Pharmacokinetics of vancomycin in neonates admitted to the neonatology unit at the Jordan University Hospital.

BACKGROUND: Vancomycin is used in neonatal intensive care units to treat nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) or coagulase-negative staphylococci. Current dosing regimens are not adequate, producing trough concentrations below the target range. PATIENTS AND METHODS: 151 neonates who received vancomycin and had vancomycin peak and trough concentration measurements as part of regular therapeutic drug monitoring were utilized. The patients were divided into three groups according to gestational age; less than 28 weeks, 28 to less than 34 weeks and 34 weeks to term. Neonates were given vancomycin doses as per guidelines. The pharmacokinetic parameters, elimination rate constant (K), elimination half-life (t1/2), volume of distribution (VD) and clearance (CL), were calculated. RESULTS: Peak vancomycin concentrations ranged from 9.4 to 52.8 mg/l, while troughs ranged from 0.0 to 16.6 mg/l. One third of the trough concentrations were below 5 mg/l and are thus, subtherapeutic. There were no statistically significant differences between the three groups in regard to elimination rate constant and half-life. However, there was a statistically significant difference in volume of distribution between the three groups (p < 0.05), and in clearance between the first group and the other two (p < 0.05), using Kruskal-Wallis statistical test. CONCLUSIONS: The empirical dosing method used was inadequate in one third of patients. Individualization of vancomycin dosing in the neonatal critical care unit at The Jordan University Hospital seems necessary.

Low intestinal colonization of Escherichia coli clone ST131 producing CTX-M-15 in Jordanian infants.

Over a period of 3 years' study (2012-2014), a total of 518 faecal samples were collected and cultured to isolate Escherichia coli. Of these, 338 (65.3%) E. coli isolates were recovered from infants, and 142/338 (42%) were multidrug-resistant (MDR) to ≥ 3 drug classes using the antimicrobial susceptibility disc diffusion method. A total of 125/142 (88%) of E. coli isolates were extended-spectrum ß-lactamase (ESBL) producers. blaCTX-M-15 types were observed in 80/125 (64%) of the isolates, and 60/80 (75%) were positive for blaCTX-M-15. Out of 338 E. coli isolates, 9 (2.6%) were positive for ST131/O25b clone and each isolate was associated with several plasmids of different sizes (1-21.2 kb). The identities of these nine isolates were confirmed by sequencing for presence of pabB (347 bp) and trpA (427 bp) genes. This study demonstrates low prevalence rate of the highly virulent E. coli ST131 clone producing blaCTX-M-15 in the intestines of Jordanian infants.