Ferment Maltose Research Articles

Isolation, identification and antibiogram profiles of enterovirulent Escherichia coli from diarrhoeic goat in some selected areas of Rangpur district of Bangladesh

Enterovirulent Escherichia coli remain as an important etiological agent of goat diarrhoea in Bangladesh. The present study was designed with a view to isolate and identifies E. coli from field cases. For this purpose, a total of 135 faecal samples (85 from diarrhoeic and 50 from apparently healthy goat) were collected during the period from January 2012 to July 2012 from different areas in Rangpur District. It was found that the prevalence of E. coli was higher (18.82 %) in diarrhoeic goats while it was lower (14.00 %) in non diarrhoeic goats. Age wise distribution of E. coli isolates were 26.42% in day old to 1 year, 10.53% in 1-2 years and 11.36% in above 2 years age of goat respectively. All the isolates of E. coli revealed greenish black colony with metallic sheen in Eosine methylene blue agar, bright pink color smooth transparent colony in MacConkey agar and slight pinkish smooth colony in Salmonella-Shigella agar. Gram stain and hanging drop techniques were performed with the cultured bacteria. Biochemical properties of the isolates were studied, and antibiotic sensitivity test was done by agar disk diffusion method. In Gram stain, the organisms revealed Gram negative, small rod shaped, occurs singly or paired. Biochemically, all of the isolates showed fermentation of dextrose, sucrose and maltose with the production of acid and gas, negative result to Voges-Proskauer test, positive result to Methylred test and differential result to Indol test. All the isolates of E. coli were highly sensitive to ciprofloxacin and gentamicin while moderately sensitive to colistin, livofloxacin and azithromycin and less sensitive to ceftraexon and tetracyclin and resistant to amoxycillin, ampicillin, erythromycin, and neomycin. Therefore, ciprofloxacin and gentamicin may be the antibiotics of first choice, and colistin, livofloxacin and azithromycin may be the second choice among the test antibiotics for the treatment of illness caused by these bacteria.Asian J. Med. Biol. Res. March 2018, 4(1): 36-43

Simple and economical method for identification and speciation of Staphylococcus epidermidis and other coagulase negative Staphylococci and its validation by molecular methods

Coagulase-negative staphylococci (CoNS) have been increasingly recognized as a clinically important group of species that can cause several opportunistic nosocomial infections. There are at least 47 known species of Staphylococci and to differentiate all these species >40 biochemical tests need to be performed. The present study was able to refine the CoNS identification process by using only five tests to identify S. epidermidis from the rest and used six other tests to identify eleven other clinically significant CoNS species. A total of 242 CoNS isolates were collected from tertiary care hospitals and included in the study. The five-biochemical test scheme devised based on mathematical probability derived from a computer algorithm included fermentation of mannitol, maltose, mannose, trehalose and novobiocin susceptibility to differentiate S. epidermidis from other CoNS species. The remaining CoNS isolates other than S. epidermidis were further characterized with the help of six additional tests, which identified another eleven species. Species-specific PCR and 16SrDNA sequencing were used to confirm and validate the identification scheme. Species-specific PCR and 16SrDNA sequencing showed 100% agreement with non-divergent phenotypic test results, indicating that the five selected assays are highly specific for identifying S. epidermidis. In conclusion, this study used only 11 tests to identify most of the clinically significant CoNS that can reduce cost and time. This scheme is easy to perform in any laboratory with basic resources, the results of this study were validated using more accurate molecular methods such as PCR and 16S rDNA typing to confirm the utility of the proposed scheme.

Caseous Lymphadenitis Caused by Corynebacterium pseudotuberculosis in Alpine Chamois (Rupicapra r. rupicapra): a Review of 98 Cases

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis (CLA) in domestic and wild ruminants. Here we describe CLA in alpine chamois (Rupicapra r. rupicapra) based on a series of 98 cases of C. pseudotuberculosis infection confirmed by bacteriology and gene sequence analysis. The population included 53 males and 45 females distributed within three age groups: up to 18 months (n=14), 18 months to 4 years (n=11) and over 4 years (n=73). Four different gross lesion distribution patterns, observed individually or variably combined in the same animal, were defined: (1) cutaneous/external (i.e. subcutaneous lymph nodes with or without muscle involvement, n=34); (2) abdominal visceral (i.e. only abdominal organs involved: liver and/or spleen and/or kidney and/or lymph nodes, n=35); (3) thoracic visceral (i.e. only thoracic organs involved: lung and/or heart and/or lymph nodes, n=26); and (4) generalized visceral (i.e. abdominal and thoracic organs involved, n=26). In six particularly severe cases, mammary gland, testis, vertebral bone and the central nervous system were also affected. Macroscopically, most abscesses were characterized by fluid pus, confirmed by microscopy that showed the absence of distinct concentric layers and coagulative necrosis, which are typically seen in sheep and goats raised in areas where the infection is endemic. In three cases amyloid deposits were observed in the liver and kidney. The C. pseudotuberculosis strains isolated were highly homologous to the reference strain ATCC 19410, except for some variability in their ability to ferment maltose and mannitol. Based on the production of nitrate reductase, 95 strains were attributed to the ovis biovar (nitrate reduction negative) and three to the equi biovar (nitrate reduction positive). All strains were sensitive to antibiotics, except to ampicillin (62.3% resistant strains) and gentamicin (83.7% resistant strains). Using an indirect enzyme-linked immunosorbent assay designed for CLA in sheep and goats, seven (58.3%) of 12 serum samples tested positive for antibodies.

Cachaça yeast strains: alternative starters to produce beer and bioethanol.

This work was performed to verify the potential of yeast strains isolated from cachaça distilleries for two specific biotechnological applications: beer and bioethanol production. In the beer production, the strains were tested for characteristics required in brewery practices, such as: capacity to ferment maltose and maltotriose, ability to grow at lowest temperatures, low H2S production, and flocculation profile. Among the strains tested, two of them showed appropriate characteristics to produce two different beer styles: lager and ale. Moreover, both strains were tested for cachaça production and the results confirmed the capacity of these strains to improve the quality of cachaça. In the bioethanol production, the fermentation process was performed similarly to that used by bioethanol industries: recycling of yeast biomass in the fermentative process with sulfuric acid washings (pH 2.0). The production of ethanol, glycerol, organic acids, dry cell weight, carbohydrate consumption, and cellular viability were analyzed. One strain presented fermentative parameters similar to PE2, industrial/commercial strain, with equivalent ethanol yields and cellular viability during all fermentative cycles. This work demonstrates that cachaça distilleries seem to be an interesting environment to select new yeast strains to be used in biotechnology applications as beer and bioethanol production.

New Lager Brewery Strains Obtained by Crossing Techniques Using Cachaça (Brazilian Spirit) Yeasts.

The development of hybrids has been an effective approach to generate novel yeast strains with optimal technological profile for use in beer production. This study describes the generation of a new yeast strain for lager beer production by direct mating between two Saccharomyces cerevisiae strains isolated from cachaça distilleries: one that was strongly flocculent, and the other with higher production of acetate esters. The first step in this procedure was to analyze the sporulation ability and reproductive cycle of strains belonging to a specific collection of yeasts isolated from cachaça fermentation vats. Most strains showed high rates of sporulation, spore viability, and homothallic behavior. In order to obtain new yeast strains with desirable properties useful for lager beer production, we compare haploid-to-haploid and diploid-to-diploid mating procedures. Moreover, an assessment of parental phenotype traits showed that the segregant diploid C2-1d generated from a diploid-to-diploid mating experiment showed good fermentation performance at low temperature, high flocculation capacity, and desirable production of acetate esters that was significantly better than that of one type lager strain. Therefore, strain C2-1d might be an important candidate for the production of lager beer, with distinct fruit traces and originating using a non-genetically modified organism (GMO) approach.IMPORTANCE Recent work has suggested the utilization of hybridization techniques for the generation of novel non-genetically modified brewing yeast strains with combined properties not commonly found in a unique yeast strain. We have observed remarkable traits, especially low temperature tolerance, maltotriose utilization, flocculation ability, and production of volatile aroma compounds, among a collection of Saccharomyces cerevisiae strains isolated from cachaça distilleries, which allow their utilization in the production of beer. The significance of our research is in the use of breeding/hybridization techniques to generate yeast strains that would be appropriate for producing new lager beers by exploring the capacity of cachaça yeast strains to flocculate and to ferment maltose at low temperature, with the concomitant production of flavoring compounds.

Study on the Prevalence and Distribution of Staphylococcus aureus in Raw Cow Milk Originated from Alage Atvet College Dairy Farm, Ethiopia

This investigation was carried out from October 2011-June 2012 to determine the prevalence of Staphylococcus in milk and rate of contamination at farm and milk distribution tank in Alage Agricultural Technical Vocational Educational Training College. Milk samples (row) were cultured on sheep blood agar and incubated. The plates were examined for gross colony morphology, pigmentation and haemolytic characteristics at 24-48 h then presumptive colonies of Staphylococcus aureus was selected and sub cultured on nutrient agar and incubated. Then, bacteria were identified according to its Gram reaction, morphology and the catalase test, tube coagulase test (4 h), haemolysis, pigment production (golden yellow), mannitol and maltose fermentation were used. A total of 170 milk sample of cow were examined for bacteriological status of S. aureus, an overall 28.2% prevalence of Staphylococcus was found. From this, 21.2% was directly from the farm and 35.3% were from milk distributing site to consumers. The total prevalence of Staphylococcus varied among the sample taking site. The prevalence of S. aureus from distributing raw milk site (35.3%) was significantly higher than the prevalence of S. aureus from samples taken directly from the farm (21.2%). From this the study it is considered that Staphylococcosis a potential hazard for the public and contamination rate is high in distribution site which needs improvement of the hygienic status of the personnel’s at distribution site.

Maltose and maltotriose utilisation by groupI strains of the hybrid lager yeast Saccharomyces pastorianus.

Brewer's wort is a challenging environment for yeast as it contains predominantly α-glucoside sugars. There exist two subgroups of the lager yeast Saccharomyces pastorianus which differ in sugar utilisation. We performed wort fermentations and compared representative strains from both groups with respect to their ability to transport and ferment maltose and maltotriose. Additionally, we mapped the transporters MALx1, AGT1, MPHx and MTT1 by Southern blotting. Contrary to previous observations, group I comprises a diverse set of strains, with varying ability to transport and ferment maltotriose. Of the eight group I strains, three efficiently utilised maltotriose, a property enabled by the presence of transmembrane transporters SeAGT1 and MTT1. A58, a variant of the group I type strain (CBS1513) performed particularly well, taking up maltotriose at a higher rate than maltose and retaining significant transport activity at temperatures as low as 0°C. Analysis of transporter distribution in this strain revealed an increased copy number of the MTT1 gene, which encodes the only permease known with higher affinity for maltotriose than maltose and low temperature dependence for transport. We propose that much of the variation in lager yeast fermentation behaviour is determined by the presence or absence of specific transmembrane transporters.

Genomic and physiological analysis reveals versatile metabolic capacity of deep-sea Photobacterium phosphoreum ANT-2200.

Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

Isolation, Identification and Antibiogram ofStaphylococcus aureusIsolated from Bovine Mastitis

In the present study, out of 255 milk samples (185 from subclinical and 70 from clinical cases) screened for Staphylococcus aureus, 53 isolates were obtained giving an overall incidence of 20.78%. The incidence of S. aureus from subclinical mastitis was 8.11% (15/185) and from clinical mastitis was 54.29% (38/70). Species-wise incidence was 30.77% (16/52) in buffaloes and 18.23% (37/203) in cows. All 53 isolates were identified on the basis of colony characters on nutrient agar, staining and biochemical characters namely catalase production, oxidise test, maltose fermentation test and ohosphatase test. Out of 53 isolates, 49 (92.45%) isolates showed coagulase production in tube coagulase test. Number of isolates showing alpha, beta, gamma and alpha-beta haemolysin production were 18 (33.96%), 26 (49.06%), 4 (7.55%) and 5 (9.43%) on sheep blood agar, respectively. All the 53 S. aureus isolates were confirmed genotypically by 23S rRNA ribotyping in which a species-specific amplicon of 1, 250 bp was obtained. Antibiotic sensitivity patterns of all these 53 S. aureus isolates revealed that the isolates were most sensitive to gentamicin (94.34%), whereas penicillin (94.34%) and ampicillin (86.79%) were highly resistant to S. aureus.

Recent Advances in Diagnosis of Flavobacteriosis Among Some Freshwater Fishes

Columnaris disease caused by Flavobacterium columnare exists worldwide and affects a wide variety of fishes. This study aimed to investigate the isolation and characterization of Flavobacterium columnare from naturally infected fishes (Oreochromis niloticus and Clarias gariepinus) in Ismailia, using conventional biochemical methods and molecular techniques. Bacteriological examination revealed presence of 162 suspected Cytophaga isolates of which only 102 isolates were characterized as F. columnare strains according to colony character on Cytophaga agar which appeared yellow or whitish yellow in color, flat irregular with stiletto edge, clear swarming and rhizoid characters. Biochemical characterizations demonstrated that all isolates tested uniformly positive for catalase, gelatin liquefaction, absorption of Congo Red and flexirubin pigment, but they were negative for indol, Methyl red, Vogus Proskauer, and lactose, glucose, saccharose, manitol, arabinose and maltose fermentation. All isolates produced unique and clear PCR bands of the expected size (675 base pair). Consequently, PCR confirmed the positive results of the biochemical reactions of suspected isolated strain and concluded that it is of F.columnare.

Effects of SNF1 on Maltose Metabolism and Leavening Ability of Baker's Yeast in Lean Dough.

Maltose metabolism of baker's yeast (Saccharomyces cerevisiae) in lean dough is negatively influenced by glucose repression, thereby delaying the dough fermentation. To improve maltose metabolism and leavening ability, it is necessary to alleviate glucose repression. The Snf1 protein kinase is well known to be essential for the response to glucose repression and required for transcription of glucose-repressed genes including the maltose-utilization genes (MAL). In this study, the SNF1 overexpression and deletion industrial baker's yeast strains were constructed and characterized in terms of maltose utilization, growth and fermentation characteristics, mRNA levels of MAL genes (MAL62 encoding the maltase and MAL61 encoding the maltose permease) and maltase and maltose permease activities. Our results suggest that overexpression of SNF1 was effective to glucose derepression for enhancing MAL expression levels and enzymes (maltase and maltose permease) activities. These enhancements could result in an 18% increase in maltose metabolism of industrial baker's yeast in LSMLD medium (the low sugar model liquid dough fermentation medium) containing glucose and maltose and a 15% increase in leavening ability in lean dough. These findings provide a valuable insight of breeding industrial baker's yeast for rapid fermentation.

Chromosomal Copy Number Variation in Saccharomyces pastorianus Is Evidence for Extensive Genome Dynamics in Industrial Lager Brewing Strains.

Lager brewing strains of Saccharomyces pastorianus are natural interspecific hybrids originating from the spontaneous hybridization of Saccharomyces cerevisiae and Saccharomyces eubayanus. Over the past 500 years, S. pastorianus has been domesticated to become one of the most important industrial microorganisms. Production of lager-type beers requires a set of essential phenotypes, including the ability to ferment maltose and maltotriose at low temperature, the production of flavors and aromas, and the ability to flocculate. Understanding of the molecular basis of complex brewing-related phenotypic traits is a prerequisite for rational strain improvement. While genome sequences have been reported, the variability and dynamics of S. pastorianus genomes have not been investigated in detail. Here, using deep sequencing and chromosome copy number analysis, we showed that S. pastorianus strain CBS1483 exhibited extensive aneuploidy. This was confirmed by quantitative PCR and by flow cytometry. As a direct consequence of this aneuploidy, a massive number of sequence variants was identified, leading to at least 1,800 additional protein variants in S. pastorianus CBS1483. Analysis of eight additional S. pastorianus strains revealed that the previously defined group I strains showed comparable karyotypes, while group II strains showed large interstrain karyotypic variability. Comparison of three strains with nearly identical genome sequences revealed substantial chromosome copy number variation, which may contribute to strain-specific phenotypic traits. The observed variability of lager yeast genomes demonstrates that systematic linking of genotype to phenotype requires a three-dimensional genome analysis encompassing physical chromosomal structures, the copy number of individual chromosomes or chromosomal regions, and the allelic variation of copies of individual genes.

Effects of MAL61 and MAL62 overexpression on maltose fermentation of baker’s yeast in lean dough

The predominant fermentable sugar in lean dough is maltose. To improve the leavening ability of baker's yeast in lean dough, maltose metabolism should be improved. Maltase (alpha-glucosidase, encoded by MAL62) and maltose permease (encoded by MAL61) are the major factors involved in maltose metabolism. The major rate-limiting factor in maltose metabolism and leavening ability of baker's yeast remains unclear. In this work, MAL61 and/or MAL62 overexpression strains were constructed to investigate the decisive factor for maltose metabolism of industrial baker's yeast in lean dough. Our results show that elevated maltose permease activity by MAL61 overexpression yielded less improvement in maltose fermentation compared to elevated maltase activity by MAL62 overexpression. Significant increase in maltase activity by MAL62 overexpression could result in a 44% increase in leavening ability of industrial baker's yeast in lean dough and a 39% increase in maltose metabolism in a medium containing glucose and maltose. Thus, maltase was the rate-limiting factor in maltose fermentation of industrial baker's yeast in lean dough. This study lays a foundation for breeding of industrial baker's yeast for quick dough leavening.

Rouxiella chamberiensis gen. nov., sp. nov., a member of the family Enterobacteriaceae isolated from parenteral nutrition bags.

Parenteral nutrition bags for newborns were found contaminated by a previously undescribed member of the family Enterobacteriaceae. The six isolates studied by rrs gene (encoding 16S rRNA) sequence analysis and multi-locus sequence analysis (MLSA) formed a discrete branch close to the genera Ewingella, Rahnella, Yersinia,Hafnia and Serratia. Phenotypically, the new taxon was distinct from these five genera. The new taxon gave positive results in Voges-Proskauer, Simmons citrate and o-nitrophenyl-β-galactoside hydrolysis tests; fermented d-glucose, d-mannitol, l-rhamnose, melibiose, l-arabinose and d-xylose; hydrolysed aesculin; and did not ferment maltose, trehalose, raffinose, d-sorbitol, sucrose or cellobiose. Tests for motility, gas production, urease, gelatinase and nitrate reduction were also negative. All isolates failed to grow at 37 °C. The DNA G+C content of strain 130333T was 53 mol%. On the basis of data obtained in this study, the six isolates represent a novel species of a new genus in the family Enterobacteriaceae, named Rouxiella chamberiensis gen. nov., sp. nov. The type strain of the type species is 130333T ( = CIP 110714T = DSM 28324T).

English

Variability exists in raw materials and processing methods used to produce household traditional opaque beers in Zimbabwe, resulting in beers of variable quality, depending on fermenting micro-organisms involved. Yeasts are important in determining the alcohol content, nutrition and organoleptic properties of the beers. This study aimed at determining the diversity and characteristics of the predominant yeasts isolated from a variety of beers collected from rural households in different geographical localizations. Predominant yeasts from 13 beer samples were characterized using morphological, biochemical and physiological tests. A total of 14 morphologically different yeasts were isolated. Yeast counts in the beer samples ranged from 7.87 to 9.56 log colony forming units/ml. From the 14 yeast isolates, a total of 11 yeasts were identified to species level. Saccharomyces cerevisiae was the predominant species identified in the beers. Other yeast species identified in the beers were Issatchenkia occidentalis, Kluyveromyces marxianus, Candida glabrata and Sporobolomyces holsaticus. Two yeast isolates were identified as belonging to the genus Rhodotorula. Ten of the isolates were able to ferment at least one of the fermentation substrates D-glucose, D-galactose, maltose, sucrose and raffinose, while three isolates were incapable of fermenting any of the fermentation substrates used. None of the isolates were able to ferment lactose. Five of the S. cerevisiae isolates were able to grow at 40°C while K. marxianus was the only isolate capable of growing at 45°C. Key words: Yeasts, characterisation, traditional opaque beer.

Promotion of maltose fermentation at extremely low temperatures using a cryotolerant Saccharomyces cerevisiae strain immobilized on porous cellulosic material

Advantages in maltose fermentation at extremely low temperatures (5–10°C) using an alcohol resistant and cryotolerant yeast strain (Saccharomyces cerevisiae AXAZ-1) immobilized on porous cellulosic material (or tubular cellulose, TC), produced by delignification of wood sawdust, are reported. Pure maltose and glucose media (80, 100 and 140g/l) were examined as model substrates to evaluate the potential effect of TC on the rate of fermentation of maltose containing substrates. The use of TC sharply accelerated the rate of maltose fermentation compared to free cells (FC) in suspension. Fermentation at 5°C by immobilized cells was complete, while FC were unable to ferment maltose at this temperature, in contrast to glucose, which was completely fermented. From the results of maltose and glucose fermentations at 5 and 10°C, it was concluded that the effect of TC was higher at lower fermentation temperature and that its promotional effect on fermentation rate had to be at the step of maltose uptake. Specifically, it is suggested that the presence of TC increased maltose uptake rate by the immobilized cells due to attraction by hydrogen bonding on the TC surface and continuous pumping of maltose towards the cells. Calculation of the activation energy of maltose fermentations at 5, 10 and 15°C showed that it was reduced by an average 42% when cells immobilized on TC were used.

Acetyltransferase SAS2 and sirtuin SIR2, respectively, control flocculation and biofilm formation in wine yeast.

Cell-to-cell and cell-to-environment interactions of microorganisms are of substantial relevance for their biotechnological use. In the yeast Saccharomyces cerevisiae, flocculation can be an advantage to clarify final liquid products after fermentation, and biofilm formation may be relevant for the encapsulation of strains of interest. The adhesion properties of wine yeast strains can be modified by the genetic manipulation of transcriptional regulatory proteins, such as histone deacetylases, and acetylases. Sirtuin SIR2 is essential for the formation of mat structures, a kind of biofilm that requires the expression of cell-wall protein FLO11 as its deletion reduces FLO11 expression, and adhesion of cells to themselves and to agar in a commercial wine strain. Deletion of acetyltransferase GCN5 leads to a similar phenotype. A naturally flocculant wine yeast strain called P2 was characterized. Its flocculation happens only during grape juice fermentation and is due to the presence of a highly transcribed version of flocculin FLO5, linked to the presence of a δ sequence in the promoter. Deletion of acetyltransferase SAS2 enhances this phenotype and maltose fermentation even more. Therefore, the manipulation of acetylation/deacetylation machinery members is a valid way to alter the interaction of industrial yeast to their environment.

Occurrence of Pasteurellosis and Newcastle Disease in indigenous chickens in Sirajgonj district

A study was carried out on indigenous layer chickens to know occurrence of Avian Pasteurellosis (AP) and Newcastle disease (ND) in Sirajgonj during the period from January/2012 to December/2013. The clinical signs showed before death was recorded by taking history and the birds were subjected to post mortem examination. In addition to the clinical and necropsy findings, ND was detected by Anigen® rapid antigen detection kit. The AP was confirmed by isolation and identification of Pasteurella (P.) multocida from liver, spleen and heart samples. The P. multocida was found to grow on nutrient broth, nutrient agar, blood agar and Eosin Methylene Blue agar where it produced whitish, opaque, round, flat, translucent colonies. It produced turbidity on nutrient broth. The organism was not found to grow on MacConkey agar media and did not cause hemolysis on blood agar media. The impression smear of liver and heart blood were stained by Gram’s staining, Leishman staining and Methylene blue staining techniques to detect P. multocida. P. multocida organism was also found to fermnt dextrose, lactose and mannitol with the production of only acid but did not ferment maltose and lactose. P. mutocida was found non-motile, indole positive and urease negative. On triple sugar iron test it produced H2S and fermented only glucose. It was found negative to both methyl red test and Voges Proskauer test. Out of 360 birds tested 59.72% (215) was AP positive and 40.28% was ND positive. Age, Sex, season and mortality due to other diseases were not considered.DOI: http://dx.doi.org/10.3329/bjvm.v11i2.19123 Bangl. J. Vet. Med. (2013). 11 (2): 97-105

Virulence, Speciation and Antibiotic Susceptibility of Ocular Coagualase Negative Staphylococci (CoNS).

Coagulase negative Staphylococci (CoNS) are common inhabitants of human skin and mucous membranes. With the emergence of these organisms as prominent pathogens in patients with ocular infections, investigation has intensified in an effort to identify important virulence factors and to inform new approaches to treatment and prevention. To isolate CoNS from ocular specimens; to study the possible virulence factors; speciation of coagulase negative staphylococci (CoNS) which were isolated from ocular complications; antibiotic susceptibility testing of ocular CoNS. The specimens were collected from the target patients who attended the Microbiology Laboratory of a tertiary care eye hospital in Coimbatore, Tamilnadu state, India. The isolates were subjected to tube and slide coagulase tests for the identification of CoNS. All the isolates were subjected to screening for lipase and protease activities. Screening for other virulence factors viz., slime production on Congo red agar medium and haemagglutination assay with use of 96-well microtitre plates. These isolates were identified upto species level by performing biochemical tests such as phosphatase test, arginine test, maltose and trehalose fermentation tests and novobiocin sensitivity test. The isolates were subjected to antibiotic susceptibility studies, based on the revised standards of Clinical and Laboratory Standards Institutes (CLSI). During the one year of study, among the total 260 individuals who were screened, 100 isolates of CoNS were obtained. Lipolytic activity was seen in all the isolates, whereas 38 isolates showed a positive result for protease. A total of 63 isolates showed slime production. Of 100 isolates, 30 isolates were analyzed for haemagglutination, where 4 isolates showed the capacity to agglutinate the erythrocytes. The results of the biochemical analysis revealed that of the 100 isolates of CoNS, 43% were Staphylococcus epidermidis. The other isolates were identified as S. xylosus (n=8), S. captis (n=16), S. haemolyticus (n=10), S. saccharolyticus (n=2), S. hominis (n=5), S. saprophyticus (n=6) and S. intermedius (n=1). On the other hand, 9 isolates were not identified. In the antibiotic susceptibility analysis, it was found that most of the isolates were sensitive to vancomycin, amikacin and linczolid and resistant to cefatoxime, oxacillin, bacitracin and nalidixic acid. S. epidermidis was found to be predominant in causing the ocular complications. Slime production, heamagglutination, protease and lipase activities could be the putative virulence factors of CoNS. Antibiotic susceptibility patterns of CoNS against antibacterial agents revealed maximum resistance to beta lactam groups, and the resistance was found to be higher to oxacillin, and lowest to vancomycin.

Epidemiological Investigation and Antibiotic Sensitivity of Salmonellosis in Goats at the Selected Areas of Bangladesh

Salmonellosis is one of the life-threating diseases of goat in Bangladesh. Therefore, the present study was designed to study the prevalence of Salmonellosis, and isolation and characterizations of the Salmonella spp. from apparently healthy and diarrheic goat. A total of 47 faces samples were collected from selected place and cultured onto different prescribed medium to isolate it. In this study, 12.76% (6/47) samples were found to be positive for Salmonella spp. During culture on SS agar medium, all of the Salmonella isolates produced round, smooth, opaque, translucent and black color colonies on SS agar media. All of the isolated Salmonella spp. fermented dextrose, maltose and mannitol with production of acid and gas but did not ferment sucrose and lactose. However, these isolates had showed Indole and Voges-Proskauer test negative, Methyl-Red test positive. All of these isolates were subjected to rapid plate agglutination test with polyvalent “O” (Poly ‘O’) and polyvalent “H” (poly ‘H’) antisera where positive agglutination were observed. They were highly sensitive to ciprofloxacin, spiramycin and gentamycin; moderately sensitive to oxytetracyline, streptomycin and amoxicillin; less sensitive to sulphamethoxazole and resistant to penicillin-G. Based on the present findings, it may be concluded that the investigated Salmonella spp. from goats might be S. typhimurium, S. enteritidis, S. brandenburg, S. salford, S. newbrunswick, S. newport or S. dublin. Further study will be needed, therefore it requires further characterization using other serological and molecular techniques.