Open Access Minireview Article

Aerosols in Dental Practice- A Neglected Infectious Vector

N. Raghunath, S. Meenakshi, H. S. Sreeshyla, N. Priyanka

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/24101

An aerosol is a suspension of solid or liquid particles in air or other gaseous environment. Sources of bacterial aerosols exist within and outside the dental clinic. The generation of bacterial aerosols and splatters appears to be highest during dental procedures. The use of rotary dental and surgical instruments and air-water syringes generates visible infectious spray, that enclose large-particle spatter of water, saliva, microorganisms, blood, and other debris. Several infectious diseases could be transmitted to staff and patients by airborne bacterial and other contaminants in the dental clinic. The vigilant use of barriers along with appropriate immunizations procedures could safe guard the dental fraternity from the ill-effects of the aerosols.

Open Access Original Research Article

Molecular Identification of Candida dubliniensis among Candida albicans Isolated from Oral Cavity of Cancer Patients using PCR-RFLP, in a Tertiary Care Hospital in Kashmir, India

Abiroo Jan, Gulnaz Bashir, Bashir A. Fomda, Akeela Fatima, Mohammad Suhail Lone, Shugufta Roohi

Microbiology Research Journal International, Page 1-7
DOI: 10.9734/BMRJ/2016/25465

Aims: To retrospectively evaluate 186 stock strains of C. albicans strains isolated from oral cavity of HIV negative patients with various malignancies for the presence of C. dubliniensis isolates among them by PCR-RFLP.

Place and Duration of Study: Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, between October 2013 and October 2014.

Methodology: This study included 186 stock strains of C. albicans tentatively identified by phenotypic methods like germ tube formation in human serum, colony color on chromogenic candida differential agar, characteristic morphology on corn meal agar and assimilation of sugars isolated from HIV negative patients with various malignancies. DNA extraction was performed by chemical method. PCR amplification of ITS1-5.8S-ITS2 rDNA region was achieved using the ITS1 and ITS4 primer pairs which amplify the ITS region of both species, providing a single PCR product of expected size (540 bp). There is no visible difference between these two species with regard to their ITS PCR products. Digestion of amplified products was performed by using restriction enzyme BlnI (AvrII) which cleaves DNA where there is a CCTAGG sequence. The products of digestion generate one band of 540 bp for C. albicans, and two bands of 200 bp and 340 bp for C. dubliniensis because BlnI has one recognition site within the ITS region of C. dubliniensis, whereas none within that of C. albicans.

Results: Of the 186 isolates tested, no C. dubliniensis was found by PCR-RFLP.

Conclusion: Our results of not finding C. dubliniensis in this subset of patients support the need for further investigations into the prevalence of this species among other clinical samples and other susceptible patient populations.

Open Access Original Research Article

Comparison of Automated System Vitek-2 with Conventional Methods, for Identification and Antibiotic Sensitivity in Gram Negative Organisms

Nayeem-u-din Wani, Mohd Suhail, Dalip Kakru, Nargis Bali, Amrish Kohli, Junaid Ahmad

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/24999

Background: Rapid bacterial identification and susceptibility testing improves patient therapy and outcome and decreases emergence of resistance. There is a need to provide rapid, efficient and accurate system for identification and antimicrobial susceptibility testing of pathogens. In this regard the automated identification/AST systems aid in rapid diagnosis/treatment of bacterial pathogens.

Aim: Comparison of automated system Vitek-2 with conventional methods, for identification and antibiotic sensitivity in Gram negative organisms.

Settings and Design: This was a prospective study conducted in the Department of Microbiology at SKIMS, Srinagar, for eight months.

Materials and Methods: A total of 135 non duplicate isolates of gram negative bacteria were included. Organisms were processed on the Vitek-2 system and by manual methods (ID/AST) for comparison.

Statistical Analysis Use: Descriptive statistics (frequency and percentage) was used.

Results and Conclusions: Vitek-2 misidentified 6 isolates of S. typhi as E. coli, K. oxytoca (3 isolates) misidentified as K. pneumoniae, Citrobacter braakii (1 isolate) falsely reported as Citrobacter freundii, Acinetobacter baumannii (2 isolates) misidentified as Acinetobacter lwofii. No minor error (mE), major error (ME) or very major error (VME); with 100% categorical agreement (CA) was seen with ampicillin+sulbactam, piperacillin+tazobactam, ceftriaxone, cefepime, gentamicin, amikacin, levofloxacin, meropenem, colistin, co-trimoxazole, tetracycline, carbenicillin and tobramycin for various Gram negative organisms tested.however errors were seen with E. coli for ampicillin and imipenem. Likewise with K. pneumoniae, errors were seen for a ME for ciprofloxacin and imipenem. Also with P. aeruginosa, errors were seen for ceftazidime, ciprofloxacin and imipenem. No VME was seen for these antibiotics.

Open Access Original Research Article

Microbiology of Chronic Otitis Media

O. J. Akinjogunla, N. O. Eghafona, O. K. Fatunla

Microbiology Research Journal International, Page 1-12
DOI: 10.9734/BMRJ/2016/13736

Middle ear swabbed samples from patients (aged ≤1 yr to ≥ 60 yrs) attending Ear, Nose and Throat (ENT) clinics at Uyo and Ikot Ekpene with chronic otitis media (COM) were analyzed microbiologically. The occurrences of DNase, β-lactamase, haemolysin production and susceptibility of the isolates obtained to antibiotics were determined using standard techniques. Staphylococcus aureus 65 (24.7%), Pseudomonas aeruginosa 53 (20.1%). Proteus mirabilis 22 (8.4%), Streptococcus pneumoniae 21 (7.9%), coagulase negative Staphylococcus spp 19 (7.2%), Klebsiella pneumoniae 18(6.8%), Escherichia coli 17 (6.5%), Proteus vulgaris 10 (3.8%), Serratia marcescens 9 (3.4%), Streptococcus pyogenes 10 (3.8%), Enterobacter spp 8 (3.0%), Morgenella morganii 7 (2.7%), and Bacillus substilis 4 (1.5%) were obtained. Fungal isolated were 29.2% Aspergillus niger, 6.3% Aspergillus flavus, 22.9% were Candida albicans, 10.4% Candida spp, 17.7% Cryptococcus neoformans and 13.5% Fusarium spp. S. aureus and B. substilis had the highest and lowest frequency of occurrences in both sexes, respectively. Of 31 isolates that showed positivity for β haemolysis, 7 (70.0%) were S. pyogenes and 15 (23.1%) from S. aureus. S. aureus was the highest DNase producers, followed by S. pyogenes 4 (40.0%) and CoN Staphylococcus spp. 1 (5.3%). β-lactamase detection ranged from 28.6% in M. morganii to 55.6% in S. marcescens. Haemolysin and DNase producing C. albicans and other Candida spp were isolated. Between 55.9% and 60.8% isolates were sensitive to ceftriaxone, cefotaxime and ceftazidime, while between 44.4% to 62.5% of Enterobacter spp and S marcescens were resistant to penicillin and ceftazidime. Of the 243 MDR bacteria, 136 (56.0%) were resistant to 4-8 antibiotics with indices ranging from 0.17 to 0.67. C. albicans and A. niger were more sensitive to nystatin than other fungal spp, while between 30.2% to 39.6% of the fungi were resistant to fluconazole and ketoconazole. Conclusively, this study showed the need to find compounds that potentiate antimicrobial activity against multidrug resistant organisms especially those associated with chronic otitis media.

Open Access Original Research Article

Differential Expression Pattern of Heat Shock Protein Genes in Toxigenic and Atoxigenic Isolate of Aspergillus flavus

Raman Thakur, Shraddha Tiwari, Jata Shankar

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/BMRJ/2016/25368

Aflatoxin biosynthesis in Aspergillus flavus requires coordinated expression of regulatory and structural genes. Aflatoxin production is optimum at 24-30°C and inhibition occurs at temperature higher than 35°C. Chaperones or heat-sock proteins are involved in processing of cellular protein and heat-stress induced protein, hence, we studied the genes encoding for heat-shock proteins under the influence of temperature (30°C vs. 37°C). A. flavus isolates, aflatoxigenic (MTCC9367) and atoxigenic (MTCC11580) were grown in glucose minimal salt broth for 24 hours for expression profile of selected genes using quantitative real-time PCR. We monitored the expression profile of genes encoding for heat-shock proteins (hsp98, hsp90, hsp70 and hsp60) and regulatory gene of aflatoxin biosynthesis pathway aflR. We found the similar trend for heat-shock proteins gene expression except hsp70 in aflatoxigenic and atoxigenic isolates of A. flavus. Expression for hsp70 was found to be upregulated at 30°C (vs 37°C)in atoxigenic isolate (P<0.001) of A. flavus in comparison of toxigenic (P<0.05) isolate. Since, heat-shock proteins are involved in protein folding and conformational stability of cellular proteins to maintain the biological activity, our data on transcripts encoding for heat-shock proteins suggested it may influence the aflatoxin biosynthesis process in A. flavus.

Open Access Original Research Article

In-vitro Antifungal Activities of Cola nitida Schott & Endl. (Sterculiaceae) against Five Candida species and Four Dermatophytes

B. A. Adeniyi, O. O. Mebude, T. O. Lawal, K. E. Nwanekwu

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/BMRJ/2016/25066

Aims: Various medicinal and pharmacological values have been observed in species of Cola including their use to treat mouth infections, whooping cough and ringworms. Some studies have been done on their antibacterial and anti-mycobacterial but little or none on antifungal potential. This study was designed to study the antifungal activities of crude extract of Cola nitida against five Candida species and four dermatophytes implicated in various oral and skin infections in vitro.

Place and Duration of Study: Department of Pharmaceutical Microbiology, University of Ibadan, Ibadan, Nigeria, during March 2007 to July 2011.

Methodology: Preliminary phytochemical screening was done using standard conventional methods. Antifungal activity was carried out using the agar cup diffusion technique at 2.0 mg/mL while the minimum inhibitory concentration (MIC) was carried out using the agar dilution method. The kill kinetics study was done using viable counting technique.

Results: The methanol extracts of Cola nitida leaf and Cola nitida seed exhibited significant inhibitory actions against all the 9 pathogens with the formal more effective than the later. Both the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of the plant extract ranged from 0.0625 to 1.00 mg/mL. The antifungal activity of Cola nitida compares favorably well with the control ketoconazole. Phytochemical analyses reveal the presence of tannin, saponin and alkaloids, although at varying degrees. Kill kinetics reveals a concentration dependent decline in the microbial load of the tested organisms with time. The rate of decline increased with increase in concentration.

Conclusion: Current study supports the ethno-medicinal uses of the plants as potential antifungal agents.