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Lactobacillus sp. is a low virulence bacterium, which rarely causes infection in immunocompetent individuals and usually is considered a contaminant. Normally this organism is susceptible to β-lactam antibiotics, yet resistant strains have been reported. Here, we report a case of a 60-year-old renal transplant recipient who developed an intra-abdominal abscess which grew a carbapenem-resistant Lactobacillus casei. This is significant since it is the first report of a clinical isolate of Lactobacillus sp. that demonstrated both microbiological and clinical resistance to carbapenem use. Moreover, the probiotic supplement that the patient had taken also grew a similar organism raising the concern of probiotic associated infection in immunocompromised individual.

A commercial assay (AmplifiedMycobacterium tuberculosis Direct Test, Gen Probe) which combines transcription-mediated amplification of target rRNA with amplicon detection by a chemiluminescent DNA probe for the rapid detection ofMycobacterium tuberculosis in sputum was evaluated. The test was applied to consecutively collected, NALC/NaOH processed sputum sediments from two laboratories (H and L), each serving a different population of patients with pulmonary tuberculosis. Results were compared to those of fluorochrome staining and culture. A total of 760 specimens obtained from 246 patients were used for the study. The test was positive in 141 of 144 (98 %) specimens that were fluorochrome-positive and culture-positive forMycobacterium tuberculosis. Fifteen of 31 specimens that were fluorochromenegative, culture-positive were also assay-positive. A total of 312 specimens (100 patients) from laboratory H (prevalence = 10 %) and 448 specimens (146 patients) from laboratory L (prevalence = 34 %) were analyzed. Compared to culture, test sensitivity, specificity, positive predictive and negative predictive values were 65 %, 99 %, 94 % and 97 %, respectively, for laboratory H and 93 %, 99 %, 99 % and 97 %, respectively, for laboratory L. If the results were analyzed on the basis of at least one concordant result between the amplification assay and culture in three sputum samples per patient, then the sensitivity, specificity, positive and negative predictive values for identifying infected patients was 70 %, 99 %, 87 % and 97 %, respectively, for laboratory H, and 100 %, 98 %, 96 % and 100 %, respectively, for laboratory L.

The accuracy of combining latex agglutination with selective media for the identification of methicillin-resistant Staphylococcus aureus (MRSA) was determined. Test strains were identified by latex agglutination on blood agar, the heat-stable thermonuclease test and broth microdilution MICs of oxacillin and included 97 MRSA, 56 methicillin-susceptible Staphylococcus aureus, 52 methicillin resistant, and 49 methicillin-susceptible Staphylococcus species. Isolates were grown on trypticase-soy agar with 5% sheep red blood cells (TSAB), Mueller-Hinton agar (MHA), mannitol-salt agar (MSA), and four media designed for the selective growth of MRSA:TSAB with clindamycin and gentamicin, MHA with oxacillin, MSA with oxacillin, and lipovitellin-salt-mannitol agar (LVSM) with 1 microgram oxacillin disks applied. The mean sensitivity, specificity, and positive predictive value for the combination of latex agglutination with selective media for the identification of MRSA was 96%, 99% and 98% respectively.