Open Access Original Research Article

Molecular Detection of Panton Valentine Leukocidine Gene among Beta-lactamase Producing Staphylococcus aureus Isolated from Clinical Samples in Ondo State, Nigeria

C. O. Esan, O. M. David, O. Famurewa

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/BMRJ/2016/18278

Background: In recent time Staphylococcus aureus has been implicated not only in hospital-acquired but also in community-acquired infections. Some clonal types of S. aureus that produce   β-lactamase have evolved. Panton-Valentine leukocidine (pvl) gene among β-lactamase-producing S. aureus from clinical samples in Ondo State, Nigeria has not been reported; hence the objective of this study.

Methods: Clinical samples were collected from secondary and tertiary hospitals in the study area. Amplification and detection of nuc gene was used to confirm the identity of the isolates while polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) of the coagulase gene and pulsed field gel electrophoresis (PFGE) were further carried out on the isolates. Production of β-lactamase was also detected in the isolates using iodometric method while disc diffusion method was used to determine the sensitivity of the isolates to selected antibiotics. The presence of pvl genes among the β-lactamase producers was detected by PCR.

Results: A total of 58 isolates were biochemically confirmed as S. aureus out of which only 21 were β-lactamase producers. Out of the 21 β-lactamase-producing isolates 90.48% (n=19) possessed the nuc gene. Molecular screening of the isolates showed that only one out of the isolates did not possess the coagulase gene. Nine out of the isolates possessed pvl gene among β-lactamase-producing S. aureus. All the isolates were resistant to penicillin and tetracycline while 33.3% and 19.04% were resistant to chloramphenicol and erythromycin respectively. Oxacillin, cefoxitin, clindamycin and fusidic acid completely inhibited the growth of the isolates. Gentamicin and ciprofloxacin were effective on only 4.76% of the isolates.

Conclusion: The prevalence of oxacillin resistance among S. aureus is very low.

Open Access Original Research Article

Frequency and Molecular Characterization of β-lactamases Producing Escherichia coli Isolated from North of Palestine

Ghaleb Adwan, Aws Abu Jaber Jaber

Microbiology Research Journal International, Page 1-13
DOI: 10.9734/BMRJ/2016/22631

Aims: The aim of this study was to determine the prevalence and molecular characterization of AmpC β-lactamases and extended-spectrum β-lactamases (ESβLs) among E. coli isolates.

Place and Duration of Study: Department of Biology and Biotechnology, An-Najah National University, Palestine, during February-April 2015.

Methodology: A total 52 isolates of E. coli were recovered from different hospitals and private labs in Jennin district-Palestine. These isolates were used to detect ESβLs and AmpC β-lactamases using phenotypic tests and molecular techniques.

Results: The prevalence of ESβLs and AmpC β-lactamases using conventional methods was 32.7% and 26.9%, respectively. Whereas, the prevalence using PCR technique was 67.3% and 5.8% for ESβLs and AmpC β-lactamases, respectively. TEM gene was the dominant (82.9%) among E. coli that carried ESβL genes. Other genes were (0.0%), (2.9%) and (15.4%) for CTX-MSHV and OXA genes, respectively. Whereas, AmpC β-lactamases only DHA gene was detected and the prevalence was (5.8%). Molecular analysis by construction phylogenetic tree showed that all sequenced TEM, SHV, OXA and DHA genes were belonged to TEM-1, SHV-1, OXA-1 and DHA-1, respectively. ERIC results showed that these strains were diverse and unrelated clones.

Conclusions: Our results showed high frequency of ESβLs and AmpC β-lactamases among E. coli isolates in Palestine. According to these results we recommend the continuous monitoring and surveillance of the prevalence, proper control and prevention practices and effective antibiotic use will limit the further spread of Amp-C β-lactamases and ESβLs producing isolates within hospitals in Palestine.

Open Access Original Research Article

Identification, Comparison, and Transfer of the pxo Gene between Members of Bacilli Species

Shahcheraghi Seyed Hossein, Namazi Mohammad Javad, Nouruzi Jamileh, Lotfi Marzieh, Hojatoallah Moradi, R. Golmohammadi

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/BMRJ/2016/19130

Aim: Bacillus anthracis causes anthrax in which the pxo gene and its associated plasmids, pXOP1and pXO2, encode toxin and capsule proteins, both of which are involved in the pathogenicity of anthrax. The possibility of transferring the pxo gene to other bacilli has recently been shown. The main aims of this study were to identify and compare the frequencies of the pxo gene in isolated bacilli members. The study examined possible pxo gene transfer from B. anthracis to other closely related members of the genus Bacillus. The findings presented here may be useful in the study of vaccination.

Study Design: The study design was cross-sectional and descriptive. Sixty-five soil samples were collected from different geographical regions in Iran.

Place and duration of study: The study was conducted in many provinces in Iran over several months. Samples were analyzed at the Mashhad University of Medical Sciences.

Methodology: Organisms were isolated from the soil, and the isolation of pXO plasmid was performed. Presence of the pXO1 plasmid was confirmed by agarose gel electrophoresis. Isolated proteins from each bacillus were examined by SDS-PAGE. The limits of proteins encoded by the pxo gene were specifically located and data were statistically analyzed using excel.

Results: Results showed that 13 samples out of 38 bacilli contained the plasmid of interest and protein bands related to proteins coded by the pxo gene.

Conclusion: We have determined that the pXO1 plasmid has been transferred from B. anthracis to 13 other isolates of B. cereus group members in different regions in Iran. No transfer of the pXO2 plasmid was observed. This was apart from the identification of the pxo gene and its plasmids in different members of bacilli.

Open Access Original Research Article

Antibiotic Resistance Patterns and Plasmid Profiles of Escherichia coli Isolates from Clinical Specimens

Adnan S. Jaran

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/BMRJ/2016/22367

Aim: The primary aims of this study were to investigate antibiotic resistance patterns and plasmid profile of antibiotic resistant Escherichia coli isolated from clinical specimens, and to find out a possible correlation between plasmids and antibiotic sensitivity patterns.

Methodology: Unrelated E. coli strains were isolated from different clinical specimens from different hospitals and primary health care centres in the Riyadh area Saudi Arabia. Antimicrobial susceptibility of E. coli isolates was determined using disc diffusion method against 12 com­monly used antimicrobial drugs. Plasmid DNA was extracted from lysed E. coli cells using Plasmid Miniprep kit, and visualised using Agarose gel electrophoresis.

Results: The results showed that isolated strains of E. coli were resistant to Cotrimoxazole (70%), Ampicillin (67%), nalidixic acid (51%), Cephalothin (27%), Agumentin and Nitrofurantoin (19%), Tetracycline and Ciprofloxacin (15%) and Gentamycin (12%). Plasmid analysis of clinical isolates showed the presence of 1 to 7 plasmids with size range of 1.9 to 21.1 Kb, as compared to control E. coli ATCC 25922 (size range of 2 to 19.5 Kb).

Conclusion: The results obtained in this study showed no direct correlation between the patterns of antibiotic resistance and plasmid profiles.

Open Access Original Research Article

Colonization Pattern of Rhodotorula sp. in Polluted Tilapia Fish Aquaria and the Risk of Rhodotorula Caused Infection

A. I. Sanusi, D. V. Adegunloye, A. M. Orimoloye, T. M. Olorunnusi

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/BMRJ/2016/20411

In this study, the trend of colonization of e-waste soil polluted fish aquaria by Rhodotorula sp was monitored. The aquaria containing the specie Oreochromis niloticus were polluted separately with different quantities of soil from e-waste dumpsite and the soil without e-waste. The soil sample from e-waste dumpsite differs from soil without e-waste in all of the parameters determined. Higher organic contents (17.60%), moisture content (3.86%), organic carbon (10.17%) and higher value of organic nitrogen (0.35%) were recorded. Four species of fungi were isolated from soil of e-waste dumpsite while two species of fungi were isolated from soil without e-waste. Rhodotorula presence in the aquaria was only observed in the first and second week of the research. The highest isolation was from the aquarium polluted with 75 g of soil without e-waste (34 isolates) at week one while the lowest was from the control aquarium (15 isolates) also at week one. It was also observed that plates and week where Rhodotorula sp population was high, the populations of other fungi were lower. Most of the other fungi isolated within the two weeks period of Rhodotorula colonization were inversely proportional to the population of Rhodotorula sp. The pH values and the biochemical oxygen demand were significantly affected by the pollutant. The momentary colonization of the aquaria by Rhodotorula sp, posed health risk to both the living organisms in the aquaria and human having contact with the aquaria while the antagonistic effect on other fungi could lead to imbalance in the fungi community in the aquaria.


Open Access Original Research Article

High Prevalence of Bacterial Pathogens in Sputum of Tuberculosis Suspected Patients in Buea

Serge Ngekeng, Benjamin Thumamo Pokam, Henry Dilonga Meriki, Anna Longdoh Njunda, Jules Clement Nguedia Assob, Irene Ane-Anyangwe

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/22426

Aim: To investigate the prevalence of non AFB (acid fast bacilli) bacterial pathogens among HIV positive and HIV negative TB suspected patients.

Study Design: A cross sectional laboratory based study was used.

Place and Duration of Study: Tuberculosis Unit, Buea Regional Hospital, between February and May 2015.

Methodology: We included 145 TB suspected patients referred to do a sputum test (82 women, 63 men, 44 HIV positive, 101 HIV negative, age range 21-70 years). Socio-demographic factors and clinical history were abstracted using structured questionnaires. One early morning sputum sample was examined microscopically and cultured on blood, chocolate and MacConkey’s agars

Results: Non AFB bacterial infections were identified in 89 (61.4%) out of the 145 study participants. The prevalence of non AFB bacterial infection in the HIV positive group (33 0ut 0f 44) was significantly higher than in the HIV negative group (56 out of 101), (P= .032). Bacteria isolated included 42 S. pneumoniae, 19 H. influenzae, 15 K. pneumoniae, 14 other enterobacteriaceae, 11 P. aeruginosa and 7 S. aureus. Although the prevalence of bacterial infection was 67.1% in females and 54% in males, the difference was not statistically significant (P =.149).

Conclusion: There is a high prevalence of non AFB bacterial pathogens among TB suspected patients. HIV positivity significantly increased the risk of developing LRTIs.