Open Access Original Research Article

Cultural Isolation and PCR Based Assay for Detection of flaA gene of Campylobacter jejuni from Acute Diarrheic Patients in Tertiary Care Hospital at Dhaka, Bangladesh

Sushmita Roy, S. M. Shamsuzzaman, Kazi Z. Mamun, Mejbah Uddin Ahmed, Soma Halder

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/BMRJ/2015/19818

Aim: Among bacterial causes of acute diarrhea Campylobacter species is frequently responsible. Campylobacter spp. is the leading agents of bacterial gastroenteritis in developed as well as developing countries. This study was conducted to determine the frequency and antimicrobial susceptibility pattern of Campylobacter spp. isolated from stool sample of acute diarrheic patients.

Study Design: This was a cross-sectional study.

Place and Duration of Study: Two hundred stool samples of children of age between 6 months to 5 years with diarrhea/dysentery were taken from outpatient and inpatient department of Dhaka Medical College Hospital (DMCH) and Dhaka Shishu Hospital from the 1st January, 2011 to 31st December, 2011. The study was carried out at the department of Microbiology, Dhaka Medical College (DMC).

Methodology: The samples were inoculated on Campy-Bap media and MacConkey’s agar media and were incubated at 42°C under microaerophilic conditions. The growth after 48 hours was provisionally identified by colonial morphology, oxidase test, catalase test, Gram staining and motility. The organisms were identified to species level by hippurate hydrolysis and resistance to cephalothin. All isolates of Campylobacter jejuni by using conventional bacteriological method were also positive using the Polymerized Chain Reaction (PCR) assay by detecting flaA gene specific for Campylobacter jejuni. Susceptibilities of 27 Campylobacter isolates were determined for seven antimicrobial drugs using the disk diffusion assay.

Results: Using conventional bacteriological methods, 27(13.5%) of 200 stool samples were positive for Campylobacter spp. Among isolated Campylobacter sppCampylobacter jejuni was (88.89%); the remaining isolates were Campylobacter coli (11.11%). Peak age of children with Campylobacter spp. infection was 6-12 months. The male and female ratio was 1.5:1. Resistance to co-trimoxazole was the most common finding, followed by resistance to nalidixic acid, and ciprofloxacin.


Open Access Original Research Article

Molecular Analysis of Staphylococcus aureus Infections in Trinidad and Tobago

Patrick E. Akpaka, Rashida Roberts, Stefan Monecke

Microbiology Research Journal International, Page 1-10
DOI: 10.9734/BMRJ/2015/21376

Aims: Previous studies regarding Staphylococcus aureus in Trinidad and Tobago have so far been conducted mainly on methicillin resistant S. aureus (MRSA) isolates. Few reports are available regarding S. aureus infections in the country. This study was therefore designed to determine the unique molecular epidemiology and characteristics of S. aureus infections both in the community and hospitals in the country. 

Materials and Methods: During a 10 month period, 385 persons who had infections caused by S. aureus were reviewed. Standardized questionnaires were utilized to obtain demographic data of the infected individuals from three major tertiary hospitals; and 309 S. aureus isolates recovered from these individuals were analysed using conventional and molecular microbiological methods including DNA microarray and multi locus sequence typing (MLST).

Results: Skin and soft tissue infections (SSTI) were the most prevalent type of S. aureus infections, followed by blood stream, urogenital tract and respiratory tract infections. Results also revealed that surgical, paediatric and medical wards experienced most of the S. aureus infections in a hospital setting or environment. The most prevalent S. aureus clonal complex (CC) associated with infections was CC8, which were methicillin sensitive and also positive for the Panton-Valentine leukocidin (pvl) genes - (CC8-MSSA-PVL+). Generally, the pvl genes rate among the isolates was observed to be 47% while MRSA now stands at 13.6%. The most prevalent MRSA strains were ST239-MRSA III and ST8-MRSA IV (USA300).

Conclusions: There is a high diversity of S. aureus clonal complexes infections in the country and the pvlgenes which were considered rare are now highly prevalent. Methicillin resistance though slightly higher than previously reported does not represent a significant increase. We propose that surveillance efforts should continue to be directed to monitor S. aureus infections in hospitals in the country so as to detect and eliminate any possibility of its outbreak early in the country as currently practiced in other countries.


Open Access Original Research Article

Concomitant Detection of Biofilm Formation and MBL Production in Meropenem Resistant Isolates of Pseudomonas aeruginosa

Shivani Saxena, Gopa Banerjee, Rajiv Garg, Mastan Singh, S. K. Verma, R. A. S. Kushwaha

Microbiology Research Journal International, Page 1-6
DOI: 10.9734/BMRJ/2015/19836

The purpose of this study was to detect biofilm formation and to examine the correlation between biofilm and Metallo-β-lactamases (MBL) production in Pseudomonas aeruginosa. A total of 64 P. aeruginosaisolates were identified using standard microbiological methods and antimicrobial susceptibility testing (AST) was performed on them according to Clinical and Laboratory Standards Institute (CLSI) guidelines. The isolates were screened for biofilm production using both qualitative and quantitative methods. The presence of MBL genes were checked by multiplex PCR assay.  Out of all 30 meropenem resistant P. aeruginosa, 2 isolates were found producing all the three genes (i.e. blaIMPblaVIMblaSIM) for MBL production and they were found to produce biofilm. Resistant to four antibiotics such as aztreonam (85.7% vs 11.1%, P< 0.000), Cefepime (82.1% vs 2.8%, P<0.000) gentamycin (82.1% vs 27.8%, P< 0.000) and Pipercillin/Tazobactum was also high (28.6% vs 2.8% P< 0.003) was comparatively higher among biofilm producers than non biofilm producers. In biofilm production, both qualitative method and quantitative plate method showed 16 isolates (53.3%) as biofilm producers for MBL genes. Out of these 16, only 9 isolates showed MBL production along with biofilm production having significant association (P<0.004).

The prevalence of MBLs has been increasing worldwide, particularly among P. aeruginosa, leading to severe limitations in the therapeutic options for the management. Presence of MBL genes has a role in inducing biofilm production and significant association in P. aeruginosa isolates. Overall, drug resistance was found to be more in biofilm producing isolates than non biofilm isolates.


Open Access Original Research Article

Pulmonary Paragonimiasis and Aspergillosis in Patients Suspected of Tuberculosis in Yaounde, Cameroon

Anna Longdoh Njunda, Dickson Shey Nsagha, Jules Clement Nguedia Assob, Baiye William Abange, Azemtsop Julius Tamoh, Tebit Emmanuel Kwenti

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2015/20138

Aims: The purpose of this study was to determine the prevalence of paragonimiasis and aspergillosis in patients suspected of pulmonary tuberculosis in Yaounde.

Study Design: Cross sectional study.

Place and Duration of Study: Participants were recruited between March and June 2014 using the tuberculosis treatment centers of the University Hospital Center and Jamot Hospital Center of Yaounde

Methodology: Two sputum samples were collected from participants and analysed using standard microbiological methods.

Results: A total of 260 patients were enrolled, 131 (50.4%) females and 129 (49.6%) males. Of the 260 samples collected, Mycobacterium tuberculosis was detected in 44 (16.92%) [CI: 12.33–21.51], Aspergillus spp. in 42 (16.15%) [CI: 11.65–20.66] and Paragonimus africanus in 7 (2.69%) [CI: 0.7 – 4.67]. Aspergillosiswas more prevalent in the age group 41-60years 29 (44.62%) (= .000) and among builders 19 (45%) (P = .013). Isolates of Aspergillus included A. fumigatus 20 (47.62%), A. flavus 10 (24%) and A. niger 10 (24%). Other pathogens isolated included Candida albicans 80 (39.8%) and Histoplasma capsulatum var duboisii 21 (8.1%). Nine (3.46%) and 20 (7.69%) of patients with tuberculosis were coinfected with Aspergillus spp., and Candida albicans respectively. No coinfection was observed between Mycobacterium tuberculosis and Paragonimus africanus. Gram staining revealed that 20 (7.7%) were positive for fungal elements, 80 (30.8%) for yeast, 5 (1.9%) for yeast and Gram positive rods, 40 (15.4%) for Gram negative rods and 30 (11.5%) for Gram positive cocci.

Conclusion: This study demonstrates varying prevalence of Aspergillus spp., Paragonimus africanus in patients suspected of tuberculosis in Yaounde. Other potential pathogens isolated included Candida albicans, and Histoplasma capsulatum var duboisii. Further studies will be required to shed more light on the biology and transmission of Paragonimus africanus in Yaounde.


Open Access Original Research Article

Antibiotic Sensitivity Pattern of Aerobic Bacterial Isolates in Wound Infections in Navi Mumbai, India

Nitin Goel Insan, Anahita V. Bhesania Hodiwala, Ravi Vashisth, Amod Yadav, Mahesh Danu

Microbiology Research Journal International, Page 1-6
DOI: 10.9734/BMRJ/2015/5414

Background: Wound infection is a breach in the integrity and protective function of the skin. Mostly bacteria (e.g. Staphylococcus aureus), certain viruses (e. g. Herpes virus) and fungi (e.g. Candida albicans) are responsible for wound infection. This study was conducted for isolation, identification and antibiotic sensitivity testing of aerobic bacterial strains from wound infection.

Methods: Total 216 pus samples were collected and immediately inoculated on Blood agar and MacConkey agar plates. Then the culture plates were placed in incubator at 37°C for 24 hours. After incubation, all isolates were identified by using Gram staining and different biochemical tests. Antibiotic sensitivity test was performed on Mueller Hinton agar plate by Kirby Bauer Disc Diffusion method as per CLSI guidelines.

Results: Among 216 samples, 166 (76.8%) showed positive growth. Fifteen different bacterial species were isolated. The most commonly isolated organism was Staphylococcus aureus (26.7%) followed by Pseudomonas sp. (16.4%), Escherichia coli (11.9%), Klebsiella sp. (7.8%). Antibiotic sensitivity test showed that the most effective antibiotics for Gram positive bacteria were Linezolid (87.2%) and Ampicillin + Sulbactam (82.3%) whereas Cefotaxime (48%) was the least effective antibiotic. The most effective antibiotic for Gram negative isolates was Amikacin (72.3%) followed by Netilline (67.3%). Cefuroxime (21.9%) was the least effective antibiotic for Gram negative bacteria.

Conclusion: Staphylococcus aureus was the most frequently isolated bacteria in wound infection. Linezolid and Amikacin were the most effective antibiotics for Gram positive and Gram negative bacteria, respectively.


Open Access Review Article

Analyzing Different Acetyl Co-A Metabolizing Enzymes as Potential Drug Targets against Mycobacterium tuberculosis

Shamim Akhtar, Sheetal Singh, Santosh Kumar, Dhiman Sarkar

Microbiology Research Journal International, Page 1-15
DOI: 10.9734/BMRJ/2015/19032

Mycobacterium tuberculosis, the causative agent of tuberculosis, is responsible for the deaths of million people around the globe. The scenario is worse than ever due to the emergence of drug resistant strains which are widely spread throughout the globe in much faster ways. To control this worst situation, we need to speed up the search for novel drugs which can specifically kill drug resistant bacteria in collaborative ways amongst academic, clinician and industry. Among different metabolic pathways, fatty acid synthesis pathway has always been a very attractive area for the drug target because of its crucial role during the infection and further in long term survival of pathogen inside the human host. In this review article, we analyzed the role of important and crucial enzymes, which are responsible for the influx and efflux of acetyl co-A substrate, a central hub of metabolites, as potential drug targets against M. tuberculosis.