Assessment of environmental factors in expression of heavy metal resistance genes in clinical Pseudomonas aeruginosa isolates associated with urinary tract infections

Abstract Environmental heavy metal pollutants can bio-accumulate; causing co-resistance with antibiotics that are becoming more lethal, susceptible and infectious. This study was aimed to determine the role of environmental factors on the expression of heavy metal resistance genes in clinical Pseudomonas aeruginosa isolates associated with urinary tract infections from Balochistan, Pakistan. 21 samples of water and urine each were collected from different regions of Balochistan. Quantification of heavy metal concentrations was done with atomic absorption spectrophotometry and correlation coefficient of heavy metal concentration in water and urine; pH, TDS and EC was determined in water samples only. Minimum inhibitory concentration (MIC) of heavy metals was found using Kirby-Bauer disk diffusion method. Pseudomonas aeruginosa was inoculated and purified on citramide agar plates from urine. The DNA was isolated by kit method. Polymerase chain reaction was used to determine heavy metal resistance genes (copA, czcA, merA ncc and chrR) using specific primers. The highest concentrations of Cd (0.26±0.018), Zn (0.79±0.002), Cr (0.64±0.009), Cu (0.45±0.016), Co (0.50±0.035) and Ni (0.41±0.021) were found in Harnai, Kalat, Muslim Bagh, Quetta in Khuzdar in Qilla Saifullah respectively in water and urine. However, moderate positive to very strong positive correlation in water vs urine and TDS vs EC concentrations was noted. MIC for Cd, Co, Zn, Cr, Ni and Cu was found at different molar concentration. Molecular identification of P. aeruginosa (926bp) was done with 16SrRNA; Whereas copA, czcA, merA, ncc and chrR genes were also amplified; reflecting an association of heavy metal pollutants and UTIs.