Open Access Short Research Article

Diluent Mitigates the Inhibitory Effect of Zinc Oxide Nanoparticles on Escherichia coli and Staphylococcus aureus

Samuel Eduok, Naomi Asamudo

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/23252

The effects of zinc oxide nanoparticles on Escherichia coli and Staphylococcus aureus in deionized water, normal saline and phosphate buffered solution were investigated based on culture-dependent growth response. After 6 h incubation in phosphate buffered solution, the 10, 100 and 1000 µg mL⁻ˡ treatment resulted in a range of 1.0 to 1.5 log reduction in growth of E. coli and S. aureus compared with the control. In the normal saline, 1.1 to 3.3 and 1.1 to 3.6 log reduction whereas 1.2 to 4.1 and 1.2 to 3.8 log reduction in deionized water was observed for E. coli and S. aureus respectively. Inhibitory effect of ZnO nanoparticles on the organisms in the diluents was concentration-dependent with 1.8 to 2.6 times higher viability of E. coliand S. aureus in PBS compared to the normal saline and deionized water, but the difference was significant (P = .05). The evidence suggests differential susceptibility of E. coli and S. aureus to ZnO nanoparticles in diluents routinely used in microbiological assay and raises concern on the challenges of interpreting the inhibitory effect in culture-dependent microbiological analysis. Compared with deionized water and normal saline, phosphate buffered solution mitigated the inhibitory effect of ZnO nanoparticles on the growth dynamics and population density of E. coli and S. aureus.


Open Access Short Research Article

Serum Levels of Immunoglobulin A, G & M in Chlamydia trachomatis Infection among Primary and Secondary Infertility Patients

Dele-Ochie Patricia Ejenawome, Ifeanyichukwu Martin Ositadinma, Ngwu Amauche Martina, Ebunu Ezekiel

Microbiology Research Journal International, Page 1-6
DOI: 10.9734/BMRJ/2016/23106

Background: Chlamydia trachomatis is a well- known sexually transmitted bacteria that is capable of damaging female reproductive tract leading to infertility. Chlamydia trachomatis infection in men can mechanically hinder sperm from reaching female reproductive tract.

Aim: The aim of this study is to determine the serum levels of immunoglobulin (Ig) IgA, IgG & IgM in clinically diagnosed primary and secondary infertile patients that tested positive to Chlamydia trachomatis IgG antigen.

Study Design: In this case control study, two hundred male and female patients that visited Government hospital Ekpan due to inability to achieve pregnancy after a period of one year unprotected sexual intercourse were randomly selected for the study.

Place and Duration of Study: Government Hospital Ekpan, Delta state, between June, 2013 and August, 2013.

Methodology: Two hundred patients (104 men, 96 women; age range 18-45 years) that are clinically diagnosed with primary and secondary infertility and hospital staff (23 men, 27 women; age range 18-45 years) with no history of infertility were included. Chlamydia assay was done by Enzyme Immunosorbent Assay (EIA). IgA, IgG & IgM determination were done by Immunoturbidimetric method.

Results: The result of this study showed that the mean +/- SD of IgG g/dl in male infertility due to positive Chlamydia trachomatis infections; 301.22 +/- 43.86 g/dl, negative Chlamydia trachomatis infections; 333.14 +/- 40.08 g/dl and fertile male 337.09 +/- 40.89 g/dl were compared. The result showed statistically significant difference (F= 9.96; P= 0.05). Also the mean +/- SD of Immunoglobulin G (IgG) in female infertility due to combined effect of positive Chlamydia trachomatis infection; 154.81 +/-  60.12 g/dl, negative Chlamydia trachomatis infection; 184.54 +/- 63.33 g/dl, and fertile female control; 137.96 +/- 87.11 g/dl  without infertility were compared. The result showed statistically significant difference (F= 3.32; P= 0.05).

Conclusion: Chlamydia trachomatis bacteria are one of the causes of infertility in patients diagnosed of primary and secondary infertility at Government Hospital Ekpan.

Open Access Original Research Article

Strain Development of Aspergillus brasiliensis Using Physical and Chemicals Mutagenesis for Possible Overproduction of Xylanase, Amylase, Protease and Cellulase under Submerged Fermentation (SmF)

Muna Hassan Abduljubar

Microbiology Research Journal International, Page 1-19
DOI: 10.9734/BMRJ/2016/22953

Aims: Xylanase is commonly involved in the complete hydrolysis of xylan which consisted of hemicelluloses and celluloses as important components of plant cell wall. This enzyme is essential in wide range of applications in various industries along with other hydrolytic enzymes such as amylase, protease and cellulase. Microbial enzymes including xylanase possess several advantages over the use of conventional chemical catalysts due to greater catalytic activity, larger amount of production, higher degree of substrate specificity, higher economical viability and better biodegradable ability without destructive threat to the environment. Global enzymes market is expected to rise to USD millions by 2020. Due to the potential and bright future prospects of these microbial enzymes in biotechnological applications, random mutagenesis that is one of the potential approaches to produce enzymes with positive motivating characteristics is proposed and implemented. Therefore, the present study was aimed to create mutants of Aspergillus brasiliensis using physical and chemical random mutagenesis and to elucidate possible overproduction of xylanase, amylase, protease and cellulase by mutants of A. brasiliensis under submerged fermentation (SmF).

Methodology: In this study, A. brasiliensis that has been classified as GRAS (generally regarded as safe) was subjected to physical mutagenesis of ultraviolet (UV) irradiation and chemical mutagenesis of nitrous acid (NA) and ethyl methane sulfonate (EMS) before screened for the possible overproduction of xylanase, amylase, protease and cellulase in SmF using wheat bran (agro-industrial residual) and yeast extract as the carbon and nitrogen source at the initial medium pH of 6.50 under the optimised growth conditions at 150 rpm at 30°C for prolonged 168 h of fermentation.

Results: Based on the results, xylanase possessed as the highest maximum production of enzyme was notably observed at the optimum fermentation period of 72 h produced by EMS-mutated mutant of A. brasiliensis. Interestingly, 2 mg/mL of EMS was exerted as the optimum chemical mutagen followed by UV irradiation of 254 nm from a distance of 20 cm and lastly 0.17 mg/mL of NA. In fact, the maximum xylanase activity of 11.325±0.881 U/mL was attained after A. brasiliensis exposed to EMS for 45 minutes. On the other hand, the UV treated mutant of 30 minutes produced 10.052±0.987 U/mL of xylanase activity. Lastly, 9.127±0.410 U/mL of xylanase activity was obtained from NA treated mutant for 15 minutes compared to the wild type with 7.821±1.460 U/mL. The xylanase activity in mutants exposed to EMS, UV and NA was notably increased by 45%, 29% and 17% compared to the wild type. On the other hand, the enhancement in amylase activity was also observed in two mutants after UV exposure for 25 minutes and EMS treatment for 60 minutes with the production of 0.481±0.007 U/mL and 0.304±0.040 U/mL compared to wild type with 0.232±0.021 U/mL, respectively. Notably, there were increment of 107% and 31% in activity in mutants compared to wild type. Nevertheless, no possible overproduction of protease and cellulase was detected after the physical and chemical mutagenesis in this study.

Conclusion: In a nutshell, the mutants of A. brasiliensis with enhanced production of xylanase and amylase were anticipated to fulfill the industrial demand in more economical approach using agro-residual waste of wheat bran under SmF.

Open Access Original Research Article

Prevalence of Hepatitis B Viral Markers among Suspected Liver Disease Patients Attending Lagos University Teaching Hospital, Nigeria

A. B. Ajide, L. Y. Adogo, S. A. Omilabu

Microbiology Research Journal International, Page 1-5
DOI: 10.9734/BMRJ/2016/23072

Aim: To determine the different outcomes of HBV infections among patients attending Lagos State University Teaching Hospital.

Place and Duration of Study: This study was conducted in Lagos University Teaching Hospital Idi Araba and College of Medicine University of Lagos, between June 2010- July 2011.

Methodology: A total of 87 samples were collected from suspected liver disease patients aged between 11 and 74 at the gastroenterology clinic, Lagos University Teaching Hospital (LUTH), Idi-Araba. These were screened for hepatitis B virus markers (HBsAg, HBeAg, and HBcIgM) using DIA. PRO DIAGNOSTIC BIOPROBES Srl.

Results: Out of the number screened, 39 (44.8%) were positive for at least one marker and 17 (19.5%), 3 (3.5%) and 19 (17.5%) were positive for HBsAg, HBeAg and HBcIgM respectively.

Among the positive research participants, 18 (20.7%) and 5 (5.8%) were positive for males and females respectively and the difference between them was statistically significant (P<.001).

The highest prevalence rate of (18.4%) was recorded within the age group 31-40. On the basis of sex, the prevalence rate was higher in males 14 (16.1%) than females 2 (2.3%).

Moreover, the prevalence of the markers was stratified by sex and HBcIgM had the highest prevalence among the respondents with the males having higher prevalence 15 (17.2%) than female 4 (4.6%).

Conclusion: This study suggests that screening for all the three markers is a useful tool for the diagnosis and monitoring of HBV infection. More importantly, efforts should be directed at early detection of HBV infection, other agents and effect of such other agents on the progression of HBV infection.

Open Access Original Research Article

Antibacterial Activity of Commercially Available Plant Extracts on Selected Campylobacter jejuni Strains

D. O. Sivasankaran, G. S. Kumar-Phillips, N. C. Rath, J. Marcy, M. F. Slavik

Microbiology Research Journal International, Page 1-13
DOI: 10.9734/BMRJ/2016/23810

Campylobacter jejuni causes over 99% of the foodborne infections associated with Campylobacter in the United States. This study involves evaluation of commercially available plant extracts of oregano, green tea, hawthorn and curcumin against four isolates of C. jejuni. Initial studies were first carried out in broth cultures to determine the general effectiveness of the extracts. The study then was carried out on chicken breast meat to determine the effect of the plant extracts in marinades. Cell counts were determined at intervals of 0, 2, 6 and 24 hours and bacterial viability was determined using different concentrations of the above extracts. Both oregano and green tea extracts were found to be antibacterial even at low concentrations in broth cultures and killed all bacteria in 24 hours. But as marinades on chicken breast meat, the extracts were found to be effective only at higher concentrations. No significant differences were found in the antibacterial effects of the extracts on different C. jejuni strains. These results demonstrate that commercially available plant extracts such as oregano and green tea have potential to reduce and/or eliminate C. jejuni in chicken meat.

Open Access Original Research Article

Studying the Immune Profile and Susceptibility to Microbial Infections in Obese Adults

Mohammad A. K. Al-Saadi, Hadeel F. Farhood, Fouad Q. J. Al-Zayadi

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/23752

Objectives: This study aims at studying the effect of adult obesity on immunologic profile and susceptibility to microbial infections.

Materials and Methods: This work was applied on 50 obese subjects visited to the Nutrition Center of Marjan hospital in Babylon province-Iraq from October 2014 to January 2015. The samples were consisted of 39 females and 11 males with age range 20-60 years. This study involved also 30 apparently health subjects with normal weight as controls consisted of 21 males and 9 females with age range 22-50 years. Body mass index for each subject was estimated as obesity determinant, then blood samples were collected from obese and control to estimate the concentrations of interleukin-2 (IL-2), interferon-gamma (IFN-γ), C3 & C4 complement components, and phagocytic index. Also, estimation of anti-streptolysin-O (ASO) & anti-measles-IgG concentrations were used as indicators for microbial infections.

Results: The result of IL-2 was significantly (p˂ 0.05) lower in obese subjects than controls, while IFN-γ was not significant decreased in obese group, while concentrations of C3 & C4 were a highly significant increased (p˂0.001) in obese group, phagocytic index was a highly significant decreased in obese subjects (p˂0.001). Regarding the susceptibility to microbial infections the concentrations of ASO & anti-measles virus IgG in obese group were a highly significant more than controls.

Conclusions: This result may provide clear evidence that obese subjects are more susceptible to microbial infections than normal subjects.