Comparison between Pseudomonas aeruginosa siderophores and desferrioxamine for iron acquisition from ferritin

Background: Siderophore is an iron chelator produced by microorganism. Pseudomonas aeruginosa produces two siderophores (pyoverdin and pyochelin). Desferrioxamine is a siderophore used in thalassemia patients to treat an iron overload of vital organs. Objective: Compare the ability of pyoverdin, pyochelin, and desferrioxamine for iron mobilization from ferritin. Materials and Methods: In vitro experiment, the ability of P. aeruginosa siderophores and desferrioxamine for iron mobilization from ferritin was compared by using a dialysis membrane assay at pH values of 7.4 and 6.0. Stimulation of P. aeruginosa PAO1 growth by all siderophores was studied in glucose minimum medium. Results: All three compounds were capable of iron mobilization at both pHs. At pH 6.0, the most effectiveness compound was desferrioxamine (31.6%), followed by pyoverdin (21.5%) and pyochelin (13.7%) compared on weight basis, each at 10 μg/mL. At equimolar concentration, their activities were desferrioxamine (38.5±1.2%), followed by pyoverdin (32.0±4.8%) and pyochelin (26.7±1.9%), respectively. Conclusion: The most effective compound in iron mobilization from ferritin was desferrioxamine, followed by pyoverdin and pyochelin respectively.

Problems and obstacles in implementation of nosocomial infection control in Thailand.

OBJECTIVES: To study the problems in implementation of nosocomial infection (NI) control in Thailand and strategies to overcome the obstacles. MATERIAL AND METHOD: Interviewing administrators, chair-persons of infection control committee and doctors. RESULTS: During June 2002 and August 2003, 255 persons were interviewed by infection control nurses using a set of questionnaires. Administrators, chair-persons of infection control committee, doctors in 32 hospitals across the country were enrolled by stratified random sampling. Policy on NI control was known to 95.3% and implementation to 81.2% of subjects. The main obstacles of NI control was the lack of incentive (66.7%) and support from administrators (30.2%). Hospital administrators set NI control at high priority, in only 40.9%, they could be motivated by regular presentation of NI data. Infection control nurses (ICN) should ideally work full-time (88.6%) but in reality, only 20.8% did so. The main problem for NI control was the shortage of ICN posts in most hospitals. This resulted in no career ladder and incentive for ICN. To overcome these problems, support from administrators, more education programs in NI control and provision of posts for ICN, are needed. CONCLUSION: The main problems and obstacles an implementation of NI control were the lack of support from administrators and the lack of the ICN post.

Development of national guidelines for the prevention and control of nosocomial infections.

OBJECTIVE: To develop a national evidence-based guidelines for the prevention and control of nosocomial infection. MATERIAL AND METHOD: Draft guidelines for the prevention and control of nosocomial infection were developed by the researchers and reviewed by a 10 member panel of experts. The guidelines were modified by brainstorming of 55 practitioners in July 2002. The guidelines were tested for their applicability in 20 hospitals across the country in 2002. The participants gave suggestions on the guidelines which were modified accordingly. The guidelines were finalized by brainstorming of the 55 practitioners in August 2003. RESULTS: National guidelines for the prevention and control of nosocomial infections were developed. Twenty-one topics were included. Modifications of the drafted guidelines were made four times according to the opinions of 10 experts, twice by brainstorming of 55 practitioners and by the suggestions of participants from 20 hospitals where they were tested. The practices in hospitals with different facilities were also suggested in the guidelines. CONCLUSION: National guidelines for prevention and control of nosocomial infection were formulated. Their application for use in every hospital and periodic reviews are expected.

Effect of an education program on the prevention of ventilator-associated pneumonia: A multicenter study.

OBJECTIVE: To evaluate the effect of an educational program targeted on modifiable risk factors on ventilator-associated pneumonia (VAP) rates. MATERIAL AND METHOD: After a preliminary study on VAP risk factors was conducted at one teaching hospital, a pre- and post-interventional study was then performed on 12 hospitals in Thailand from January 1, 2002 to June 30, 2003. Each hospital randomly selected 20 patients, who were on mechanical ventilation to be enrolled The study was divided into two phases; 1) pre-intervention, 2) post-intervention. Data collected included patients 'demography and risk factors for VAP During pre-interventional phase, data on risk factors for VAP was analyzed and fedback to healthcare providers in the wards by an infection control nurse (ICN) of the individual hospital. An educational programme on the prevention of VAP was introduced by the ICN. Ventilator-associated pneumonia rates and their risk factors were continuously monitored during the post-interventionl phase. RESULTS: Two hundred and forty four patients in the pre-interventional phase and 254 patients in the post-interventional phase were included. There was no significant difference in the demography between these two patient populations. After the intervetion, there was a significant improvement in hand-hygiene practices (p<0.001) among healthcare providers and increased use of sucralfate (p=0.05) for stress ulcer prophylaxis. Ventilation-associated pneumonia rate (40.5% vs. 24%; p<0.001) and crude mortality rate associated with VAP (12.3% vs. 8.7%; p<0.001) were also reduced CONCLUSION: The educational programme targeted on modifiable risk factors for prevention of VAP was effective and should be considered as an intervention to reduce VAP rates in developing countries.

Microbial and heavy metal contamination of treated hospital wastewater in Thailand.

OBJECTIVES: To determine the microbial and heavy metal contamination of treated hospital wastewater MATERIAL AND METHOD: Methods of treating wastewater were acquired by questionnaires. Chlorine concentration, pH, bacteria and parasites in treated wastewater were tested in the individual hospitals. Heavy metal concentrations were measured by atomic absorption spectrophotometry. RESULTS: In 2002, 72 hospitals were included in the present study. The common methods of treating wastewater were activated sludge and oxidation ditch. Bacteria exceeded standard numbers, pathogenic bacteria and parasites were found in two-thirds of the hospitals. Heavy metals, namely lead, chromium and cadmium, in the hospital effluent did not exceed standard concentrations. CONCLUSION: Micro-organisms exceeding standard levels were found in treated wastewater in two-thirds of the hospitals. Lead, chromium and cadmium levels in hospital effluent were in an acceptable range.