Associations between socio-environmental determinants and the risk of pulmonary tuberculosis in Guilan, Iran

Background: Certain social determinants may influence host susceptibility to tuberculosis (TB) infections, and increase the risk of developing the disease. Objectives: The present study aimed to evaluate the effects of several host and environmental factors on the risk of TB in northern Iranian households. Patients and Methods: This case control study was conducted for one year between 2010 and 2011 in the Guilan province in Iran. Eightyseven confirmed TB positive cases, based on convenience sampling, were included in this study. A patient positive for TB was confirmed by a positive sputum smear, chest X-ray, and clinical manifestations as diagnosed by a physician. The data were collected using observational methods, and were analyzed by SPSS software. Results: The average mean age of the TB cases was 51±22 years old, and 40.2 (35/87) of the TB cases were male and 59.8 (52/87) were female. The majority of TB cases were from rural areas (71.3, 62/87), while 28.7 (25/87) were from urban areas. Significant differences (P < 0.001) were observed between the geographical conditions and distribution of the disease. The room density of the individuals was significantly different (2.9±1.2 vs. 2.2±1.9, P<0.002) among the TB cases and control group, respectively. A statistical difference was observed between the groups in terms of the building materials (P < 0.05), while significantly inadequate UV irradiation was seen in the houses of the TB patients, compared to the control group (82.8 vs. 14.9,P<0.001). The hygiene of the houses seemed to be a significant risk factor (P<0.001) for TB infection.Conclusions: The results suggest that in the studied region several host and environmental factors were associated with higher risks of TB infection. © 2016, Infectious Diseases and Tropical Medicine Research Center

Antibiotic resistance pattern and distribution of psla gene among biofilm producing pseudomonas aeruginosa isolated from waste water of a burn center

Background: Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa. Objectives: The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran. Materials and Methods: Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates. Results: Biofilm formation was observed in 70 of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9 (n = 15).Conclusions: The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation. � 2015, Ahvaz Jundishapur University of Medical Sciences