- To disinfect antibiotic resistant bacteria (ARB) present in the waters of Hyderabad City by using different disinfectants.
- To optimize the dose of disinfectants responsible for efﬁcient removal of antibiotic resistant bacteria (ARB) present in the waters of Hyderabad City.
Supervisor Name: Dr. Rasool Bux Mahar, Professor, USPCAS-W, MUET, Jamshoro
Co-Supervisor Name: Dr. Zulﬁqar Merani
The bacteria are natural gift and have strong ability to resist antibiotics. Due to continuous evolving nature of bacteria, they have gained resistance to antibiotics at greater extent. Moreover, the people infected by antibiotic resistant bacteria (ARB) spend much time in hospitals for proper treatment, again using two or three more antibiotics, which can become more toxic, less effective and expensive. The bacteria have acquired the ability to survive under antibiotic treatment by having different antibiotic resistant genes. There are two major reasons for the abundant release of antibiotic resistant bacteria into the aquatic environment i.e. excessive usage of antibiotics and the usage of conventional system for disinfection or absence of disinfection process in water treatment systems. Therefore, antibiotic resistance these days is the major human health challenge for the whole world.
In this study, antibiotic resistant bacteria that were isolated from drinking water sources of Hyderabad city and its surrounding areas were disinfected by using 3 disinfectants namely chlorine, ultraviolet (UV) light and silver nanoparticles. The samples were collected randomly from different drinking water sources including ground water, surface water, tap water, and distribution network. In all, 62 water samples were collected from Hyderabad city and its surrounding areas, and only 14 samples were selected for disinfection process having highest number of heterotrophic plate count. Areas covering Hyderabad city included: Latifabad, Qasimabad and main Hyderabad city whereas, surrounding areas included Jamshoro and Kotri. Disc diffusion method was applied to observe antibiotic resistance pattern of bacteria against commonly used antibiotics in the Hyderabad city. Antibiotic sensitivity and resistivity testing were performed for 62 samples collected in this study. The most common organisms that were isolated in the samples were: Escherichia coli, Pseudomonas aeruginosa, Shigellaspecies and Vibrio species. Antibiotic resistance was checked for 16 antibiotics and out of 16 antibiotics; each sample was seen to resist at least two antibiotics, which means that there was not even a single sample that was completely sensitive to antibiotics used in this study.
Findings of this study showed that all the isolated ARBs were completely disinfected, when chlorine dose of 1.5 mg/L was applied for 30 minutes time period. UV radiations disinfected all the isolated organisms when UV light (11 W, 254 nm and 30, 000 μW/cm2/sec) was applied for the time period of 180 seconds whilesilver nanoparticles (10 nm) showed complete disinfection of the isolated ARBs when their minimum inhibitory concentration (MIC) value reached at 128 μg/mL. All six isolated organisms were disinfected completely by 3 disinfectants i.e. chlorine, UV and silver nanoparticles, which means that their selected doses are likely to have similar impacts on other types of antibiotic resistant bacteria present in the drinking water of Hyderabad city and its surrounding areas.