Evaluation of a Rapid Diagnostic Antigen Test Kit Ribotest Mycoplasma® for the Detection of Mycoplasma pneumoniae

PURPOSE: Early detection of Mycoplasma pneumoniae is important for appropriate antimicrobial therapy in children with pneumonia. This study aimed to evaluate the diagnostic value of a rapid antigen test kit in detecting M. pneumoniae from respiratory specimens in children with lower respiratory tract infection (LRTI). METHODS: A total of 215 nasopharyngeal aspirates (NPAs) were selected from a pool of NPAs that had been obtained from children admitted for LRTI from August 2010 to August 2018. The specimens had been tested for M. pneumoniae by culture and stored at −70°C until use. Tests with Ribotest Mycoplasma® were performed and interpreted independently by two investigators who were blinded to the culture results. RESULTS: Among the 215 NPAs, 119 were culture positive for M. pneumoniae and 96 were culture negative. Of the culture-positive specimens, 74 (62.2%) were positive for M. pneumoniae by Ribotest Mycoplasma®, and 92 of the 96 (95.8%) culture-negative specimens were negative for M. pneumoniae by Ribotest Mycoplasma®. When culture was used as the standard test, the sensitivity and specificity of Ribotest Mycoplasma® were 62.2% and 95.8%, respectively. Additionally, the positive predictive value, negative predictive value, and overall agreement rates with Ribotest Mycoplasma® were 94.9%, 67.2%, and 77.2%, respectively. CONCLUSIONS: A positive test result of Ribotest Mycoplasma® suggests a high likelihood of culture-positive M. pneumoniae infection. However, a negative test result should be interpreted with caution because nearly one-third of negative test results reveal culture-positive M. pneumoniae infections.

Changes in the Serotype Distribution among Antibiotic Resistant Carriage Streptococcus pneumoniae Isolates in Children after the Introduction of the Extended-Valency Pneumococcal Conjugate Vaccine

This study investigated the serotype distribution and antimicrobial resistance of 3,820 nasopharyngeal Streptococcus pneumoniae isolates from infants and children who presented with respiratory symptoms at Seoul National University Children's Hospital from July 2010 to June 2015 after the introduction of the extended-valency pneumococcal conjugate vaccines (PCVs). Serotypes and antimicrobial susceptibility were determined using the Quellung reaction and E-test, respectively. S. pneumoniae was isolated from 397 (10.4%) specimens. The most common serotypes were 19A (14.0%), 23A (12.8%), 15B/C (10.7%), 11A (10.1%), 6C (7.8%), and 6A (6.3%) among the typeable pneumococci (n = 335). The PCV serotype proportions significantly decreased (59.1% in 2010/11 to 17.0% in 2014/15, P < 0.001), whereas the non-PCV serotype proportions significantly increased (40.9% in 2010/11 to 83.0% in 2014/15, P < 0.001). The non-susceptibility rates for penicillin (oral), penicillin (parenteral, non-meningitis), cefotaxime, and erythromycin were 97.8%, 22.8%, 27.7%, and 95.5%, respectively. The proportions of PCV serotypes responsible for non-susceptibility to penicillin (parenteral, non-meningitis) and multidrug resistance significantly decreased (80.8% to 21.1%, P < 0.001 and 64.3% to 12.3%, P < 0.001, respectively), whereas the non-PCV serotype proportions significantly increased (19.2% to 78.9%, P < 0.001 and 35.7% to 87.7%, P < 0.001, respectively). Serotypes 23A and 15B/C demonstrated significant proportional increase among the antibiotics resistant strains. Thus, the PCV serotype proportions decreased and the non-PCV serotype proportions increased among nasopharyngeal carriage pneumococci after the introduction of extended-valency PCVs in Korea. Antimicrobial non-susceptibility rates for penicillin and erythromycin remain high despite the decrease in the proportion of PCV serotypes responsible for antimicrobial resistance over time.

Effect of Enflurane Anesthesia on Patients Treated with Isoniazid / 대한마취과학회지

Enflurane is metabolized in the liver by the hepatic microsomal enzyme system, cytochrome P-450 and induces enzyme during the enflurane exposure. Enhanced biotransformation might occur after enflurane itself and several other drugs, isoniazid (INH), ethanol and cholorpromazine. Increased inorganic fluroide, one of the enflurane metaboites, could impair renal function. The possibility of increased enflurane defluorination follwing treatment with isoniazid, isoniazid group (n=10) and control group (n= 11) was investigated by the measuring the serum and urine F in the preoperative period and 2 hrs after anesthesia, immediate postoperative and 24th postoperative hour. According to the serum inorganic fluoride concentration, the isoniazid group was divided again into INH high F- and INH low F- groups. In the preoperative, immediate postoperative period and 24th postoperative hour, the changes of renal function were measured by the BUN and creatinine and liver function was measured by the SGOT and SGPT. The results were as follows: 1) Serum inorganic fluoride increased in enflurane anesthesia significantly in all three groups and decreased in the 24th postoperative hour. Among the three groups, enhanced defluorination was the highest in the INH high F group. 2) Urine inorganic fluoride was increased in the control and INH high F group. 3) There were no changes in renal and hepatic function after enflurane anesthesia. Our study indicated that enflurane does not harm the INH treated patient.