Molecular and epidemiological characterisation of clinical isolates of carbapenem-resistant Acinetobacter baumannii from public and private sector intensive care units in Karachi, Pakistan.

The purpose of this study was to identify molecular and epidemiological characteristics of hospital-acquired carbapenem-resistant Acinetobacter baumannii (CRAB) from two different intensive care unit (ICU) settings in Karachi, Pakistan. A cross-sectional study was performed in the adult ICUs of a private sector tertiary care hospital (PS-ICU) and of a government sector hospital (GS-ICU) between November 2007 and August 2008. Deduplicated CRAB isolates from clinical specimens were examined for carbapenemase and class 1 integrase genes. Isolates were typed using sequence-based multiplex polymerase chain reaction, pulsed-field gel electrophoresis (PFGE) and variable number tandem repeat (VNTR). A total of 50 patients (33 from PS-ICU and 17 from GS-ICU) were recruited. There were statistically significant differences between patients in the two ICUs in terms of mean age, comorbidities, the presence of central venous pressure lines, urinary catheters, and average length of stay. bla(OxA-23-like) acquired-oxacillinase genes were found in 47/50 isolates. Class 1 integrase genes were found in 50% (25/50) of the organisms. The majority of isolates belonged to strains of European clones I and II. PFGE typing grouped the isolates into eight distinct clusters, three of which were found in both hospitals. Most of the isolates within each PFGE cluster shared identical or highly similar VNTR profiles, suggesting close epidemiological association. Irrespective of differences in risk factors and infection control policies and practices, the extent of clonality among CRAB isolates was very similar in both ICU settings.

Infection control education: impact on ventilator-associated pneumonia rates in a public sector intensive care unit in Pakistan.

We describe efforts towards introducing infection control (IC) practices and establishment of antimicrobial resistance (AMR) surveillance in a public sector hospital in Pakistan. The study was conducted in an eight-bed intensive care unit. IC principles, introduced through interactive sessions, were used as an intervention and their impact was observed by conducting surveillance for ventilator-associated pneumonia (VAP) before and after the intervention. Respiratory isolates of VAP patients in the period after intervention were screened for AMR, and empiric antibiotic at the time of admission was compared with the antimicrobial sensitivity pattern reported. VAP rates were high in general and declined in the period after intervention, although the difference was not significant. Of 37 VAP patients in the period after intervention, 68% had more than one clinically significant organism isolated from the respiratory specimen. Acinetobacter spp. were isolated from 76% of patients and Pseudomonas aeruginosa from 43%. All Acinetobacter spp. and 72% P. aeruginosa were multidrug resistant. The mean stay of the nosocomially infected patients was significantly higher than for the uninfected group (6.5 vs. 2.1 days, P<0.001). Our study suggests IC education needs to be supplemented by a hospital system that facilitates IC practices and development of surveillance programmes.

A novel member of the ligand-gated chloride channel gene family from Haemonchus contortus.

Ligand-gated chloride channels (LGCCs) are key components of the nervous system of parasitic nematodes and important targets for anthelmintics. Here, we describe the isolation and characterization of a novel member of the LGCC gene family (HcLGCC1) from the parasitic nematode Haemonchus contortus. Sequence analysis revealed that the channel subunit encoded by HcLGCC1 is anion selective and a member of a group of channels characterized as having two Cys-loops in the N-terminal ligand-binding domain. Although the overall function of HcLGCC1 is presently unknown, the gene may play a key role in the early developmental stages of the parasite. Further investigations into the function of LGCCs, such as HcLGCC1, in parasitic nematodes should have implications for the discovery of new anthelmintic targets.