Antibiotics Susceptibility Pattern of Uropathogenic Bacterial Isolates from Community- and Hospital- Acquired Urinary Tract Infections in a Nigerian Tertiary Hospital
S NWADIOHA, E NWOKEDI, G JOMBO, E KASHIBU, O ALAO
antibiotics susceptibility pattern, urinary tract infection, uropathogens
S NWADIOHA, E NWOKEDI, G JOMBO, E KASHIBU, O ALAO. Antibiotics Susceptibility Pattern of Uropathogenic Bacterial Isolates from Community- and Hospital- Acquired Urinary Tract Infections in a Nigerian Tertiary Hospital. The Internet Journal of Infectious Diseases. 2009 Volume 8 Number 1.
The study was designed to determine common bacterial aetiology of community and hospital –acquired urinary tract infection and their antibiotic sensitivity pattern. Reports of urine culture and sensitivity were retrospectively studied from September 2007 to September 2008 in the laboratory of Medical Microbiology and Parasitology Department of Aminu Kano Teaching Hospital, Kano. Results were analysed using SPSS 11.0 statistical software while p- values <0.05 were considered significant. A total of 3500 urine samples were processed .The overall prevalence of urinary tract infection was 26.0% (n=910); community –acquired urinary tract infection was 14.9%(n=520) and hospital-acquired urinary tract infection was 11.1%(n=390). p<.05.
Urinary tract infection (UTI) is the most common health care -associated group of bacterial infection affecting humans in Africa 1. Most of them are as a result of urinary catheter induced infection, which comprises about 85% of nosocomial UTI 2.
A prevalent study done in Nguru, northern Nigeria3, of microorganisms in community –acquired (CA) versus hospital –acquired (HA) UTIs was as follows ,
The present study was therefore carried out to determine the spectrum of bacterial isolates and their antibiotic susceptibility in community versus hospital –acquired UTI in Aminu Kano Teaching Hospital, Kano. The findings underscore the impact of UTI in the locality and the choice of empirical treatment.
Materials and Methods
The study was carried out in Kano, an ancient city situated in north- western part of Nigeria. It is densely populated and known for commercial activities, with a historic background of ground -nut pyramid. The city hosts a teaching hospital named Aminu Kano Teaching Hospital(AKTH) which serves as a referral centre for the state and neigbouring states like Kaduna, Katsina, Jigawa, Yobe.
A retrospective study that reviewed the report of urine microscopy , culture and sensitivity from September 2007 to September 2008 was carried out in Microbiology and Parasitology laboratory of the Aminu Kano Teaching Hospital. The urine samples were collected from out-patient departments and from the wards in the hospital. The samples were grouped into two categories on the basis of community –acquired UTI and hospital acquired UTI.
COMMUNITY –ACQUIRED UTI group, included the following; (1) Out –patients with UTI who visited out-patient clinics. (2) In –patients who had UTI at the time of admission. (3) In-patients who developed UTI less than 24 hours of admission without initial diagnosis of UTI.
HOSPITAL -ACQUIRED UTI group, included the following; (1) In-patients who had been on admission for more than 24 hours but UTI was not diagnosed at the time of admission. (2) Out-patients whose history of UTI was traced from the hospital.
Majority of the samples were midstream urine specimens, and others included catheterized urine samples and supra-pubic aspirates, collected in sterile universal bottles (about 15 ml) and processed immediately or stored at 4 °C within 4 hours. Urine samples were examined macroscopically and microscopically. Uncentrifuged urine was examined under x40 objective for pus cells, red blood cells, casts and crystals and other important features and later centrifuged at 1500 rpm and sediments examined for parasites. The uncentrifuged urine samples were inoculated with a calibrated loop delivering 0.001 ml of urine onto Cystine Lactose Electrolyte Deficient (CLED) agar and Blood agar plates. The culture plates were incubated aerobically at 36 °C for 18 to 24 hours. A number of more than 100 colonies per ml of urine were considered significant. A significant bacteriuria count was taken as any count equal to, or in excess of 10 5 per milliliter of urine. The colonies were identified by standard biochemical tests and antibiotic sensitivity of the organisms was performed by Kirby-Bauer diffusion technique in accordance with NCCLS criteria 7 . Control strains used were
Urine samples belonging to three thousand and five UTI patients were collected and processed between September 2006 to September 2007, in Medical Microbiology and Parasitology laboratory of Aminu Kano Teaching Hospital. Three thousand subjects were managed for community-acquired UTI, while only 500 subjects were managed for hospital acquired UTI .Only nine hundred and ten(26.0%) urine samples yielded uropathogenic bacterial isolates from the patients of UTI in Aminu Kano Teaching Hospital, Kano. Five hundred and twenty bacterial uropathogens were isolated from 3000 urine samples collected from community –acquired UTI patients, whereas, 390(78.0%) isolated from 500 urine samples collected from hospital –acquired UTI patients. These associations were found to be statistically significant.(p<0.05). (Table I).
The sensitivity pattern of bacterial isolates ;
The commonest bacterial organisms in the study were
The degree of resistance to routine antibiotics, by bacterial isolates from hospital-acquired UTI group was significantly higher than that shown by community -acquired UTI group. Such routine antibiotics included Ampicillin, Tetracyclines, Cotrimoxazole, Erythromycin and Chloramphenicol. However, a high sensitivity about 80.0% and above was generally recorded with
Ceftriaxone, Ceftazidime and Ciprofloxacin. The antibiotic sensitivity profile in this study goes a long way to describe the degree of abuse and misuse of common routine antibiotics in our society. In addition, continued exposure of bacteria to routine antibiotics used in the hospital consequently leads to development of resistant strains 10 .
A limitation in the study was differentiating urine samples of patients who were on admission for more than 24 hours from those who were less. In view of this, all urine samples from patients who were on admission for which UTI was not a diagnosis prior to admission were grouped under Hospital –acquired UTI group. The authors are also aware that nosocomial infections can be acquired at the out-patient clinic as well.
We recommend that antibiotic sensitivity reports be obtained before initiation of most antibiotics. The benefits of antibiotics prophylaxis should be thoroughly weighed against the impending resistance to be encountered in the long run .This policy will not only encourage proper treatment of patients with UTI , but would discourage the indiscriminate use of antibiotics and prevent further development of resistant strains among bacteria.
In conclusion, the present study has therefore, shown that the hospital –acquired UTI group of patients has a higher rate of infection. We also observed that the hospital –acquired UTI has a higher risk of antibiotic resistance than the community –acquired UTI. Lastly, floroquinolones(e.g ciprofloxacin) and the third generation cephalosporins(e.g Ceftriaxone, Ceftazidime) should be a reliable choice of antibiotics for empirical treatment of UTI in this locality.