Journal of Microbiology and Biotechnology

1-5

Authors: P Ellaiah

During our continuous search for antibiotic producing actinomycetes, a variant of Streptomyces species was isolated from soils of Andhra Pradesh in India. The morphological, cultural, physiological and biochemical characters were studied, compared to known species and identified as a new variant of Streptomyces noursei and designated as Streptomyces noursei var saccharicus. The antibiotic activity of the strain was tested against both Gram-positive and Gram-negative bacteria as well as fungi and yeasts. INTRODUCTION Since the isolation of actinomycin in 1940 and streptomycin in 1944 by Waksman, the actinomycetes have received tremendous attention of the scientists. Soils, composts and fodders are common sources of actinomycetes. Waksman [1] recognized a few natural substrates as ideal sources for the isolation of actinomycetes and other streptomycetes. The nature of a Streptomyces colony is an important property in characterizing a culture. Krainsky [2] used the structure, size, shape and texture of the colony as one of the major diagnostic criteria. According to Pridham and Lyons [3] and International Subcommittee [4], the best way to handle streptomycete classification nomenclature and identification is through application of the genus-species-subspecies concept. The majority of antibiotic producing actinomycetes found in these species led to growing economic importance of these organisms which resulted in the isolation and description of numerous new species. It is reported that the only genus Streptomyces, the member of Actinomycetales accounts for approximately 93% producing secondary metabolites [5]. The present communication deals with the isolation and characterization of an antibiotic producer from soils.

1-6

Authors: Mustafa Baloch

Nowadays, natural treatment of bacterial diseases using substances which are herbal is of utmost importance. In the present study effects of three antibacterial medicinal plants in south of Iran against the separated Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli from Clinical samples and standard strains was investigated. Hydro-alcoholic extracts of Ziziphora tenuior, Origanum Vulgare and Mentha longifolia were prepared after being dried at shade. In the following the antibacterial activity of the extracts against separated Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli from clinical samples of the Shiraz hospitals and standard samples using disk agar diffusion method was investigated and the drug resistance in the studied samples was conducted using the standard Kirby-Bauer method. The growth of the all studied Staphylococcus aureus and Escherichia coli was stopped by hydro-alcoholic extracts of Mentha longifolia, Ziziphora tenuior and Origanum Vulgare but Pseudomonas aeruginosa showed growth zone of inhibition only against Origanum Vulgare. From statistical viewpoint Origanum Vulgare had also the most antimicrobial effect against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in the all studied samples (P<0.05). Extracts of Mentha longifolia, Origanum Vulgare and Ziziphora tenuior have a potent antibacterial effect against the gram-positive and gram-negative. But on the nosocomial pathogen, Pseudomonas aeruginosa, only Origanum Vulgare has growth inhibitory effect.

1-4

Authors: Barge VU

Chromatography, although primarily a separation technique, is most employed in chemical analysis in biotech plant is SEC which is very powerful technique for protein purification, polymer characterization etc. As the principal advantage of SEC is its gentle non-interaction with the sample, enabling high preservation of biological activity, so SEC has lot of importance in biotech industry. In this review the basic theory, principle & applications of SEC in biotech industry are included.

1-9

Authors: Kandasamy Ulaganathan

A chitinase enzyme, Chi25, was purified from the supernatant of cultured Bacillus subtilis strain BC121 by ammonium sulfate precipitation and chitin affinity chromatography. The purity of the enzyme was confirmed by SDS-PAGE and RP-HPLC analysis and the molecular weight of the enzyme was estimated to be approx. 25 kDa. The enzyme was stable over a pH range of 6–7.5, while the optimal pH for enzyme activity was 6.5. Chi25 was stable over a temperature range of 25–40 °C with 35 °C as the optimal temperature for activity. Bioassay of Chi25 demonstrated the inhibition of spore germination and hyphal extension of important plant pathogenic fungi. Results of the glasshouse trials revealed that the wild-type strain (BC121) reduced fusarium wilt incidence by 80%. Comparative analysis of both the wild-type strain (BC121) and the mutant strain of this bacterium (BC121M) revealed that the antagonism of the BC121 strain against plant pathogenic fungi both in vitro and in vivo is due to the Chi25 enzyme.

1-9

Authors: Mayuri Rani

The importance of host defense against candidiasis and role of cell mediated immunity in host defense has been the subject of many studies. Increased expression of virulence factors in candida isolates from human immunodeficiency virus (HIV) seropositive patients with oropharyngeal candidiasis (OPC) has also been reported. We conducted an experiment to study the difference in T helper type 2 (Th2) and T helper type 1 (Th1) responses and neutrophil respiratory burst responses, of naive peripheral blood mononuclear cells (PBMC’s) and neutrophils respectively, by using Candida isolates from study and control groups as stimulus. Thirty HIV seropositive patients with clinical evidence of OPC and thirty healthy volunteers were studied. IL-10 release was uniformly low at all concentrations of Candida albicans antigen isolated from healthy controls as compared to when C. albicans isolated from HIV seropositive patients was used as antigenic stimulus. Mean IFN-ᵧ concentration was highest when C.albicans, isolated from healthy carriers was used as antigenic stimulus for PBMCs. The observations highlight a significant IL-10 dominance, which may be an indicator of the fine tuning of host immune system towards a chronic progressive disease condition,indicating the pathogenic potential of select Candida strains.

1-5

Authors: R Nalini

The objective of the study is to assess the recent sensitivity pattern of Escherichia coli in Urinary tract infection (UTI).Widespread use of antibiotics has led to the emergence of resistant microorganisms. As the antibiotic sensitivity patterns of the microorganisms are frequently changing, this retrospective analysis was designed to assess the recent antibiotic sensitivity pattern of Escherichia coli (E.coli) in urinary tract infection among the human population. Details of 412 urine culture positive reports for E.coli and their antibiotic sensitivity pattern pertaining to the study period of 12months from June 2012 to May 2013 were collected from Central Microbiology Laboratory of Tirunelveli Medical College and the results were statistically analysed. The antibiotics tested for sensitivity were Amikacin, Gentamycin, Ciprofloxacin, Cotrimoxazole, Nitrofurantoin, Ceftazidime, Ceftriaxone and Cefotaxime. The sensitivity pattern of E.coli to antibiotics in UTI were Nitrofurantoin (85.19%), Amikacin (66.50%), Co-trimoxazole(31.31%), Gentamycin (26.90%), Ceftazidime (26.69%) ,Ciprofloxacin (22.57%), Cefotaxime (22.30%), Ceftriaxone (17.47%). The study highlighted the re-emergence of E. coli sensitive to Nitrofurantoin and marked resistance of E.coli to Aminoglycoside and third generation Cephalosporins.

1-6

Authors: Y Gayatri

A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus species and Enterococcus species. Beneficial effects of food, milk product and medicinal capsules with live microbes (probiotics) on human health are being increasingly promoted by professionals. These benefits include antimicrobial, anti-mutagenic effects, anti-carcinogenic properties, improvement in lactose metabolism, reduction in serum cholesterol and immune system stimulation. Several studies in recent years have shown the benefits deriving from the ingestion of probiotics. The objective of this study was to screen ten potential probiotic organisms from total of 10 different food samples, milks products, and medicinal capsules were collected. The organisms identified on the basis of phenotypic characters and biochemical properties were Enterococci durans, Lactobacillus rhamnous, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus lactis. It was observed that similar types of probiotic organisms were isolated from food items, milk products and medicinal capsules.

1-4

Authors: Ritika Goyal

The presence of one STI increases the risk of having concomitant and co-transmission of other STI. An evolving trend of Candida infections in STI patients, showing a transition from harmless colonizers to unrelenting pathogens, is a fine line attributable to extensive repertoire of virulence determinants. The present study was carried out to identify the genital Candida flora prevalent in patients attending sexually transmitted disease (STD) Clinic and to determine the haemolysin and phospholipase activity amongst these isolates. Further, correlation of species of infecting/ prevalent Candida with the co-existing STI was done. A total of 75 consecutive male and female patients, presenting with one or more of the complaints as enunciated by World Health Organization (WHO) in the Syndromic Approach for the diagnosis of STIs, were included in the study. Candida was isolated in significantly higher numbers from patients presenting with discharge (47%) followed by balanitis (30%), and genital ulcer (23%). C. albicans (73%) was predominant isolate in various STIs. Hemolysin index and phospholipase activity of C. albicans was found significantly higher enhancing their pathogenic potential. The study suggests the role of genital inflammation by Candida as a significant cofactor in STI acquisition and existence of genital Candida as colonizer or pathogen. The study provides a rational basis for empirical therapy in STI patients.

1-4

Authors: Sapna Rai

Clinical fungi were isolated from the blood samples of immunocompromised patients from Subhash Chandra Medical College Jabalpur in SDA with chloramphenicol @ 30μg/ml.the common isolates were Candida albicans, Aspergillus fumigatus, A. glaucus, A.terreus, A. niger, A. flavus, Penicillium sps. and Curvularia sps. The isolates were then subjected to in vitro susceptibility testing against different antifungals viz Amphotericin B, Ketocaonazole, itraconazole, clotrimazoleand fluconazole and also against natural herbs like neem, tulsi, garlic ginger, aloevra, turmeric etc by DDM method. Ketocaonazole was found to be highly effective amongst all antifungals and garlic was most effective amongst all natural antifungals.

1-8

Authors: Tapan Majumdar

β-lactam antibiotics are the most widely used chemotherapeutic agents. Commonest cause of resistance towards β-lactam antibiotics is the production of β-lactamases. Isolation, identification and antibiogram of the members of Enterobacteriaceae and Pseudomonaceae from the clinical samples. Detection of Extended spectrum β-Lactamase and AmpC β-Lactamase producing Enterobacteriaceae and Pseudomonadaceae by phenotypic method. Culture isolation, identification and antibiogram of the isolates were performed followed by detection of Extended spectrum β-Lactamase by Double Disc Synergy Test and Phenotypic disc confirmatory test, whereas AmpC β-Lactamase was detected by Disc Antagonism Test and Double Disc Synergy Test. Out of 200 isolates, 54% are Extended spectrum β-Lactamase producers, 48.5% are AmpC β-Lactamase producers. Predominant ESBLs producers are Klebsiella pneumonia and Escherichia coli. In case of Pseudomonadaceae, 88% of Pseudomonas aeruginosa and 100% of Pseudomonas fluorescens has shown presence of AmpC β-Lactamase and 66% of Providencia alcalifaciens produced combined Extended spectrum β-Lactamase and AmpC β-Lactamase. Out of the 97AmpC β-Lactamase producers, 45.4% and 54.6% are inducible and plasmid mediated AmpC β-Lactamase producers respectively. This study shows high rate of circulating extended spectrum β-Lactamase and AmpC β-Lactamase producers in our hospital setup. Development of antimicrobial stewardship program based on the local epidemiological data and national guidelines is the need of the hour.

1-9

Authors: Femi Kayode Agboola

Textile dye waste-water presents an enormous task in its disposal. This present study aims to identify fungus capable of producing extracellular laccases that under optimized conditions can decolourize textile dyes. Auerobasidium pullulans and Cladosporium werneckii isolated from soil and decayed wood respectively were identified as laccase producing fungi. Physiological conditions for maximal laccase production were investigated. The fungal biomass was determined to correlate laccase production and its growth. The optimized culture broth was used in decolourization of several textile dyes. A. pullulans had maximum laccase activity of 19.18 U/ml on the ninth day of incubation; it utilized glucose, maximum laccase activity was observed at 37 ˚C and pH 6.0 whereas C. werneckii preferred galactose, produced maximum activity of 1.53 U/ml on the twelfth day, had optimum activity at 30 ˚C and pH 5.0. Both fungal isolates preferred tryptophan as nitrogen source and utilized inoculum size of 24 mm and 0.3 mM of CuSO4 for optimal laccase production. A. pullulans laccase is constitutive whereas C. werneckii is inducible. The increase or decrease in laccase activity is in direct proportion to the rate of fungal growth. Optimized culture broth from A. pullulans and C. werneckii had 1.25 and 2.03 fold increase in laccase activity respectively and they were both able to decolourize malachite green specifically i. e 73% and 35% and had least decolourizing abilities on methylene blue in the absence of inducers and after three hours of incubation. The ability of these newly isolated fungal strains to produce laccase extracellularlly and also decolourize dyes would serve as a way to eliminate industrial textile waste water.

1-14

Authors: Madhavan HN

Chloramphenicol has remained as a potent broad spectrum antibiotic over decades and due to its side effects its usage has been limited. In an era of increasing resistance to many antibacterial agents, chloramphenicol might have a role in the treatment of intra abdominal infections and respiratory tract infections caused by multi drug-resistant pathogens. This review article focuses on the spectrum of activity of chloramphenicol, mechanism of action , side effects , its parentral and oral use, its resistance mechanisms, toxicity elucidated by enteric pathogens against it and also on the possibility of its therapeutic use in treatment of multi - drug resistant bacterial infections.

1-4

Authors: Murugesan Subban

Bacterium exhibiting extra-cellular catalase activity was isolated from lime stone soil. Catalase is an essential component of the cell to cope up with oxidative stress. This study deals with simple detection method by plate assay for catalase activity from bacterium Acinetobacter calcoaceticus AV-6. Rapid assay method involves plating the supernatant on the substrate bound agar with the dye. This assay gave result within 60 s, producing a zone around the well. This enzyme was extracted from stationary phase at 36 h. The molecular weight of the protein was determined to be approximately 60 kDa. Sequencing studies were carried out and the strain Acinetobacter calcoaceticus AV6 was partially sequenced. The results imply the significance of this detection method in industries.

1-6

Authors: Eziashi E I

The fungal and bacterial populations in soil waste dumping site (WDS) and oil palm ecosystem (OPE) cultivated with oil palm seedlings have been studied. The month of April had the highest occurrence with 20.1 x 105 cfu/g from WDS. This was followed by May with 12.8 x 105 cfu/g (WDS), July 10.1 x 105 cfu/g (OPE) and August showed the lowest occurrence with 7.1 x105 cfu/g (OPE). The mean bacterial counts for the month of July recorded the highest occurrence with 8.42 x 103 from OPE. This was followed by May with 5.98 x 103 cfu/g (WDS), April 4.45 x 103 cfu/g (WDS) and August showed the lowest with 1.60 x 103 (OPE). The biochemical tests revealed the occurrence of eleven isolates. The Bacillus subtilis was the most occurred while Flavobacteria devorans was the least occurred. The frequency of occurrence of fungi isolated revealed that Penicillium expansium had the highest occurrence with 11.7%. The least occurrence was Trichoderma polysporum with 1.1%. The high counts of fungi and bacteria obtained in soil from WDS were an indication that the soil was influenced by the degrading matters at the sites. The soil from waste dumping sites best supported high fungal and bacterial populations while soil from oil palm ecosystem less supported the populations.

1-12

Authors: Shubha Gopal

Listeria is a ubiquitous organism and can be isolated from a variety of sources such as raw foods, soil, stream water, silage, sewage, plants. It is also been found in uncooked meats, fish, uncooked vegetables, unpasteurized milks, their products, processed foods and food processing environments from different parts of the world. Various methods are used to sanitize the food processing environments and to control the organism from the food and the food processing environments. Proper surveillance, rapid detection of Listeria is important to ensure the safety of food products. The article reviews major Listeria incidences in food and food related environments from a global perspective.