Evaluation of microbial load in oropharyngeal mucosa from tannery workers

Abstract

Background: Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees.

Methods: The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated.

Results: The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid.

Conclusion: Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers.

Keywords: diarrheal diseases; opportunistic microorganisms; oropharyngeal mucosa; respiratory diseases; tannery's working environment.

Fig. 1

Bacteria and yeasts in bucopharinx mucosa samples from tanners. CFU/mL, colony-forming unit per milliliter; T1–T19, participating workers; ++, positive bacteria growth/positive yeast growth; +−, positive bacteria growth/negative yeast growth; −+, negative bacteria growth/positive yeast growth; −−, negative bacteria growth/negative yeast growth.

Fig. 2

Bacteria and yeasts in bucopharinx mucosa samples from workers of the control group. CFU/mL, colony-forming unit per milliliter; C1–C20, participating workers; ++, positive bacteria growth/positive yeast growth; +−, positive bacteria growth/negative yeast growth; −+, negative bacteria growth/positive yeast growth; −−, negative bacteria growth/negative yeast growth.

Fig. 3

Based on macroscopic differentiation, bacteria and yeast are shown, in which can be seen different shapes, sizes, edges, colors, elevation, and surfaces.

Fig. 4

Macroscopic diversity of bacteria and yeast in oropharyngeal mucosa from tanners versus control group.

Fig. 5

Bacterial families identified in oropharyngeal mucosa from the tanners group.

Fig. 6

Antimicrobial susceptibility test of microorganisms identified in tanners. AMC, amoxicillin/clavulanic acid; FLZ, fluconazole; I, intermediate; R, resistant; S, Sensitive; SAM, ampicillin/sulbactam; TIM, ticarcillin/clavulanic acid; TZP, piperacillin/tazobactam.