Prevalence and antimicrobial resistance of non-typhoid Solmonella in military personnel,1988-2013

Objective: To describe the spanning 25 years data for the occurrence,magnitude,and trends regarding antimicrobial resistance of non-typhoidal Salmonella(NTS) isolated from non-immune travelers to Thailand participating in joint military operations.Methods: A total of 355 NTS isolates,obtained from 2 052 fecal samples from US soldiers deployed for military maneuvers in Thailand during 1988-2013,were examined for NTS serogroup/serotypes and tested for antimicrobial susceptibility by disk diffusion to these 10 antibiotics:ampicillin,azithromycin(AZM),ciprofloxacin,colistin,gentamicin,kanamycin,nalidixic acid,streptomycin(STR),tetracycline(TET),and trimethoprim/sulfamethoxazole.Identified AZM-resistant NTS isolates were further evaluated for their minimal inhibitory concentration by the E-test method.Results: NTS infections accounted for 17.3%(355/2 052),including11 serogroups and 50 different serotypes.The most prevalent serogroup was Salmonella group C2-C3(35.8%,127/355) followed by groups B(21.1%,75/355) and C1(18.6%,66/355).Identified serotypes included Salmonella hadar(n=60),Salmonella rissen(n=45),and Salmonella blockley(n=34).Among the predominate serogroups,antimicrobial resistance was consistently high against TET(76.9%,273/355) followed by STR(40.8%,145/355).One Salmonella senftenberg isolate demonstrated decreased ciprofloxacin susceptibility.Most isolates(94.6%) were resistant to one or more antimicrobials,and the most common multidrug resistance was TET-STR-nalidixic acid(11.5%,41/355).Conclusions: The prevalence of NTS serotypes and the growing magnitude of antibiotic resistant bacteria isolated from deployed US military in Thailand are documented from 1988-2013.This study demonstrates the antibiotic resistance profiles,highlighting the effectiveness of AZM that is a first-line treatment for travelers to Southeast Asia.AZM-resistant NTS isolates are periodically observed over a 25-year period.Hence,the ongoing surveillance and prevalence efforts are required to monitor NTS resistant strains causing further treatment failure.     

Contribution of gene loss to the pathogenic evolution of Burkholderia pseudomallei and Burkholderia mallei

Burkholderia pseudomallei is the causative agent of melioidosis. Burkholderia thailandensis is a closely related species that can readily utilize l-arabinose as a sole carbon source, whereas B. pseudomallei cannot. We used Tn5-OT182 mutagenesis to isolate an arabinose-negative mutant of B. thailandensis. Sequence analysis of regions flanking the transposon insertion revealed the presence of an arabinose assimilation operon consisting of nine genes. Analysis of the B. pseudomallei chromosome showed a deletion of the operon from this organism. This deletion was detected in all B. pseudomallei and Burkholderia mallei strains investigated. We cloned the B. thailandensis E264 arabinose assimilation operon and introduced the entire operon into the chromosome of B. pseudomallei 406e via homologous recombination. The resultant strain, B. pseudomallei SZ5028, was able to utilize l-arabinose as a sole carbon source. Strain SZ5028 had a significantly higher 50% lethal dose for Syrian hamsters compared to the parent strain 406e. Microarray analysis revealed that a number of genes in a type III secretion system were down-regulated in strain SZ5028 when cells were grown in l-arabinose, suggesting a regulatory role for l-arabinose or a metabolite of l-arabinose. These results suggest that the ability to metabolize l-arabinose reduces the virulence of B. pseudomallei and that the genes encoding arabinose assimilation may be considered antivirulence genes. The increase in virulence associated with the loss of these genes may have provided a selective advantage for B. pseudomallei as these organisms adapted to survival in animal hosts.     

Behavior of Abate in microorganisms isolated from polluted water

Water collected from the Denton sewage lagoon and the Wye Institute farm pond showed some effects on the degradation of Abate. There was some indication of greater radioactivity in the water after extraction, which might indicate hydrolytic metabolism of Abate. Greater amounts of radioactivity in the aqueous fractions after extraction resulted from the sewage lagoon water than the farm pond water. However, there was no difference between the various sources of water in the oxidative metabolism of Abate which would result in metabolites in the organic-solvent extract of the water.The microorganisms used in this study were isolated from the Denton sewage lagoon water. The selective isolate, which is possibly aPseudomonas sp., could break down Abate into water-soluble compounds and convert Abate into highly polar metabolites. However, the metabolites resulting from incubation of Abate with microorganisms, medium-only controls, and distilled water were the same; only the relative amounts of the metabolites were different between a selectively isolated microorganism, a general isolate, and the controls. Abate was found to be the major compound isolated in every test. Some of the metabolites, which have been found in other studies of the metabolism of Abate, were not found in this study, but several other metabolites, which have not been found by others, were present. The medium used in this experiment also showed some effects on the degradation of Abate. The general isolate seemed to have very little effect on Abate.Scientific article No. A2122, Contribution No. 5083, of the Maryland Agricultural Experiment Station, Department of Entomology. Part of a thesis presented by the first author to the Graduate School, University of Maryland, in partial fulfillment of the requirements for the M.S. degree. A contribution to regional project NE-53, Biological Degradation of Agricultural Pesticides.     

Myocardial depression in dengue hemorrhagic fever: prevalence and clinical description.

OBJECTIVES: To determine the prevalence of myocardial depression and its effect on the clinical severity in patients with dengue hemorrhagic fever. DESIGN: Clinical study. SETTING: King Chulalongkorn Memorial Hospital, Bangkok, Thailand. PATIENTS: Ninety-one children (age 10.5 +/- 2.9 yrs, male/female = 52/39) with serologically or polymerase chain reaction-proven dengue virus infection. INTERVENTIONS: Left ventricular ejection fraction (EF) was measured. The proportions of patients with EF <50% were identified in patients with dengue fever (DF, n = 30), dengue hemorrhagic fever without shock (DHF, n = 36), and dengue shock syndrome (DSS, n = 25). Comparisons of clinical findings were made among DSS patients with depressed ventricular function (EF <50%), fair ventricular function (EF > or =50% and <60%), and good ventricular function (EF > or = 60%). Serum troponin T was analyzed in nine patients. MEASUREMENTS AND MAIN RESULTS: EF during toxic stage was significantly lower in patients with DSS than DHF, and lower in DHF than DF (p = .05) with rapid recovery within 24-48 hrs. EF <50% was found in 6.7%, 13.8%, and 36% of patients with DF, DHF, and DSS during the toxic stage, respectively (p = .01). DSS patients with poor ventricular function had significantly more tachycardia and hepatomegaly. While end-diastolic volumes were similarly reduced, patients with lower EF tended to have lower cardiac output, required more aggressive intravenous fluid resuscitation, developed larger pleural effusion, and had higher incidence of respiratory embarrassment. No patient had elevated troponin T level. CONCLUSIONS: Transient myocardial depression is not uncommon in patients with DSS. Cardiac dysfunction in children with DSS may contribute to the clinical severity and the degree of fluid overload in these patients.     

Patients’ perspectives regarding hospital visits in the universal health coverage system of Thailand: a qualitative study

Background

A universal health coverage policy was implemented in Thailand in 2002 and led to an increase in accessibility to, and equity of, healthcare services. The Thai government and academics have focused on the large-scale aspects, including effectiveness and impacts, of universal health coverage over one decade. Here, we aimed to identify patients’ perspectives on hospital visits under universal health coverage.

Methods

A qualitative study was carried out in four public hospitals in rural Thailand. We collected data through focus group discussions (FGDs) and in-depth interviews (IDIs). The semi-structured interview guide was designed to elicit perspectives on hospital visits among participants covered by the Universal Coverage Scheme, Social Security Scheme or Civil Servant Medical Benefit Scheme. Data were transcribed and analysed using a thematic approach.

Results

Twenty-nine participants (mean age, 56.76?±?16.65 years) participated in five FGDs and one IDI. The emerging themes and sub-themes were identified. Factors influencing decisions to visit hospitals were free healthcare services, perception of serious illness, the need for special tests, and continuity of care. Long waiting times were barriers to hospital visits. Employees, who could not leave their work during office hours, could not access some services such as health check-ups. From the viewpoint of participants, public hospitals provided quality and equitable healthcare services. Nevertheless, shared decision making for treatment plans was not common.

Conclusions

The factors and barriers to utilisation of healthcare services provide exploratory data to understand the healthcare-seeking behaviours of patients. Perceptions towards free services under universal health coverage are positive, but participation in decision making is rare. Future studies should focus on finding ways to balance the needs and barriers to hospital visits and to introduce the concept of shared decision making to both doctors and patients.

     

Clinical Potential of a Silk Sericin-Releasing Bioactive Wound Dressing for the Treatment of Split-Thickness Skin Graft Donor Sites

Purpose

An ethyl alcohol-precipitated silk sericin/PVA scaffold that controlled the release of silk sericin was previously developed and applied for the treatment of full-thickness wounds in rats and demonstrated efficient healing. In this study, we aimed to further evaluate the clinical potential of this scaffold, hereafter called “silk sericin-releasing wound dressing”, for the treatment of split-thickness skin graft donor sites by comparison with the clinically available wound dressing known as “Bactigras®”.

Methods

In vitro characterization and in vivo evaluation for safety of the wound dressings were performed. A clinical trial of the wound dressings was conducted according to standard protocols.

Results

The sericin released from the wound dressing was not toxic to HaCat human keratinocytes. A peel test indicated that the silk sericin-releasing wound dressing was less adhesive than Bactigras®, potentially reducing trauma and the risk of repeated injury upon removal. There was no evidence of skin irritation upon treatment with either wound dressing. When tested in patients with split-thickness skin graft donor sites, the wounds treated with the silk sericin-releasing wound dressing exhibited complete healing at 12?±?5.0 days, whereas those treated with Bactigras® were completely healed at 14?±?5.2 days (p?=?1.99?×?10^?4). In addition, treatment with the silk sericin-releasing wound dressing significantly reduced pain compared with Bactigras® particularly during the first 4 postoperative days (p?=?2.70?×?10^?5 on day 1).

Conclusion

We introduce this novel silk sericin-releasing wound dressing as an alternative treatment for split-thickness skin graft donor sites.     

Case-Control Study of Diarrheal Disease Etiology in a Remote Rural Area in Western Thailand

The objective was to assess the association of enteric pathogens in diarrheal disease in a remote rural area in Thailand. Stool specimens were collected from 236 children aged 3 months to 5 years with acute diarrhea (cases) and from 236 asymptomatic controls. Standard microbiologic methods, and enzyme immunoassay for viral pathogens, Giardia, and Cryptosporidium, were used to identify enteric pathogens with susceptibility testing by disk diffusion. Campylobacter, Plesiomonas, Salmonella, and enterotoxigenic Escherichia coli were commonly isolated from cases and controls (22% versus 25%, 10% versus 11%, 6% versus 9%, and 10% versus 6%, respectively). Only Shigella, rotavirus, and adenovirus were identified significantly more frequently in cases than controls (9% versus 0%, 18% versus 3%, and 16% versus 2%, respectively), whereas Giardia lamblia was detected less often in cases than controls. Most pre-school children were infested with enteric pathogens; laboratory-based studies are important to understand the epidemiology of enteric pathogens in remote areas among marginal populations.     

Intestinal parasitic infections among pre-school children in Sangkhlaburi, Thailand

This study was conducted to investigate the presence of intestinal parasites among pre-school children (aged 3 months to 5 years) in Sangkhlaburi, a rural district in the west of Thailand along the Thai-Myanmar border. Stool specimens were collected from October 2001 through October 2002. A total of 472 pre-school children, 233 males and 239 females, 236 children with diarrhea and 236 asymptomatic children were recruited for the study. Each specimen was processed and examined by direct wet smear, modified acid fast stain, formalin-ethylacetate sedimentation concentration technique, and trichrome stain. In detecting Giardia lamblia and Cryptosporidium species ProSpecT Microplate assays (Alexon-Trend, Lenexa, KS) were performed. There were 107 individuals (22.7%), 41 diarrheal and 66 asymptomatic children, infected with intestinal parasites. The most frequent parasites identified in cases and controls were G. lamblia and Cryptosporidium spp. Eighteen specimens (3.8%) showed mixed parasite infections. Highest proportion of intestinal parasites occurred during the rainy season (June-October).