Microbiological study and antibiotic susceptibility pattern among lethargic neonates in Najaf city, Iraq.

The antibiotic susceptibility pattern differs from regions and countries, and physicians must be aware of their specific regions' pattern. Therefore, the recent study aimed to evaluate the microbiological features and the antibiotic susceptibility pattern among neonates admitted into Al-Zahraa teaching hospital, Najaf, Iraq. Materials and Methods: This cross-sectional descriptive study was conducted in the pediatric emergency department and the Neonatal Intensive Care Units (NICUs) of Al-Zahraa teaching hospital in Najaf city, Iraq, for ten months from February 1 to November 1, 2016. Sampling was performed on all lethargic neonates brought to the emergency department and NICUs before they were given any empirical antibiotic therapy. Urine samples were collected using urine bags or suprapubic aspiration in aseptic condition. Positive urine cultures were defined as more than 100,000 CFU/mL bacterial colonies by bag specimen collection and the presence of any colonies regarding suprapubic aspiration. Antimicrobial sensitivity was assessed using the disk diffusion (Kirby-Bauer) method. Results: The most common isolated pathogens were E. coli (45%), followed by Klebsiella spp (25%), Proteus spp (15%). The only gram-positive uropathogen was S. aureus affecting four (10%) neonates. Our study showed the highest overall drug sensitivity to imipenem (97.2%), amikacin (88.89%), and gentamicin (88.89%) and the highest resistance to amoxicillin (91.67%), ampicillin (77.78%), nalidixic acid (77.78%), and nitrofurantoin (77.78%) among gram-negative pathogens. Only one gram-positive pathogen (S. aureus) was detected, affecting four neonates. They were completely sensitive to vancomycin (100%) and linezolid (100%) but resistant to penicillin G (100%). Most E. coli pathogens were resistant to tetracycline (94.44%) and amoxicillin (94.44%), followed by ampicillin and cotrimoxazole (both 88.89%). All the E. coli were sensitive to colistin, imipenem, and meropenem. Discussion: In our study, the most frequent causative organism was E. coli isolates (45%), followed by Klebsiella spp (25%) and Proteus spp (15%). This is in agreement with almost all previous studies with different age groups worldwide. However, in another study conducted by Aljanaby et al. in Najaf governorate, the most frequent causative organism in outpatient adult cases was Klebsiella pneumonia (41.53%). Taheri et al. in Iran showed that most isolates were resistant to ampicillin (95.9%) and gentamicin (52.6%). Although 77.78% of our isolates were resistant to ampicillin, gentamicin accounted for one of the most potent antimicrobial agents (88.89%) against gram-negative organisms, reflecting regional differences. Our finding was consistent with another study conducted in Duhok city, Iraqi Kurdistan, which showed high susceptibility of gram-negative bacteria to aminoglycoside agents and carbapenem.