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

Abstract

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.