Biomedical subjects

Amorn Leelarasamee

Publications and source records attributed to Amorn Leelarasamee.

4 recordsLinked to original sources

PubMed2005

Pneumococci: drug susceptibilities and preliminary epidemiological studies by penicillin binding protein genotyping.

A collection of 307 pneumococcal isolates form 84 children and 223 adults admitted to Siriraj Hospital were separated into two groups, penicillin-susceptible (PSSP) and penicillin-nonsusceptible (PNSP). Each group was tested for susceptibilities to 12 drugs (cefuroxime, amoxicillin, chloramphenicol, tetracycline, cefotaxime, ceftriaxone, imipenem, meropenem, ciprofloxacin, ofloxacin, erythromycin and co-trimoxazole). PSSP were susceptible to cefuroxime (87.5%), amoxicillin (100%), chloramphenicol (84.7%), tetracycline (45.8%), cefotaxime (99%), ceftriaxone (99%), imipenem (99%), meropenem (100%), ciprofloxacin (76%), ofloxacin (99%), erythromycin (94.8%) and co-trimoxazole (61.5%). PNSP were resistant to most drugs, except for amoxicillin (99%), ofloxacin (99%) and ciprofloxacin (86.3%). Twenty-two pneumococcal isolates belonging to the three most common serotypes (6, 19, 23) were randomly selected for studies of the pbp2b gene with RFLP. There were 7 distinct pbp2b RFLP patterns. RFLP pattern 1 was the most predominant resistant pattern. The RFLP pattern 2 was found only in PSSP.

Adolescent↗

PubMed2004

Recent development in melioidosis.

PURPOSE OF REVIEW: Burkholderia pseudomallei, the causative agent of melioidosis and a potential biological weapon, is still unfamiliar in some areas where sporadic cases are being reported among travelers. This review highlights findings in 2002-2003 and is an extension of a recent review by Dance. RECENT FINDINGS: The allele profiles of B. pseudomallei are distinguishable from avirulent Burkholderia thailandensis, but Burkholderia mallei is a clone of B. pseudomallei. Capsule and a type III protein secretion apparatus enable B. pseudomallei to survive intracellular killing and facilitate intercellular spread. A strong antibody response to infection is useful for monitoring disease activity. A mutant that is auxotrophic in the branched chain amino acid biosynthetic pathway has been found to be attenuated and protective. A new selective media is useful for isolation from contaminated specimens and the environment. Molecular techniques have been developed to distinguish B. pseudomallei from B. thailandensis and B. mallei as well as for serological diagnosis. Classification of the clinical manifestation is proposed to facilitate global communication, and will be useful to compare the efficacies of new regimens and adjunctive immunomodulatory therapies, such as granulocyte colony-stimulating factor and activated protein C for septicemic melioidosis. SUMMARY: Study of pathogenesis and intracellular survival of B. pseudomallei is advancing and may lead to better methods of therapy and vaccine production. New antimicrobial agents and immunomodulators are being studied to shorten the duration of treatment in the acute and maintenance phases, reduce the high mortality rate in septicemic melioidosis, and prevent relapses.

Bacterial Vaccines↗

PubMed2004

Etiologies of acute undifferentiated febrile illness in Thailand.

BACKGROUND: Acute pyrexia of unknown origin (Acute PUO) was reported to affect approximately 200,000-400,000 patients each year reported by the national Annual Epidemiological Surveillance Report. The patients usually present with fever of less than two-week duration and non-specific symptoms such as malaise, myalgia, headache and loss of appetite. Its mortality rate is less than 0.02 percent. It would be interesting to find the etiologies and propose a management plan if the etiologies are discovered. OBJECTIVE: This prospective epidemiologic study aimed to discover the etiologies of acute undifferentiated febrile illness in a tropical region like Thailand. SUBJECTS AND METHOD: Ten community-based hospitals were chosen as representatives in each part of Thailand to enroll patients into the study. Patients aged over two years old who presented with fever at the participating hospitals during year 1991-1993 were eligible for the study. Entry criteria of acute undifferentiated febrile illnesses (AUFI) included oral temperature over 38.3 degrees C within the last 24 hours, duration of fever ranging from 3-14 days, no specific single organ involvement by history taking and physical examination, normal or non-specific results of the following investigations: complete blood count, thick film for malaria, urinalysis and chest roentgenogram. The patients were hospitalized and a preset diagnostic protocol was performed. Other diagnostic procedures deemed necessary by attending physicians were perform. Patients were followed up within one month after hospital discharge. RESULTS: 1,240 patients were enrolled but only 1,137 case records and results of the serological tests were available for analysis. Etiologies could be found in 471 cases (38.7%). Primary bacteremia was detected in 36 cases (3.2%). E. coli, streptococci, salmonella, Enterobacter spp. and S. aureus were the five most common blood isolates. Serological studies revealed positive results for scrub typhus (7.5%), influenza (6.0%), dengue fever (5.7%), murine typhus (5.3%), enteric fever (1.9%), chikunkunya infection (1.1%), leptospirosis (1.1%) and melioidosis (0.9%). Thirteen cases succumbed (1.1%) in this study. CONCLUSION: The etiologies in the majority (61.3%) of AUFI remained unknown. Rickettsial infection, influenza and dengue fever are the most common identifiable diseases in a tropical country like Thailand especially during the rainy season. A management guideline for diagnosis and treatment of the AUFI with emphasis on primary bacteremia and antimicrobial-treatable AUFI was proposed.

Acute Disease↗

PubMed2004

Bacterial isolation with on-site inoculation of ascites fluid into hemoculture bottle in spontaneous bacterial peritonitis.

OBJECTIVE: To compare the on-site bacterial inoculation of ascites fluid into hemoculture bottle with routine method in the patients who were preliminary diagnosed of SBP. MATERIAL AND METHOD: A retrospective analysis of case records during January-December 2001. RESULTS: A total of 673 specimens from 325 patients were retrieved from the data records at the Department of Microbiology, Siriraj Hospital in 2001. The neutrocytic ascites were found in 163 specimens (94 patients). The routine method and on-site inoculation into the hemoculture bottle were employed in 107 and 56 specimens respectively. Culture-positive neutrocytic ascites was found in the routine method 16 (14.9%) specimens and in the on-site inoculation 26 (46.4%) specimens (p < 0.0001). Among these samples, the two methods were simultaneously performed in 42 specimens of which 18 paired specimens were eligible for analysis. Positive culture was found in 2 samples in which the routine method and in an additional 5 samples in which on-site inoculation into hemoculture bottle method. Using Kappa analysis (e score = 0.328, 95% CI = -0.172 to 0.829) that can be interpreted the on-site inoculation method had a higher yield than the routine technique. Moreover, 21 cases also had their blood and ascites samples simultaneously collected and cultured. 4 of ten (19%) and 5 of eleven (23.8%) cases were found in the routine and on-site and direct inoculation groups respectively. These finding suggested that the severity of infection in among two groups were similar and unlikely to be the cause of the difference of the positive isolation rate in both groups. CONCLUSION: The on-site and direct inoculation of ascites into hemoculture bottle method had a significantly higher isolation rate than routine method (i.e. 46.4% versus 14.9% p < 0.0001) either with separated or paired samples of ascites.

Ascitic Fluid↗