmopolitan distribution with a high prevalence of human... more KEY WORD: Echinococcus granulosus has a cosmopolitan distribution with a high prevalence of human cystic echinococcosis (CE) reported in the southern Mediterranean basin, particularly in parts of North Africa including Libya. Currently, E. granulosus is the only species of the genus Echinococcosis that is found in Libya, and the domestic dog serves as the only known reservoir for the adult tapeworm, and therefore plays a recognized role as the main source of infection causing both public health and veterinary problems. A study of cystic echinococcosis was undertaken in rural and urban areas of northeastern part of Libya to determine the prevalence of hydatid disease among the population. Overall, 32 cases had been treated surgically for Cystic Echinococcosis during 2004 to 2007. The results indicated that the cysts were most frequently found in the liver (66%), followed by the lungs (19%), spleen (3%) and kidney (3%). The prevalence of CE increased significantly with age and females were significantly more affected than males. No differences were found between the two sexes in the location and size of the cysts. Blood samples collected onto filter papers were taken randomly, of which 6% were found to be positive for IgG antibody, females exhibiting a higher prevalence than males for all age groups. These results suggested that the frequency of cystic Echinococcosis in the Tobruk region is significantly high which needs consideration, but a significant difference was not found among the sexes. These results suggest the need for mass screening for hydatidosis in this region of Libya.

Background & objectives: Malaria is a major public health problem in tropical and subtropical cou... more Background & objectives: Malaria is a major public health problem in tropical and subtropical countries. Malaria vaccine is highly desirable as an adjunct to existing malaria control measures. The polymorphism in vaccine candidate antigens might be a hurdle in developing an effective vaccine. Merozoite surface protein-2, apical membrane antigen-1 and circumsporozoite protein of Plasmodium falciparum are vaccine candidate antigens. The aim of this study was to detect extent of genetic polymorphism in potential vaccine candidate antigen genes, i.e. msp-2, ama-1 and csp of P. falciparum isolates prevalent in northern and northwestern parts of India.

Typhoid is a major public health problem in tropical and subtropical countries including India. S... more Typhoid is a major public health problem in tropical and subtropical countries including India. Salmonella typhi, the causative agent of typhoid fever, is a gram-negative, motile, rod shaped, facultative anaerobe. It is solely a human pathogen and there is no animal reservoir. Antibiotic therapy is the mainstay for the treatment of typhoid fever and the complications associated with it. Nowadays, emerging multidrug resistance among Salmonella typhi strains has become a major public health problem. Present research work was carried out for the identification and molecular characterization of Trimethoprim resistant Salmonella enterica serovar typhi strains from individuals suffering with typhoid fever by means of various techniques i.e.; biochemicals, phenotypical and drug resistant gene specific polymerase chain reaction (PCR). A total of 14 blood specimen of infected patients were collected from Solan district of Himachal Pradesh with varying age groups and were processed via broth enrichment methods for primary isolation and identification of typhoid bacilli. Microbiological and biochemical investigations revealed the presence of S. typhi in all 14 specimens. The antibiotic susceptibility assay was carried out for 11 antimicrobial to study the MDR pattern of the identified bacilli. It was observed that 14/14 S. typhi strains were 100% resistance to Trimethoprim, Co-trimoxazole, Sulfanilamide, Penicillin, Ampicillin, Oxacillin, Tetracycline and Erythromycin, and 70-100% susceptible to Levofloxacin, Amikacin and Amoxicillin. The PCR analysis of these MDR strains showed the presence of dhfr a7 (365 bp) gene in only 10/14 isolates. This study confirmed that Trimethoprim resistance in these strains were due to the presence of dhfr a7 gene and also that PCR based diagnosis could be very useful for the rapid detection of drug resistant S. typhi strains. Present study emphasize that Trimethoprim drug is no longer useful for the treatment of typhoid fever as its MIC optimization was very high (750µg/ml). This study may further help the researchers in selecting the appropriate therapeutic approaches targeting Trimethoprim resistant Salmonella typhi strains.

Polymorphism in the block-2 region of merozoite surface protein-1 gene in 69 North Indian Plasmod... more Polymorphism in the block-2 region of merozoite surface protein-1 gene in 69 North Indian Plasmodium falciparum isolates was studied by PCR and RFLP using Dra-1 endonuclease. On the basis of molecular weight of the PCR products, considerable size polymorphism in target gene was seen and 69 isolates were classiWed into Wve allelic types. On RFLP, the isolates in three allelic types were further divided into two sub-allelic types each and thus eight genetic types could be identiWed. Interestingly, all Wve allelic types were identiWed in 47 isolates from uncomplicated (non-cerebral) malaria patients while only two allelic types (Type 2 and 3) were seen amongst 22 isolates from cerebral malaria patients. Furthermore, on RFLP, one subtype (2A) was predominantly seen in cerebral malaria patients and one subtype (3A) was exclusively found in cerebral malaria patients. These observations suggest that a few, comparatively more virulent isolates prevalent in an area may cause severe disease (cerebral malaria) which can be identiWed by molecular techniques like PCR-RFLP.

Indian Journal of Pathology and Microbiology

Malaria is still a major public health problem in many tropical and subtropical countries. Malari... more Malaria is still a major public health problem in many tropical and subtropical countries. Malaria vaccine is highly desirable as an adjunct to existing malaria control measures. The polymorphisms in malaria vaccine candidates antigens might be a hurdle in developing an effective vaccine. The present article reviews the genetic polymorphism in several antigens expressed on the parasite surface, which are targets for immunological responses of the host and are good candidates for vaccine development against P. falciparum. Variable regions of most genes are generally dimorphic probably as a result of intragenic recombinations. Each allele in turn shows polymorphism resulting from point mutations, or other mechanisms. Several antigens like merozoite surface protein-1 and 2 (MSP-1 and MSP-2) and S antigen show high polymorphism while in others like circumsporozoite protein (CSP), apical membrane antigen-1 (AMA-1) and erythrocyte binding antigen-175 (EBA-175) functional constraints limit...

Experimental Parasitology, 2006

Polymorphism in the block-2 region of merozoite surface protein-1 gene in 69 North Indian Plasmod... more Polymorphism in the block-2 region of merozoite surface protein-1 gene in 69 North Indian Plasmodium falciparum isolates was studied by PCR and RFLP using Dra-1 endonuclease. On the basis of molecular weight of the PCR products, considerable size polymorphism in target gene was seen and 69 isolates were classified into five allelic types. On RFLP, the isolates in three allelic types were further divided into two sub-allelic types each and thus eight genetic types could be identified. Interestingly, all five allelic types were identified in 47 isolates from uncomplicated (non-cerebral) malaria patients while only two allelic types (Type 2 and 3) were seen amongst 22 isolates from cerebral malaria patients. Furthermore, on RFLP, one subtype (2A) was predominantly seen in cerebral malaria patients and one subtype (3A) was exclusively found in cerebral malaria patients. These observations suggest that a few, comparatively more virulent isolates prevalent in an area may cause severe disease (cerebral malaria) which can be identified by molecular techniques like PCR-RFLP.

Antibiotic resistance has become a major clinical problem today. Multidrug resistance efflux pump... more Antibiotic resistance has become a major clinical problem today. Multidrug resistance efflux pumps are an important cause of antibiotic resistance in bacteria. Large number of efflux pumps has been characterized so far. These pumps are responsible for the intrinsic resistance of bacteria to antibiotics. Lots of putative EPIs, both chemically and plant derived have been discovered till date against many important bacteria. Initially discovered EPIs have a drawback that they are toxic at the concentrations required for their EPI activity. Some plant extracts also are found to have the potential for containing such compounds based on their very significant synergistic activity with the antibiotics. Many of these EPIs are well studied about their action on the specific pumps and the drug so effluxes. Some of the EPIs are broad spectrum while some narrow-spectrum acting only against one drug/EP family. Research still continues in this direction with an endeavour to hunt a novel, potent, broad-spectrum and promising inhibitor in every way.

Asian Jr. of Microbiol. Biotech. Env. Sc. Vol. 23, No. (2) : 2021 : 163-174, 2021

wjpls, Vol. 7, Issue 4, 153 – 160., 2021

Indian Journal of Pathology and Microbiology

Experimental Parasitology, 2006

Polymorphism in the block-2 region of merozoite surface protein-1 gene in 69 North Indian Plasmod... more Polymorphism in the block-2 region of merozoite surface protein-1 gene in 69 North Indian Plasmodium falciparum isolates was studied by PCR and RFLP using Dra-1 endonuclease. On the basis of molecular weight of the PCR products, considerable size polymorphism in target gene was seen and 69 isolates were classified into five allelic types. On RFLP, the isolates in three allelic types were further divided into two sub-allelic types each and thus eight genetic types could be identified. Interestingly, all five allelic types were identified in 47 isolates from uncomplicated (non-cerebral) malaria patients while only two allelic types (Type 2 and 3) were seen amongst 22 isolates from cerebral malaria patients. Furthermore, on RFLP, one subtype (2A) was predominantly seen in cerebral malaria patients and one subtype (3A) was exclusively found in cerebral malaria patients. These observations suggest that a few, comparatively more virulent isolates prevalent in an area may cause severe disease (cerebral malaria) which can be identified by molecular techniques like PCR-RFLP.