Plasmid mediated multiple antibiotic resistance in Escherichia coli isolated from community acquired infection of urinary tract in Aligarh Hospital

This study was to investigate the current trends of multiple drug resistance in bacteria against antibiotics for the proper empirical treatmen.Clinical isolates were collected from community-acquired infection of urinary tract patients in Aligarh India from March 1999 to August 1999.Antibiotic susceptibility test was performed,using the disc diffusion method followed by plasmid isolation by the method of Kado and Liu.Transfer experiments were performed by the method of Lederberg and Cohen.Clinical study revealed that this infection was more common in young women.Various strains of E.coli isolated during the course of study were found to show multiple antibiotic resistance which was further characterized as plasmid-borne drug resistance.This study shows that E.coli may be one of the important causative agents of urinary tract infection(UTI) in young women.

Prevalence of plasmid mediated bla_(TEM-1) and bla_(CTX-M-15) type extended spectrum beta-lactamases in patients with sepsis

Objective:To characterize the bacterial pathogens in patients having gram negative septicaemia. Further,to evaluate the antimicrobial resistance and underlying molecular mechanisms in these strains.Methods:A total number of 70 cases of gram negative sepsis were included in this prospective,open labeled,observational study.Standard methods for isolation and identification of bacteria were used.Antimicrobial susceptibility and ESBL testing was performed by the standard disc diffusion method.PCR amplification was performed to identify blaCTX-M,blaSHVand blaTEM type ESBLs.Conjugation experiments were performed to show resistant marker transfer. Results:The most prevalent isolates Escherichia coli（E.coli） 58.6%,Klebsiella Spp.32.9%and Pseudomonas 8.6%,were resistant to most of the antimicrobials including cefazolin,ceftriaxone, cefuroxime,ampicillin and co-trimoxazole but sensitive to imipenem and meropenem.ESBL and MBL production was seen 7.3%and 12.2%of E.coli isolates respectively.Three isoaltes were found to have blaCTX-M-15 and two of them also showed blaTEM-1 type enxyme.Whereas, none of them showed blaSHV.Conjugation experiments using J-53 cells confirmed these resistant markers as plasmid mediated.Conclusions:This work highlights the molecular epidemiology of escalating antimicrobial resistance and likely switch over of blaCTX-M-15 type extended spectrum beta-lactamases by blaTEM type ESBLs in India.Further,the antimicrobial resistance by horizontal gene transfer was predominant among Enterobacteraceae in the community setting.

Quick screening and easy detection method of NDM-gene in clinical isolates:A need of the time

The emerging trend of multidrug resistance is becoming a major threat to community acquired and nosocomial infections,worldwide[1].The carbapenems are used as last-source drugs because of increasing resistance against beta-lactam groups of antibiotics due to its excessive use to treat wide range of infections[2].The

Ribozymes:an anti-viral agent

The discovery that RNA can act as an enzyme led Thomas Cech to win the Nobel Prize in Chemistry and led immediately to the next wave of attempts to find an effective RNA-based therapy.The tantalizing idea that RNA enzymes called trans-cleaving ribozymes enables them to act as potential antiviral and powerful tool for functional genomic studies.The efficacy of ribozyme function in a complex intracellular environment is dependent on the intracellular fate of the RNA that is being targeted.Recently,ribozymes have been used successfully to inhibit gene expression in a variety of biological systems in vitro and in vivo.Ribozyme has also been used successfully to combat many cases of viral infection,as clinical trial.Despite it needs to be investigated and explored as far as its structural and functional aspects are concern.In view of the significance of ribozyme in modern medicine,we reviewed the recent literature on general approach to control viral infection.

Swine flu pandemic:a global concern

Recently WHO has again declared Influenza pandemic due to the outbreak of H1N1 which has infected over 254,206 people in 80 countries,with 625 deaths.Our lab has started working on the proteome analysis of H1N1,2009 out break strains.

Multiple drug resistance and bacterial infection

Drug resistance is becoming a great problem in developing countries due to excessive use and misuse of antibiotics. The emergence of new pathogenic strains with resistance developed against most of the antibiotics which may cause,difficult to treat infection.To understand the current scenario in different mode of infection is most important for the clinicians and medical practitioners.This article summarized some common infections and antibiotic resistance pattern found among these pathogens.

Analysis of diabetic foot ulcers in a tertiary care hospital-a clinico-microbiological perspective

Objective:To assess potential risk factors for diabetic foot ulcers infected with multidrug-resistant-organisms(MDROs)and to investigate antibiotic susceptibility patterns and extended-spectrum-β-lactamase(ESBL)-production in bacteria isolated from these ulcers.Methods:Seventy-seven diabetic foot ulcer-patients were studied in a consecutive series.Forty-four study factors were recorded for each patient.Specimens were obtained by scraping the ulcer base or the deep portion of the wound edge with a sterile curette.The soft tissue specimens were quickly sent to the laboratory and processed for microbial pathogens.Gram-negative bacterial isolates were tested for ESBL production by double-disc-diffusion method.The association of study variables with MDRO and non-MDRO infection status of ulcers was tested by Student's t test or Fisher's exact test using SPSS(version 11.5,Chicago).Results:An alarming number of patients were MDRO-positive(72.7%).ESBL-positive strains constituted 19.8% of total isolates.Staphylococcal isolates identified as methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Staphylococcus aureus(VRSA),were 3.7%(n=8)and 0.5%(n=1)respectively.Twenty-two study factors were found to be significantly associated with MDRO infection status of ulcers in the univariate analysis.Multiple logistic regressions proved that MDRO status was the only significant,independent predictor of glycemic control(Odds ratio = 4.22,P<0.01).Conclusion:It is concluded that MDRO infected patients have poor glycemic control.Imipenem and linezolid can be suggested as the drugs of choice in the described setting.

Structural and Functional Analysis of NS1 and NS2 Proteins of H1N1 Subtype

Influenza A virus （H1N1）, a genetic reassortment of endemic strains of human, avian and swine flu, has crossed species barrier to human and apparently acquired the capability of human to human transmission. Some strains of H5N1 subtype are highly virulent because NS 1 protein inhibits antiviral interferon α/β production. Another protein NS2 mediates export of viral ribonucleoprotein from nucleus to the cytoplasm through export signal. In this paper, we have studied structure-function relationships of these proteins of H1N1 subtype and have determined the cause of their pathogenicity. Our results showed that non-conservative mutations slightly stabilized or destabilized structural domains of NS1 or NSI-dsRNA complex, hence slightly increased or decreased the function of NS 1 protein and consequently enhanced or reduced the pathogenicity of the H1N1 virus. NS2 protein of different strains carried non-conservative mutations in different domains, resulting in slight loss of function. These mutations slightly decreased the pathogenicity of the virus. Thus, the results confirm the structure-function relationships of these viral proteins.

Phylogenetic Analysis of the Neuraminidase Gene Reveals that the H5N1 Strains Prevalent in Chickens During 2006 Bird Flu Outbreaks in Two Regions of Maharashtra, India Are Genetically Different

In February 2006, two outbreaks of highly pathogenic avian influenza A virus subtype H5N1 occurred in chickens in two neighboring districts （first in Nandurbar and second in Jalgaon） of Maharashtra, India, in a span of 12 days. In the present study, the neuraminidase （NA） gene of the two Indian H5N1 isolates was taken into consideration to find if the two strains are genetically similar. Phylogenetic analysis of the NA gene showed that the H5N1 strains isolated from the two outbreaks were not originated from the same source. The first Indian isolate （Nandubar/7972/06） was clustered closest to an isolate from chicken in Vietnam in 2004, whereas the second Indian isolate （Jalgaon/8824/06） showed resemblance to strains isolated from swan in Italy and Iran in 2006. Moreover, amino acid sequence analysis showed varying hot spots for substitutions between these two Indian isolates, and three substitutions were found at functional domain sites. Secondary structure changes due to these substitutions were also reported. This study reveals that the H5N1 strains isolated from chickens during 2006 bird flu outbreaks in two neighboring districts of Maharashtra, India are genetically different.

AMDD: Antimicrobial Drug Database

Drug resistance is one of the major concerns for antimicrobial chemotherapy against any particular target. Knowledge of the primary structure of antimicrobial agents and their activities is essential for rational drug design. Thus, we developed a comprehensive database, anti microbial drug database （AMDD）, of known synthetic antibacterial and antifungal compounds that were extracted from the avail- able literature and other chemical databases, e.g., PubChem, PubChem BioAssay and ZINC, etc. The current version of AMDD con- tains -2900 antibacterial and -1200 antifungal compounds. The molecules are annotated with properties such as description, target, format, bioassay, molecular weight, hydrogen bond donor, hydrogen bond acceptor and rotatable bond. The availability of these anti- microbial agents on common platform not only provides useful information but also facilitate the virtual screening process, thus saving time and overcoming difficulties in selecting specific type of inhibitors for the specific targets. AMDD may provide a more effective and efficient way of accessing antimicrobial compounds based on their properties along with the links to their structure and bioassay. All the compounds are freely available at the advanced web-based search interface http：//www.amddatabase.info.