Faculty Bibliography

OBJECTIVE AND IMPORTANCE: Although Propionibacterium acnes is a common inhabitant of human skin, it is an uncommon pathogen in postoperative infections. We report three cases of postoperative wound infection/osteomyelitis caused by P. acnes. CLINICAL PRESENTATION: Three patients underwent craniotomy for a supratentorial meningioma and had a dural allograft at the time of closure. The patients presented several weeks after surgery with clinical evidence of a wound infection. INTERVENTION: All patients were diagnosed with P. acnes infection and treated for this pathogen with appropriate antibiotics. The bone flap was removed in two patients. After antibiotic therapy, all patients demonstrated no further evidence of infection. CONCLUSION: To our knowledge, this is the first published report of P. acnes infection in patients with a dural substitute. The source of infection cannot be confidently ascertained; however, two patients had strains of P. acnes from one brand of graft, which were indistinguishable by pulsed field gel electrophoresis typing.

We evaluated the BACTEC MGIT 960 system, which is a fully automated, noninvasive system for the growth and detection of mycobacteria with a capacity to incubate and continuously monitor 960 7-ml culture tubes. We studied 3,330 specimens, 2,210 respiratory and 1,120 nonrespiratory specimens, collected from 2,346 patients treated at six sites. Processed specimens were inoculated into the BACTEC MGIT 960 and BACTEC 460 TB systems, as well as onto Lowenstein-Jensen slants and Middlebrook 7H11/7H11 selective plates. From all culture systems, a total of 362 isolates of mycobacteria were recovered; these were recovered from 353 specimens collected from 247 patients. The greatest number of isolates of mycobacteria (289, or 80% of the 362 isolates) was recovered with the BACTEC MGIT 960, followed by the BACTEC 460 TB (271, or 75%) and solid media (250, or 69%). From all culture systems a total of 132 isolates of Mycobacterium tuberculosis complex were recovered. The greatest number of isolates of M. tuberculosis complex was recovered when liquid medium was combined with conventional solid media; the number recovered with BACTEC 460 TB plus solid media was 128 (97%), that recovered with BACTEC MGIT 960 plus solid media was 121 (92%), that recovered with BACTEC 460 TB was 119 (90%) and that recovered with all solid media combined was 105 (79%). The recovery with BACTEC MGIT 960 alone was 102 (77%). The mean times to detection (TTD) for M. tuberculosis complex were 14.4 days for BACTEC MGIT, 15.2 days for BACTEC 460 TB, and 24.1 days for solid media. The numbers of isolates of Mycobacterium avium complex (MAC) recovered were 172 (100%) for all systems, 147 (85%) for BACTEC MGIT 960, 123 (72%) for BACTEC 460 TB, and 106 (62%) for all solid media combined. The TTD for MAC in each system were 10.0 days for BACTEC MGIT 960, 10.4 days for BACTEC 460 TB, and 25.9 days for solid media. Breakthrough contamination rates (percentages of isolates) for each of the systems were 8.1% for BACTEC MGIT 960, 4.9% for BACTEC 460 TB, and 21.1% for all solid media combined

The transmission of perinatal hepatitis C virus (HCV) infection was studied retrospectively in 62 infants born to 54 HCV- and human immunodeficiency virus (HIV)-coinfected women enrolled in a prospective natural history study of HIV transmission. Infant HCV infection was assessed by nested RNA polymerase chain reaction. The overall rate of vertical HCV transmission was 16.4% (9/62). Most HCV-infected children did not develop antibodies to HCV. The rate of HCV infection was higher among HIV-infected infants (40%) than among HIV-uninfected infants (7.5%; odds ratio, 8.2; P = .009). This difference in transmission was not related to differences in maternal HCV load, as measured by branched DNA assay, or mode of delivery. Why HIV-infected infants of HCV- and HIV-coinfected women have significantly higher rates of perinatal HCV transmission remains to be elucidated. The rate of HCV transmission in HIV-uninfected infants of HCV- and HIV-coinfected women is similar to that reported for infants born to HIV-seronegative mothers

STUDY OBJECTIVE: The purpose of this study was to determine whether the time to detection (TTD) of Mycobacterium tuberculosis in sputum culture correlates with the response to antituberculous treatment in patients with pulmonary tuberculosis. STUDY DESIGN: Twenty-six consecutive patients were studied who had active pulmonary tuberculosis and sufficient sputum cultures and clinical follow-up to allow adequate assessment. RESULTS: Following initiation of antituberculous therapy, 13 patients (group 1, responders) had a complete response to treatment, and the TTD of M tuberculosis using the mycobacterial growth indicator tube increased steadily. The remaining 13 patients (group 2, nonresponders) had persistent evidence of active disease and demonstrated little or no increase in the TTD with treatment unless an additional therapeutic intervention was implemented (surgery, improved compliance with medications, or a change in medications). The presence of HIV infection, intravenous drug use, multidrug resistance, treatment with second-line therapy, extensive radiographic involvement, and cavitary disease were associated with a delayed increase in the TTD. CONCLUSIONS: The TTD was superior to clinical, radiographic, or conventional bacteriologic evaluation in determining treatment outcome. The TTD closely correlates with the overall response to treatment for pulmonary tuberculosis and may represent a useful adjunct to predict outcome in these patients

SETTING: Incident patients with active tuberculosis (TB) resistant to two or more drugs in New York City hospitals in 1992. OBJECTIVE: To examine the New York-wide distribution of Public Health Research Institute (PHRI) strain W of Mycobacterium tuberculosis, an extremely drug-resistant strain identified by a 17-band Southern hybridization pattern using IS6110, during the peak tuberculosis year of 1992. We also compared strain W with other strains frequently observed in New York. DESIGN: Blinded retrospective study of stored M. tuberculosis cultures by restriction fragment length polymorphism (RFLP) DNA fingerprinting, and chart review. RESULTS: We found 112 cultures with the strain W fingerprint and 8 variants in 21 hospitals among incident patients hospitalized in 1992. Almost all isolates were resistant to four first-line drugs and kanamycin. This single strain made up at least 22% of New York City multiple-drug-resistant (MDR) TB in 1992, far more than any other strain. Almost all W-strain cases were acquired immune deficiency syndrome (AIDS) patients. The cluster is the most drug-resistant cluster identified in New York and the largest IS6110 fingerprint cluster identified anywhere to date. CONCLUSION: Because recommended four-drug therapy will not sterilise this very resistant strain, there was a city-wide nosocomial outbreak of W-strain TB in the early 1990s among New York AIDS patients. Other frequently seen strains were either also very resistant, or, surprisingly, pansusceptible. Individual MDR strains can be spread widely in situations where AIDS and TB are both common

Mycobacterium avium-intracellulare complex (MAC) is a ubiquitous environmental microorganism whose pathogenicity ranges from innocuous colonization to disease, in immunocompetent as well as immunocompromised individuals. We sought to determine the clinical significance of MAC in sputum cultures of patients with pulmonary tuberculosis (TB). A retrospective analysis between January 1994 and March 1995 at Bellevue Hospital Center revealed both Mycobacterium tuberculosis and MAC in 35 patients (11% of all patients with TB). Of 27 patients reviewed, 52% were HIV-1 infected (median CD4 + 25 cells per microliter). Radiographic manifestations in patients with TB and MAC were similar to those seen in patients with TB alone. Both mycobacteria were cultured primarily from respiratory sources. M tuberculosis was usually cultured first or concurrent with MAC, and in nearly all cases, both species were recovered within 2 months of each other. Most patients improved clinically, bacteriologically, and radiographically with standard antituberculous therapy, except those with advanced AIDS, multidrug-resistant TB (MDR-TB), or disseminated MAC. We conclude that recovery of MAC in sputum is common in patients with pulmonary TB, regardless of HIV-1 infection, MDR-TB, or other clinical, bacteriologic, or radiographic attributes. MAC cultivation in most of these patients likely represents transient colonization, and in most cases is not clinically significant

We tested isolates of Mycobacterium tuberculosis recovered from 117 patients for their susceptibilities to isoniazid (INH) and rifampin (RIF) by the Centers for Disease Control and Prevention's disk modification of the indirect method of proportions (MOP) test and a three-tube mycobacteria growth indicator tube (MGIT; BBL) antimycobacterial susceptibility test (AST). Sixty-seven of the M. tuberculosis isolates were recovered from Lowenstein-Jensen (BBL) subcultures, and 50 of the isolates were recovered from MGIT cultures of samples from various body sites. For the MGIT AST method, 0.5 ml of test organism suspension was inoculated into an MGIT with 0.1 micrograms of INH per ml, an MGIT with 1.0 micrograms of RIF per ml, and growth control MGIT. The tubes were incubated at 37 degrees C and were examined daily. The MGIT AST results were interpreted as follows: susceptible if the tubes containing INH or RIF did not fluoresce within 2 days of the time that the positive growth control fluoresced and resistant if the tubes containing INH or RIF did fluoresce within 2 days of the time that the positive growth control fluoresced. The mean time fluorescence for the positive growth control was 5.5 days. The two methods were in agreement for 114 of the 117 isolates from patients, while for 3 isolates there were minor discordant results