MOSP - Macao Scientific Publishers

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Survey role of nano structure surface layer in Bacillus cereus strains resistant to antibiotics (Iran-Azzahra Hospital and Esfahan University)

Shila Jalalpour

Abstract: The most common surface structures bacteria are monomolecular crystalline arrays of proteinaceous subunits termed surface layers or S-layers. Since S-layer-carrying organisms are ubiquitous in the biosphere and because S-layers represent one of the most abundant cellular proteins, it is now obvious that these metabolically expensive products must provide the organisms with an advantage of selection in very different habitats. S-layers have been associated with a number of possible functions that relate to pathogenicity. S-layers can function as adhesins, enabling the bacterium to adhere to host cell membranes and tissue surfaces in order to colonize and protect bacteria from harmful enzymes and antimicrobial agents or changes in pH. Bacillus cereus is one of nosocomial infections bacteria. B. cereus produces several potential virulence factors such as S-layer. A total of 274 strains were isolated from staff hand and hospital surfaces of Azzahra-hospital during 2005 to 2007 years. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of S-layer proteins extracted from B. cereus strains by using Tris-HCl (pH 8) showed that the S-layer proteins of different strains isolate of staff hands and hospital surfaces had subunit molecular weight of 97-kDa. Antibiotic susceptibility was performed according to antibiotic susceptibility standard disc diffusion agar. All the statistical analyses carried out using SPSS version 14. Chi-square and fisher test used for determination of significance of association. The p≤ 0.05 was considered significant. From 247 bacteria, frequency of B. cereus strains was 9.49%. From 13 isolated B. cereus of, staff hand 11 strain (84/6%) and from 13 isolated B. cereus from hospital surfaces, 1 strain (7/7%) production S-layer. According to the antibiogram result, S-layer non producer strains, in comparison with S-layer producer strains, were more sensitive to antibiotics. The result showed high prevalence of S-layer producer of B. cereus strains in hospital; and this point is due to the increased antibiotic resistance of nosocomial infections.[...] Read More.

Keywords: S-layer, Bacillus cereus, antibiotic resistant, nosocomial infections.

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Insights on genetic diversity and phylogenetic analysis of Hop stunt viroid (HSVd) population from symptomatic citrus tree in Tunisia

Hamdi I., Elleuch A., Bessaies N. and Fakhfakh H.*

Abstract: Hop stunt viroid (HSVd) variants from cachexia symptomatic citrus tree were subjected to retro-transcription and DNA amplification (RT-PCR), cloning and sequencing. Here we report genetic diversity and phylogenetic analysis of HSVd Tunisian isolate. Our study revealed obvious polymorphism within Tunisian isolates and high similarity with Japanese variants. Neighbor-joining analysis was carried out on the new HSVd-citrus sequences together with 44 previously described HSVd isolates from citrus and one from grapevine. The phylogenetic analysis showed that Tunisian isolates were clustered into 4 different groups (CVd-IIa, b, and c and grapevine group). Furthermore, the predicted secondary structure was scrutinized to be more understanding on how the nucleotide change affects variable (V) and pathogenicity domain (P).[...] Read More.

Keywords: Hop stunt viroid (HSVd), citrus, cachexia, phylogeny, secondary structure, Tunisia.

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Predicting the catalytic sites of Streptomyces clavuligerus deacetylcephalosporin c synthase and clavaminate synthase 2

Hong Soon Chin*, Khang Wen Goh, Kah Cheng Teo, Mun Yee Chan, Seong Wei Lee and Lisa Gaik Ai Ong

Abstract: Enzymes categorized under the 2OG-Fe (II) oxygenase superfamily and Taurine catabolism dioxygenase TauD family demonstrated a striking structural conserveness even with low protein sequence homology. It is evident that these enzymes have an architecturally similar to catalytic centre with active ligands lining the reactive pocket. Deacetoxycephalosporin C synthase (DAOCS), isopenicillin N synthase (IPNS), deacetylcephalosporin C synthase (DACS), clavaminate synthase 1 and 2 (CAS1 and 2) are important bacterial enzymes that catalyze the formation of β-lactam antibiotics. With the advancement of protein structural analysis software, it is possible to predict the catalytic sites of protein that shared a structural resemblance. By exploiting the superimposition model of DAOCS-IPNS, DAOCS-CAS1 and IPNS-CAS1, a computational protocol for predicting the catalytic sites of proteins is now made available. This study shows that without the crystallized or NMR structures of DACS and CAS2, the plausible catalytic sites of protein can be forecasted using this structural bioinformatics approach.[...] Read More.

Keywords: Isopenicillin N synthase (IPNS), deacetoxycephalosporin C synthase (DAOCS), deacetylcephalosporin C synthase (DACS), clavaminate synthase (CAS), 2OG-Fe (II) oxygenase superfamily.

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Microbiological analysis and somatic cell counts in raw milk from farms of SÃ£o Paulo State, Brazil

Full Length Research Paper

Abstract: The objective of the study was to evaluate mesophyle, psychrotroph and somatic cell counts (SCC), and presence of Staphylococcus aureus in raw milk produced in 42 dairy farms of the State of São Paulo. Farms were classified according to milk yield in low (< 400 L/day, n = 17), intermediate (400 - 1,000 L/day, n = 8) and high milk production (> 1,000 L/day, n = 17). Mesophylic bacteria counts were lower (p < 0.05) in high production farms, with no differences (p > 0.05) in psychrotrophic and somatic cell counts between the three categories. S. aureus was more frequent (p < 0.05) in the milk of individual cows in intermediate production farms. Percentage of samples that did not comply with SCC tolerance limits in grade B milk ranged from 29.4 (low production) to 52.9% (high production). Results indicate that the greatest difficulties for dairy farms to comply with milk quality parameters are related to the adoption of hygiene practices during milking and to failures in milk conservation.[...] Read More.

Keywords: Milk quality, mesophyles, psychrotrophs, somatic cell counts (SCC), Staphylococcus aureus.

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Prevalence of typhoid fever in referral hospitals in Umuahia and Aba, Abia State, Nigeria

Elendu C. Onwuchekwa*, Uzochukwu G. Ekeleme, Oliver Onu-Osi, Okonudo, I. Diana

Abstract: The prevalence of typhoid fever in referral hospitals in Umuahia and Aba, Abia State, Nigeria was studied using standard microbiological techniques. A total of 500 subjects within the age range of 1-70 years were enrolled. A total of 229 subjects were infected with a prevalence rate of 45.8%. The males had the highest prevalence rate of 50.9%, while females had a prevalence rate of 41.9%. In Aba, 125 (50.0%) subjects were positive, while 104 (41.6%) were recorded in Umuahia. The age group of 21-30 years had the highest rate of 63.3%. Traders were most affected (62.5%). The stool cultures from males had the highest prevalence of 24.8% in ABSUTH, Aba while females had the lowest of 16.0% in FMC, Umuahia. Hence, health care personnel should not totally depend on widal test alone for the diagnosis of enteric fever but should use other diagnostic methods to differentiate Salmonella infection from other related infections.[...] Read More.

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Characterization and optimization of agarase from an estuarine Bacillus subtilis

S. Saraswathi*, V. Vasanthabharathi, V. Kalaiselvi and S. Jayalakshmi

Abstract: A bacterium producing agarase was isolated from the vellar estuary and potential strain was identified as Bacillus subtilis. The ideal parameters was found to be of pH 8, temperature of 40°C and 3% of NaCl concentration for optimal growth and agarase activity. Agar as carbon source and yeast extract as nitrogen source was found to be suitable for optimum growth and agarase activity. The activity of enzyme obtained from the cell free filtrate was 15.2 U/L and the activity of the partially purified enzyme was 5.3 U/L and the purified enzyme activity was found to be 2.3 U/L. The stability of the partially purified enzyme on pH profile was found to be pH 8 and thermostability was found to be up to 40°C. The purified enzyme was determined to be homogeneous on the basis of SDS PAGE and had a molecular weight of 20 KDa.[...] Read More.

Keywords: Agarase, Bacillus subtilis, optimization, stability, SDS PAGE.

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Killing kinetics and bactericidal mechanism of action of Alpinia galanga on food borne bacteria

Siriporn Okonogi*, Waranee Prakatthagomol, Chadarat Ampasavate and Srikanjana Klayraung

Abstract: The aim of this study was to explore the killing kinetics and bactericidal mechanism of action of A. galanga against food borne bacteria in order to promote this plant as a source of natural preservative. The comparison on antibacterial power was firstly done among its essential oil and the crude extracts obtained from various extracting solvents. The essential oil showed the extremely strongest antibacterial activity and more effective killing activity against Gram negative than Gram positive food borne bacteria. The kinetic time of the oil for complete bactericidal action against E. coli was 40 min whereas that of gentamicin was 120 min. The scanning electron microscopy (SEM) of bacterial morphology after exposed to the oil showed bacterial membrane destruction. It was concluded that the essential oil is the highest potential part of A. galanga against food borne bacteria. Its killing kinetics against Gram negative bacteria was extremely faster than a broad spectrum antibiotic gentamicin. Its mechanism of bactericidal action was along with the bacterial membrane disruption and malfunction leading to cell death.[...] Read More.

Keywords: Alpinia galanga, antibacterial, mechanism of action, essential oil, killing kinetics.

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Seroprevalence of Mycoplasma gallisepticum and Mycoplasma synoviae infection in the commercial layer flocks of the Centernorth of Iran

Payam Haghighi-Khoshkhoo*, Gita Akbariazad, Masood Roohi, Javad Inanlo, Mehran Masoumi and Pedram Sami-Yousefi

Abstract: This survey was carried out to determine the seroprevalence of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) infections in commercial layer farms in Centernorth of Iran. A total of 2000 serum samples were collected from 40 commercial layer flocks (50 samples/ flock) mostly > 40-week-old. Sera tested by serum plate agglutination (SPA) method using commercial MG antigen and MS antigen. Positive reactions retested by SPA on 1:8 dilution and the flocks with more than 10% positive reactions considered positive serologically. The results showed that 4 of 40 (10%) flocks were MG positive and the rest (90%) were negative. About MS, 17 of 40 (42.5%) flocks were positive and 33 of 40 (57.5%) were negative. Sera tested for MG were: 125 of 2000 (6.25%) positive, 1821 of 2000 (91.05%) negative and 54 of 2000 (2.7%) suspect. Sera for MS were: 371 of 2000 (18.55%) positive, 1617 of 2000 (80.85%) negative and 12 of 2000 (0.6%) suspect. Statistical analysis showed a positive correlation between MS positive flocks and strain (LSL flocks compared to Hy-Line flocks) and capacity of the farms significantly (P[...] Read More.

Keywords: Mycoplasma gallisepticum, Mycoplasma synoviae, seroprevalence, serum plate agglutination test.

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Prevalence of extended spectrum beta lactamases (ESBL) in clinical isolates from a teaching hospital in Peshawar, Pakistan

Shahina Mumtaz, Jawad Ahmed*, Liaqat Ali and Hamid Hussain

Abstract: Infections caused by ESBL producing members of the enterobacteriaceae have rapidly increased all over the world. ESBL increase the possibility of failure of empiric antimicrobial regimens. The aim of this study was to determine the prevalence of ESBL in bacterial isolates and to look into the options for treating infections caused by these organisms. A total of 4,150 isolates of enterobacteriaceae were studied. ESBL producer isolates were 371 (8.94%) out of which 281 (75.7%) were recovered from admitted patients while 90 (24.3%) were recovered from outdoor patients. ESBL detection was carried out according to Clinical Laboratory and Standard Institute (CLSI) criteria. Majority of the ESBL producing isolates were obtained from urine 282 (76.0%), followed by swabs 69 (18.6%) fluids 12 (3.2%) blood 06 (1.7%) and sputum 02 (0.5%). The ESBL phenotype was detected in 322 (89.5%) of the isolates of E. coli, 20 (5.4%) of Klebsiella spp. 14 (3.8%) Enterobacter and 05 (1.3%) Citrobacter spp. Carbapenems was the drug of choice for serious infection with ESBL – producing organisms in Peshawar. These should not be administered as empiric therapy, because their over use can result in significant resistance in future.[...] Read More.

Keywords: Extended spectrum beta lactamases (ESBL), cephalosporins, Escherichia coli, phenotype screening.

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Determining the knowledge of food safety and purchasing behavior of the consumers living in Turkey and Kazakhstan

Nevin Sanlier*, Ayhan Dağdeviren, Bülent Çelik, Saniye Bilici and Aktolkin Abubakirova

Abstract: Complete and balanced nutrition with reliable food consists of the basis of health and protective health services. Therefore, the current study was carried out to determine the knowledge of food safety level and purchasing behavior of 668 consumers living both in Turkey (n=348) and in Kazakhstan (n=320) and to compare the results. Volunteered consumers for the research were given a face to face interview between March and September 2010. It was found that the knowledge of purchasing behavior (14.43±2.56) of food safety (20.82±4.20) of the consumers living in Turkey was higher compared to those living in Kazakhstan (11.84±2.92, 14.74±3.86 respectively) and that the difference between the two countries was statistically significant (p[...] Read More.

Keywords: Purchasing behavior, knowledge of food safety, consumer, Turkey, Kazakhstan.

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