Introduction
Urinary tract infections (UTIs) in pregnancy is classified as Symptomatic bacteriuria & Asymptomatic bacteriuria (ASB) based on clinical presentation. Asymptomatic bacteriuria (ASB) is a condition in which presence of minimum 105 Colony forming units (CFU) per ml of clean catch midstream urine without symptoms and signs such as dysuria, frequency of micturition, fever, loin pains, renal angle tenderness, suprapubic pain and tenderness.1,2 The most common aetiological agent associated with both Symptomatic bacteriuria & Asymptomatic bacteriuria is Escherichia coli 3 which accounts for 70-80% of the isolates. In Pregnancy various physiological and anatomical changes leads to significant alterations in the Urinary tract. These changes have a profound impact on the acquisition of bacteriuria.4 The risk of UTI may begin in 6th week and will be at peak during 22-24th weeks of pregnancy. ASB accounts for 2-11% in Pregnant women.5 Among them 20-50% can develop acute Pyelonephritis6,7 and it can lead to adverse obstetric outcomes as well, such as anaemia, hypertensive disease, prematurity, and higher foetal mortality rates if left untreated. Screening for asymptomatic bacteriuria has become a part of standard obstetric care these days and urine culturing is the Gold Standard screening technique for detecting the ASB which occurs during pregnancy. Failure to detect ASB causes increased risk for Mother and fetus.
Maternal complications include Pyeionephritis, Preeclampsia, endometritis, premature rupture of amniotic membrane, preterm labour and septicemia8 Fetal complications includes abortion, low birth weight(LBW), Intra uterine growth retardation (IUGR) and even foetal death.9,10,11,12,13,7 To ensure proper therapy, adequate knowledge of microorganisms that causes UTI and their Anti microbial susceptibility testing is required.
Aim and Objectives
To study the prevalence, pathogens associated and distribution of ASB with respect to age among antenatal mothers.
To determine the antibiotic sensitivity pattern for the isolated pathogens.
To emphasis the importance of early detection and to give guidance for the treatment and prevention of bacteruria in pregnant patients thereby aiding in the prevention of further complications.
Materials and Methods
This study will be conducted in Department of Microbiology and Obstetrics in a Tertiary Care Hospital. Ethical committee clearance was obtained from the Instituition and informed written consent was obtained from the antenatal mothers before collecting the specimen.
Sample collection
Before collecting urine sample the patients will be instructed to wash their hands and clean their genital area with soap and water and dry the area with sterile gauze pad.
Patients will then be asked to collect 10-20ml of Clean Catch Midstream Urine (CCMSU) in a sterile container and transport it immediately to the microbiological laboratory14,15
Processing of sample
All the collected urine samples will be microscopically examined for the presence of bacteria, RBC and pus cells by Gram stain and wet mount. Then they will be inoculated on to Cysteine Lactose Electrolyte Deficient agar and Blood agar plates and the plates will be incubated at 37 degree C for 18 to 24hrs. Subsequently semi quantitative analysis will be done. A colony count of 105 or more pure isolates will be processed for further identification. The isolates will be identified by standard biochemical tests.15
Table 1
| Culture | No.of samples | Percentage |
| Significant bacteriuria | 12 | 5% |
| Contamination | 5 | 2.1% |
| Sterile | 223 | 92.9% |
Urine culture results (n=240)
Table 2
| AGE(years) | Culture positive samples | Percentage |
| 20-25 | 4 | 33.33% |
| 25-30 | 7 | 58.33% |
| 30-35 | 1 | 8.33% |
Prevalence of Culture positive samples according to age (n=12)
Table 3
| Trimester | Culture Positive Samples | Percentage |
| First | 2 | 16.67% |
| Second | 9 | 75% |
| Third | 1 | 8.33% |
Prevalence of culture positive samples according to trimesters of pregnancy (n=12)
Table 4
Bacterial isolates Detected (n=12)
Table 5
Antimicrobial sensitivity pattern of the Isolates
Antibiotic sensitivity test
The isolates are further tested for antibiotic sensitivity. Antimicrobial sensitivity testing (AST) will be carried out by using modified Kirby Bauer disc diffusion method.
The results will be interpreted in accordance with clinical laboratory standards institute's guidelines (CLSI- 2017).16
Results
Out of 240 urine samples, 12(5%) showed significant bacteriuria. Prevalence of culture positivity with respect to age was maximum between the age group of 25-30 (58.33%). Prevalence of culture positivity among the trimester s of pregnancy was high in the second trimester (75%). Among the bacteria isolated, Escherichia coli was the most (41.67%) followed by klebsiella pneumonia (25%) and CoNS (16.67%). Most of the isolates showed resistance to cephalexin.
Discussion
T he prevalence of Asymptomatic bacteriuria (ASB) in this study was found to be 5%, this correlates with some other studies, which have shown the prevalence between 5 and 12%.17,18,19,20 Various reports across the world have documented a prevalence of as high as 40 to 45%10,6 In this study higher incidence of ASB was reported in 2nd trimester. This correlates with studies done by.21 The common pathogen isolated was Escherichia coli followed by Klebsiella species. This correlates with other studies done by.22,10,19,23,24,25,26,27 The most preferred antibiotics for ASB are Amoxicillin, Cephalexin, Amoxy-clav, Ceftriaxone and nitrofurantoin. But it is advised that nitrofurantoin should not be given after 36 weeks of pregnancy. Antimicrobial susceptibility testing showed , Cephalexin was resistance in most of the isolates and 100% sensitivity towards Nitrofurantoin was seen in most of the isolates. Among the CoNS, one of the isolate was Methicillin Resistant but showed sensitivity to Nitrofurantoin. All the antibiotics should be given for seven days to ensure complete cure.28 Urine culture should be repeated after completion of treatment to ensure complete eradication of pathogen.29,30,31
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