Channappa T. Shivannavar

Vancomycin resistance among methicillin resistant Staphylococcus aureus isolates from intensive care units of tertiary care hospitals in Hyderabad.

Background & objectives: Multidrug resistant methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community acquired infections and is on the rise. The glycopeptide vancomycin has been proposed as the drug of choice for treating such infections. The present study aimed at identifying the vancomycin resistance both phenotypically and genotypically among the MRSA isolates from two tertiary care hospitals in Hyderabad, south India. Methods: MRSA were isolated and identified from different clinical samples collected from ICUs of tertiary care hospitals in Hyderabad using conventional methods. Antibiogram of the isolates and vancomycin MIC were determined following CLSI guidelines. vanA was amplified by PCR using standard primers. Results: All vancomycin resistant S. aureus (VRSA) isolates were MRSA. The VRSA isolates were positive for vanA gene, except one which was negative. All VRSA had a vancomycin MIC in the range of 16-64 mg/l. Interpretation & conclusions: The increase in vancomycin resistance among MRSA and excessive use of antimicrobial agents have worsened the sensitivity. Larger studies need to be done in various geographical regions of the country to better define the epidemiology, mechanism of vancomycin resistance in S. aureus and its clinical implications.

Determination of mycobacterial phylogeny on the basis of immunological relatedness of superoxide dismutases.

Sixteen strains of cultivable mycobacteria were grown in Sautons medium, and Mycobacterium leprae was purified from armadillo liver. Cell extracts were prepared from log-phase growths of each of the cultivable mycobacterial strains. Superoxide dismutase (SOD) enzyme was purified from all cultivable mycobacterial strains included in the study, and antibodies against purified SOD enzyme were raised in rabbits. Immunological distances (ImDs) between these anti-SOD antibodies and SOD antigens were determined by a previously described immunoprecipitation method and by a recently developed enzyme-linked immunosorbent assay (ELISA) technique. The reciprocal ImDs among mycobacterial strains were constant, reproducible and consistent by these two methods. An evolutionary tree was constructed on the basis of estimated ImDs. Except for M. duvalii and M. terrae, slowly and rapidly growing mycobacterial species appeared to be separately grouped by this analysis. Rapid growers clustered into a group which is near that of some slow-growing mycobacteria. M. avium falls almost in the middle of the evolutionary tree and the position of M. leprae was found to be between those of M. avium and M. bovis BCG. Measurement of immunological relatedness of SODs provides an alternative system with which to study the taxonomical relatedness among mycobacteria.

DEGRADATION OF H-ACID BY FREE AND IMMOBILIZED CELLS OF ALCALIGENES LATUS

Alcaligenes latus, isolated from industrial effluent, was able to grow in mineral salts medium with 50 ppm (0.15 mM) of H-acid as a sole source of carbon. Immobilization of Alcaligenes latus in Ca-alginate and polyurethane foam resulted in cells embedded in the matrices. When free cells and immobilized cells were used for biodegradation studies at concentration ranging from 100 ppm (0.3 mM) to 500 ppm (1.15 mM) degradation rate was enhanced with immobilized cells. Cells immobilized in polyurethane foam showed 100% degradation up to 350 ppm (1.05 mM) and 57% degradation at 500 ppm (1.5 mM). Degradation rate of Ca-alginate immobilized cells was less as compared to that of polyurethane foam immobilized cells. With Ca-alginate immobilized cells 100% degradation was recorded up to 200 ppm (0.6 mM) of H-acid and only 33% degradation was recorded at 500 ppm (1.5 mM) of H-acid. Spectral analysis of the products after H-acid utilization showed that the spent medium did not contain any aromatic compounds indicating H-acid degradation by A. latus.

Carriage of capsulated strains of Staphylococcus aureus: a population-based study performed in Gulbarga, South India.

Staphylococcus aureus is a common human pathogen in community- and hospital-acquired infections and its capsule is involved in pathogenesis. We report here the identification of type-5 and type-8 capsular antigens of S. aureus and the prevalence of such strains among volunteers in various age and population groups from different locations in India. S. aureus carriage rates varied between 18 and 50% with the highest values among university students and the lowest in schoolchildren, aged 6-20 years. There was no difference in carriage rates for males vs. females (P=0.415) or in the socioeconomic status of carriers vs. non-carriers or age dependence. Among the carriage isolates 21% were type-5, 52% were type-8 and the remaining 27% were non-typable. Among invasive isolates these percentages were 6, 64 and 30 respectively. This implies that type-5 strains may be less invasive than type-8 strains (P=0.0015).

Biocontrol activity of siderophore producing Bacillus subtilis CTS-G24 against wilt and dry root rot causing fungi in chickpea.

Siderophore producing bacteria as biocontrol agent may play a pivotal role in controlling several fungal pathogens which causes plant diseases. Fusarium oxysporium f. sp. ciceri (FOC) and Macrophomina phaseolina are major phytopathogens amongst the several constraints affecting the productivity of chickpea in India and other countries in Asia. In the present study, indigenous Bacillus subtilis CTS-G24, (Partial 16 S rRNA sequence of Bacillus subtilis is deposited in GenBank with accession number KF322037) was detected positive for siderophore production. Antiphytopathogenic activity of strain CTS-G24 against wilt and dry root rot causing FOC and M. phaseolina respectively was checked. It was revealed that Hydroxamate type of siderophore was produced by CTS-G24 and 64 % of siderophore units was produced in Succinate medium by Bacillus subtilis CTS-G24. Plant Growth Promoting Rhizobacteria (PGPR) are known to influence plant growth by suppressing plant disease and might be applied in agriculture as an alternative to chemical pesticides for improving the quality and yield of crop. Siderophores produced by Bacillus subtilis has got the potentials to

Antibiotic resistance patterns of Staphylococcus aureus: A multi center study from India.

Chemotherapy and emergence of drug resistance strains of Staphylococcus aureus is receiving serious threats, due to the origin and spread of hospital and community acquired MDR strains. The present study reports the prevalence of antibiotic resistance among Staphylococcus aureus isolated from clinical samples from different cities of India. Antibiotic sensitivity was performed by Kirby-Bauer disk diffusion method and minimum inhibitory concentrations were determined for vancomycin and methicillin according to CLSI (2014) guidelines. A total of 212 S. aureus were obtained from different samples such as pus, blood, urine. The antibiogram of these isolates indicated widespread resistance to various groups of antibiotics ranging from a minimum of 10.13% against Phenicols (Chloramphenicol) to a maximum of 97% against Penicillin and 44.8% isolates were MRSA and alarmingly 10.84% were VRSA. Most of the MRSA isolates showed inducible Clindamycin resistance. Widespread prevalence of MDR patterns, increasing incidence of MRSA and VRSA calls for exploration of alternative medicines and new approaches to combat Staphylococcal infections.

Isolation and Characterization of Paracoccus sp. GSM2 Capable of Degrading Textile Azo Dye Reactive Violet 5

A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100 mg/L) within 16 h, while maximally it could decolorize 800 mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0–9.0 and 25–40°C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v). UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2.

Comparison of Capsular Typing of Staphylococcus aureus with Bacteriophage Typing: A Study in Gulbarga, India.

Staphylococcus aureus (S. aureus) is important both as a nosocomial and community acquired pathogen causing various degrees of infections. Typing S. aureus has been a question that is still being addressed. Bacteriophage typing is still used as a golden standard for typing though molecular methods are investigated. In developing countries where neither molecular typing nor the bacteriophage typing methods can be routinely used, the recently developed capsular typing method can be considered as screening method. We compared capsular typing with bacteriophage typing of the strains isolated in Gulbarga, India. We observed that the typeability of capsular typing was significantly higher (96%) among the phage typed strains, and the predominant capsular type in the region was type-8. The data so generated can be used to group S. aureus based on capsules both as a screening prior to bacteriophage typing, and to identify capsular candidate for developing prophylactic and therapeutic alternatives.

Similarity in the isolation rate of Mycobacterium tuberculosis for new and treated cases of tuberculosis in sputum specimens preserved under cetylpyridinium chloride

Sir, Isolation of Mycobacterium tuberculosis from biological samples is essential in drug resistance survey and initiating treatment for cases suspected to developed drug resistance. In cases like treatment after default, failure and relapse, it is important for clinicians to know the status of drug resistance to previous treatment before the initiation of alternative anti-TB regimens. In most of the earlier studies, cetylpyridinium chloride (CPC), was used to preserve and transport sputum specimens for mycobacterial culture and this experience has shown good isolation rate of M. tuberculosis.[1-3] In this study, the effect of CPC was studied to determine the isolation rate of M. tuberculosis from three different categories of tuberculosis attending ten designated microscopic centers (DMC) of Gulbarga district.

Biodegradation of Reactive Red-11 by the Isolate Enterococcus casseliflavus CMGS-1 Strain

Pollutions are the insertion of contaminations, in the natural environments leads to various obstructions, in water pollutants synthetic dye pollution emerging rapidly. In Asia, India may become second major contributor of textile waste water discharging (Verma et al., 2012). The basic structure constituent of dyes are contains n=n bonds, attached to a benzene ring, and various other compounds like SO3H, SO2NH2, NO2 Attached to a aromatic nucleus (Jain et al., 2012). Various physical, chemical methods like reverse osmosis, Fenton’s reagent, chemical flocculation, ion exchange, coagulation, are available but these methods are expensive leads secondary sludge generation and complete degradation cannot be achieved (Jadhav et al., 2012). More than 10000 different kinds of dyes are available in world (Kadam et al., 2011). These dyes are carcinogenic, toxic, and mutagenic in nature. (Shah et al., 2013). The ultimate solution we will get from microorganisms, these are the natural cleaners of the nature. In these direction we selected the potential strain which having the capacity to degrade reactive red-11, confirmed by the FT-IR analysis.