Rapid Immunofluorescence Microscopy for Diagnosis of Melioidosis

An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were prospectively compared with the culture results for 776 specimens from patients with suspected melioidosis. The sensitivities of both IF tests were 66%, and the specificities were 99.5 and 99.4%, respectively.     

Simultaneous infection with more than one strain of Burkholderia pseudomallei is uncommon in human melioidosis

A prospective study was performed to determine the rate at which patients with melioidosis are infected with more than one strain of Burkholderia pseudomallei. Genotyping of 2,058 bacterial colonies isolated from 215 samples taken from 133 patients demonstrated that mixed infection is uncommon (2/133 cases [1.5%; 95% confidence interval, 0.2 to 5.3%]).     

Epidemiology and Outcomes Following Open Globe Injury in Agricultural Region,an 11-Year Experience

ABSTRACT

Purpose

To determine the characteristics and epidemiology of open globe injury (OGI) in a third referral centre over 11 years.     

Toxicity of Amphotericin B Deoxycholate-Based Induction Therapy in Patients with HIV-Associated Cryptococcal Meningitis

Amphotericin B deoxycholate (AmBd) is the recommended induction treatment for HIV-associated cryptococcal meningitis (CM). Its use is hampered by toxicities that include electrolyte abnormalities, nephrotoxicity, and anemia. Protocols to minimize toxicity are applied inconsistently. In a clinical trial cohort of AmBd-based CM induction treatment, a standardized protocol of preemptive hydration and electrolyte supplementation was applied. Changes in blood counts, electrolyte levels, and creatinine levels over 14 days were analyzed in relation to the AmBd dose, treatment duration (short course of 5 to 7 days or standard course of 14 days), addition of flucytosine (5FC), and outcome. In the 368 patients studied, the hemoglobin levels dropped by a mean of 1.5 g/dl (95% confidence interval [CI], 1.0 to 1.9 g/dl) following 7 days of AmBd and by a mean of 2.3 g/dl (95% CI, 1.1 to 3.6 g/dl) after 14 days. Serum creatinine levels increased by 37 μmol/liter (95% CI, 30 to 45 μmol/liter) by day 7 and by 49 μmol/liter (95% CI, 35 to 64μmol/liter) by day 14 of AmBd treatment. Overall, 33% of patients developed grade III/IV anemia, 5.6% developed grade III hypokalemia, 9.5% had creatinine levels that exceeded 220 μmol, and 6% discontinued AmBd prematurely. The addition of 5FC was associated with a slight increase in anemia but not neutropenia. Laboratory abnormalities stabilized or reversed during the second week in patients on short-course induction. Grade III/IV anemia (adjusted odds ratio [aOR], 2.2; 95% CI, 1.1 to 4.3; P = 0.028) and nephrotoxicity (aOR, 4.5; 95% CI, 1.8 to 11; P = 0.001) were risk factors for 10-week mortality. In summary, routine intravenous saline hydration and preemptive electrolyte replacement during AmBd-based induction regimens for HIV-associated CM minimized the incidence of hypokalemia and nephrotoxicity. Anemia remained a concerning adverse effect. The addition of flucytosine was not associated with increased neutropenia. Shorter AmBd courses were less toxic, with rapid reversibility.     

Failure of Burkholderia pseudomallei to Grow in an Automated Blood Culture System

We compared the organisms isolated from 30,210 pairs of blood culture bottles by using BacT/Alert system and the conventional system. Overall, 2,575 (8.5%) specimens were culture positive for pathogenic organisms. The sensitivity for detection of pathogenic organisms with the BACT/Alert system (85.6%, 2,203 of 2,575) was significantly higher than that with the conventional method (74.1%, 1,908 of 2,575; P < 0.0001). However, Burkholderia pseudomallei was isolated less often with the BacT/ALERT system (73.5%, 328 of 446) than with the conventional system (90.3%, 403 of 446; P < 0.0001). This finding suggests that use of the conventional culture method in conjunction with the BacT/Alert system may improve the isolation rate for B. pseudomallei in melioidosis-endemic areas.The Gram-negative bacillus Burkholderia pseudomallei is a Tier 1 select agent and the cause of melioidosis.¹ The disease accounts for 20% of all community-acquired septicemias in northeastern Thailand,² where melioidosis is the third most frequent cause of death from infectious diseases.³ Melioidosis is notoriously difficult to cure despite appropriate antimicrobial therapy and has a case-fatality rate of up to 43%.³ More than half of all melioidosis patients are bacteremic, and positive blood cultures for B. pseudomallei obtained at hospital admission and/or during hospitalization are strong prognostic markers for death.⁴Although the automated blood culture system (BacT/Alert) is convenient and currently used in many laboratories in provincial hospitals in Thailand, it is unclear whether its sensitivity for the detection of pathogens is similar to that obtained using a conventional low tech system still commonly used in small hospitals in resource-limited settings.In a retrospective study conducted during January 1, 2009–July 31, 2011 as part of routine patient care at Sappasithiprasong Hospital, a 1,000-bed tertiary-care hospital in northeastern Thailand, we compared the organisms isolated from more than 30,000 pairs of blood culture bottles by using the BacT/Alert system and the conventional system.In conventional system, the culture medium is made in-house, blood culture bottles are incubated in a conventional incubator, and bacterial detection is made by direct visualization with or without regular sub-culture. During the study period, two 5-mL blood samples were regularly obtained from each patient 10–15 minutes apart. The first 5 mL of blood was inoculated into a 40 mL culture media BacT/Alert SA bottle (catalog no. 259789; bioMérieux, Durham, NC). The second 5 mL of blood was inoculated into an in-house bottle containing 40 mL of broth, which consisted of 37 g of brain heart infusion medium broth (catalogue no, 211059; Becton Dickinson, Franklin Lakes, NJ) and 0.25 g of sodium polyanatholesulfonate (catalog no.1000907362; Sigma, St. Louis, MO), in 1 liter of purified water. BacT/Alert bottles were incubated in the BacT/Alert automated blood culture system (bioMérieux) at 35°C for 7 days, and in-house bottles were incubated aerobically in a normal incubator at 35°C for 7 days. Examination of BacT/Alert bottles was done according to the directions provided by the manufacturer, and positive cultures were indicated on the computer screen accompanied by a beeping sound. Positive cultures in the in-house bottles were detected by direct visualization of cloudy broth.Positive bottles from both systems were sub-cultured by using airway needles (bioMérieux) to place approximately 15–20 μL of the culture on chocolate agar, blood agar, and eosin-methylene blue agar. In addition, all in-house bottles were routinely sub-cultured onto blood agar on day 2 of incubation, and all in-house and BacT/Alert bottles were routinely sub-cultured onto blood agar on day 7 of incubation. Blood agar and eosin-methylene blue agar plates were incubated aerobically at 35°C and inspected at 24 hours. Chocolate agar plates were incubated in an atmosphere of 5% CO₂ at 35°C and were inspected at 48 hours. Bacterial or fungal colonies that grew on culture plates were identified by using standard biochemical tests and colonies of presumptive B. pseudomallei were identified by typical colony morphology on Ashdown agar, resistance to gentamicin and colistin, and a positive result for a highly specific latex agglutination test, as described.^5,6A total of 30,210 pairs of blood culture bottles were collected during the study period (10,208, 12,574 and 7,428 in 2009, 2010 and 2011, respectively). Overall, 2,575 (8.5%) specimens were culture positive for pathogenic organisms. A total of 1,536 (59.7%) grew with both methods, 667 (25.9%) grew only with the BacT/Alert system, and 372 (14.4%) grew only with the conventional method.The pathogenic organisms isolated were gram-negative bacteria (68.1%), gram-positive bacteria (20.0%), fungi (9.7%) and polymicrobial organisms (2.2%). The most common pathogens were Escherichia coli (18.9%, 486 of 2,575), B. pseudomallei (17.3%, 446 of 2,575), Klebsiella species (10.3%, 266 of 2,575), Staphylococcus aureus (8.5%, 219 of 2,575), and Pseudomonas spp. (8.0%, 207 of 2,575) (

Silent brain infarcts: A cause of depression in the elderly?

The present study included 1047 elderly participants. At baseline, brain magnetic resonance imaging (MRI) was performed to detect infarcts and white matter lesions; further, depressive disorders were assessed. Participants were followed up during 3.6 years to determine incident and recurrent depression. We found an increased risk of recurrent depression associated with silent brain infarcts.     

Microevolution of Burkholderia pseudomallei during an Acute Infection

We used whole-genome sequencing to evaluate 69 independent colonies of Burkholderia pseudomallei isolated from seven body sites of a patient with acute disseminated melioidosis. Fourteen closely related genotypes were found, providing evidence for the rapid in vivo diversification of B. pseudomallei after inoculation and systemic spread.     

Increasing Incidence of Human Melioidosis in Northeast Thailand

Melioidosis is a serious community-acquired infectious disease caused by the Gram-negative environmental bacterium Burkholderia pseudomallei. A prospective cohort study identified 2,243 patients admitted to Sappasithiprasong Hospital in northeast Thailand with culture-confirmed melioidosis between 1997 and 2006. These data were used to calculate an average incidence rate for the province of 12.7 cases of melioidosis per 100,000 people per year. Incidence increased incrementally from 8.0 (95% confidence interval [CI] = 7.2–10.0) in 2000 to 21.3 (95% CI = 19.2–23.6) in 2006 (P < 0.001; χ² test for trend). Male sex, age ≥ 45 years, and either known or undiagnosed diabetes were independent risk factors for melioidosis. The average mortality rate from melioidosis over the study period was 42.6%. The minimum estimated population mortality rate from melioidosis in 2006 was 8.63 per 100,000 people (95% CI = 7.33–10.11), the third most common cause of death from infectious diseases in northeast Thailand after human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and tuberculosis.