Isolation and Antibiotic-Resistant Pattern of Opportunistic Infectious Microbes from the Infected Sites of Oral Cancer Patients Compared to That of Healthy People Oral Microbiota

Introduction: Oral cancer is the third most prominent type of cancer in Bangladesh. During or after oral cancer treatment, immune-compromised cancer patients may be susceptible to an infection by multi-drug-resistant opportunistic microbes. This study aims to identify the prevalent microorganisms from the infected site of oral cancer patients and observe their antibiotic susceptibility pattern. Materials and Methods: Clinical samples were collected from the infected sites of oral cancer patients and healthy people. The swabs collected were placed on nutrient agar slant, then incubated for 24 hours at 37ºC. Bacteria from the slant were inoculated in several selective media (Mannitol Salt Agar Media, KF Streptococcus Agar media, Cetrimide Agar, Eosin Methylene Blue Agar). Several biochemical tests identified opportunistic microorganisms. Finally, the antibiotic susceptibility test was performed by the Kirby Bauer disc diffusion method. Results: The study found that 65.4% of microbes isolated from the patients’ oral cavities were Gram-negative bacteria, and 34.6% were Gram-positive bacteria. Among the patient group isolates (n = 55), the most prevalent organism was Pseudomonas spp. (30;54.54%). Others were Klebsiella spp. (27;49.09%), Staphylococcus spp. (24;43.63%), E. coli (14;25.45%), Streptococcus spp. (14;25.45%), Proteus spp. (12;21.8%) and Enterococcus spp. (6;10.90%). Both Gram-positive and Gram-negative microbes from the patient group have shown high resistance to the commonly used antibiotics. In the control group (n = 50), the most prevalent organism was Staphylococcus spp. (15;30%). Other organisms were Streptococcus spp. (6;12%), Klebsiella spp. (11;22%), E. coli (3;6%), Streptococcus spp. (14;25.45%), Pseudomonas spp. (8;16%). The microbes of the control group showed less resistance to the antibiotics and rather showed sensitivity to them. Conclusion: The study revealed a high prevalence of multi-drug-resistant opportunistic microbes on immune-compromised oral cancer patients compared to microbes isolated from healthy people’s oral cavity.

A Study of Prevalence and Pathogenic Activity of Bacteria in the Air of Dhaka City and Their Antimicrobial Resistance Pattern

Bangladesh composes the most polluted air with Dhaka securing the top position. The purpose of the study is the enumeration of the prevalence of pathogenic bacteria in Dhaka city’s air and their antibiotic susceptibility to the common antibiotics. For the sample collection, different selective media was exposed in air where the highest and lowest CFU was 137 and 1 respectively. Pathogens were screened through Hemolysis, DNase and Coagulase test and identified by 16s rRNA sequencing followed by antibiotic susceptibility test. 16s rRNA sequencing revealed that the organisms were Bacillus altitudinis strain 41KF2bT.28, Bacillus licheniformis strain QMA46-2, Bacillus altitudinis, Bacillus pumilis strain BJ-DEBCR-34, Staphylococcus aureus strain TPS3156, Bacillus sp CO16, Pseudomonas sp strain 96LC22 and Shigella dysenteriae strain ATCC 13313. Shigella dysenteriae, Staphylococcus aureus were 81.81% and 54.54% resistant to the antibiotics. Whole-genome sequencing would help to observe mutations in the traits as changes in hemolytic activity were found during pathogenecity tests.

A Comparative Study of Static Biofilm Formation and Antibiotic Resistant Pattern between Environmental and Clinical Isolate of <i>Pseudomonas aeruginosa</i>

Biofilms are dense bacterial colonies, derived from microbially derived sessile community, networked within a polysaccharide matrix with a distinct architecture that has the attachment potential to both alive and abiotic surfaces. Pseudomonas aeruginosa is a model biofilm forming microorganism associated with remarkable morbidity and mortality rate due to emergence of antibiotic resistant pathogenic bacteria. Moreover, Pseudomonas aeruginosa originating from a biofilm is more resistant to a wide range of antibiotics than the planktonic bacteria. This research was planned to develop a comparative study of the biofilm production between potential, antimicrobial resistance of Pseudomonas aeruginosa isolated from mature environmental biofilm and clinical strain of the same species that did not derive from biofilm. It was observed that the Pseudomonas aeruginosa from environmental isolates were resistant to 15 prominent antibiotics, while clinical strain was comparatively resistant to only few of them. A confirmatory analysis of biofilm formation and antibiotic resistance pattern of these two groups of organisms was checked by 96-well microtiter plate and the disc diffusion method respectively. Finally, the results portrayed that the environmental strains with high drug resistance, potentially formed a considerable amount of biofilm in the period of a week whereas;clinical stains formed a negligible amount of biofilm within the same time frame.