Multi-Drug Resistance Pattern of Lactose Non-Fermenting Escherichia coli as Causative Agent of Urine Tract Infections in Luanda , Angola

This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting Escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Center, Angola. Out of 1170 patient, a total of 120 urine specimens infected with Escherichia coli (>10 CFU/ml) were collected according to the routine protocol of urinalysis. Among these 120 isolates, 25 (21%) isolates were determined as “atypical”, lactose non-fermenting E. colis trains. The twenty-five lactose non-fermenting Escherichia coli strains isolated from urine samples in Luanda Medical Center were declared as Multiple Drugs-Resistant strains with high resistance to Cefalexine (100%), Cefuroxime (100%), Ceftriaxone (92%), Gentamycin (92%), Ciprofloxacin (72%) and Amoxiciclin/Clavulanic (80%). The alarming resistance level to the first-choice drugs for the treatment of urinary tract infections caused by non-fermentative lactose E. coli was observed.


Introduction
The Urinary tract infections (UTIs) are serious health affecting problems worldwide [1] [2].The level of bacterial resistance to antibiotics is growing from year to year and is becoming one of the main problems in the world [3].This is especially true for the developing countries including African continent where DOI: 10.4236/ojmm.2019.91001 2 Open Journal of Medical Microbiology self-medication, overuse and misuse of antibiotics leads to the emergence of multi drug resistant (MDR)bacteria [4] [5].E. coli is the most common and predominated bacteria causing UTIs in human beings.E. coli is facultative anaerobic, Gram-negative bacilli ferments lactose to produce hydrogen sulphide.
Historically been reported that up to 10% of E. coli can be "atypical" non-lactose fermenting.Lactose non-fermenting E. coli has a number of virulence factors and exhibit antibiotic resistance [6].Now there is not a lot of data about lactose non-fermenting E. coli as the etiological agent of urinary tract infection, while the Gram-negative, non-fermenting multi-resistant bacilli make the treatment of these organisms very difficult and expensive [7].According to the Antimicrobial Resistance Global Report of WHO, the data about antibiotic resistance obtained from the African countries is still not enough [1].The aim of this study was conducted to determine the antibiotic resistance pattern of lactose non-fermenting Escherichia coli.

Setting
This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting Escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Center, Angola.

Sampling
Bacteria were isolated according to the routine protocol of urinalysis using MacConkey/CLED HY-Uritest and chromogenic media (Hy-Labs, Israel).The Uritest paddle was dipped into the aseptically collected urine sample and removed immediately.The paddle was transferred into the tube and cap was screwed back loosely, to allow for free transfer of atmosphere.The tube was incubated 18 -24 hours at 37˚C.Test yielding ≥ 10 to blue on CLED agar.The isolated bacteria were then identified by using Gram Stain and their biochemical characteristics using Remelrap ID system kits.

Antimicrobial Susceptibility Testing
Antibiotic susceptibility was determined using the disc diffusion method on

Samples
Between July 2018 and December 2018, 187 positive urine samples from 1170 out-patients were collected at Luanda Medical Center.Out of them, 120 (64%) urine specimens were infected with E. coli (>10 5 CFU/ml).107 (89%) positive sample were belong to females and 13 (11%) were belong to males.Among these 120 isolates, 25 (21%) isolates were determined as atypical, lactose non-fermenting E. coli.The twenty two (88%) lactose non-fermenting E. coli we isolated from female urine samples and 3 (12%) strains were isolated from male samples.The average patient with UTI caused by lactose non-fermenting E. coli were 41 ± 14 years for males and 40 ± 14 for females.

Multi-Drug Resistance
100% of the lactose non-fermenting E. coli isolates were found to be multidrug resistant while 21% lactose fermenting E. coli isolates were MDR.

Discussion
Urine tract infection is one of the most common infections in the world [ E. coli is the most common and predominated causative bacteria in urine tract infections.The level of bacterial resistance to antibiotics is growing from year to year and is becoming one of the main problems in the world [3] [11].Particularly concerned about the increase multidrug resistance level of lactose non-fermenting gram negative rods.The lactose non-fermenting bacilli possess several different Open Journal of Medical Microbiology mechanisms of resistance that makes treatment of these organisms difficult and expensive [6] [7].This is especially true for the developing countries including African continent where improper medication, self-medication, overuse and misuse of antibiotics leads to the emergence of MDR bacteria [4].

Conclusion
Our study has shown the high percentage (21%) presence of the "atypical" lactose

Mueller
Hinton agar according to the Guidelines of the Clinical Laboratory Standards Institute (GCLSI).Different families of antibiotics (discs obtained from OXOID) were used in this study included Cephems; Beta-lactam + inhibitor, Cephalosporines (1st, 2nd and 3rd generations); Fluoquinolones; Tetracyclins; Folate pathway inhibitors; Nitrofurans; Aminoglycosides; Monobactams Open Journal of Medical Microbiology and Carbapenemes.The diameter of the inhibition zone formed around the disc was measured and compared to the critical values of each antibiotic disc (according to CLSI) to qualify the target bacteria as sensitive or resistant.MDR bacteria are defined as resistant to at least three different classes of antibiotics.Multi Resistant strains were according to the Center for Disease prevention and Control [8] [9] [10].
of Medical Microbiology non-fermenting E. coli causing urinary tract infections.The alarming level of multi-drug resistance to the first-choice drugs for the treatment of UTIs caused by lactose non-fermenting E. coli was detected.To our knowledge, this is the first study determined the antibiotic resistance pattern of in UTIs in Angola.