Scedosporium prolificans keratouveitis in association with a contact lens retained intraocularly over a long term.

Scedosporium prolificans is a soil saprophyte that is associated with a large variety of infectious processes and with respiratory colonization in immunocompetent and immunocompromised patients. We report the first described case of S. prolificans keratouveitis associated with the intraocular long-term retention of a contact lens in a 76-year-old female patient.

Emergence of resistance to clarithromycin during treatment of disseminated cutaneous Mycobacterium chelonae infection: case report and literature review.

Results of in vitro susceptibility studies and one clinical trial have led to recommendations of clarithromycin monotherapy for the treatment of disseminated cutaneous Mycobacterium chelonae infections. We describe the case of a 65-year-old woman, immunocompromised by the use of chronic steroid therapy, who developed disseminated cutaneous infection with M. chelonae and failed clarithromycin monotherapy due to the development of drug resistance. In the relapse isolate we document the presence of a single point mutation at position 2058 in the gene coding for 23S rRNA peptidyltransferase regions, a mutation previously implicated in the development of resistance to clarithromycin. Two susceptible control isolates lacked the mutation. Three additional reports in the literature of patients developing recurrent skin lesions with clarithromycin-resistant M. chelonae following initial response to monotherapy are summarized. We demonstrate that clarithromycin monotherapy in patients with disseminated cutaneous infections can lead to clarithromycin resistance and therapeutic failure associated with a single point mutation at position 2058 of 23S rRNA.

Disinfection of eyelid specula with chlorhexidine gluconate (Hibiclens) after examinations for retinopathy of prematurity.

BACKGROUND: The preferred method of cleaning eyelid specula between examinations for retinopathy of prematurity is unknown. A previous study showed that disinfection with 70% isopropyl alcohol swabs fails to eliminate viruses and bacteria from the specula. OBJECTIVE: To determine if alternative sterilization procedures would allow multiple use of a single speculum without risking nosocomial infection. METHODS: In phase 1, 40 autoclave-sterilized eyelid specula were randomized into either "cleaned" or "patient control" groups after being used for routine retinopathy of prematurity examinations performed in the outpatient setting. Specula in the cleaned group were cleaned with chlorhexidine gluconate (Hibiclens). Specula in the patient control group were not cleaned after use. All study specula were placed into enriched culture media from which bacterial and fungal cultures were obtained. In phase 2, 20 autoclave-sterilized eyelid specula were inoculated with a clinically relevant dilution of adenovirus serovar 5 or herpes simplex type 2. Specula were randomized into either a cleaned or a control group, and cell cultures and immunofluorescence assays were used to document and confirm, respectively, viral growth. RESULTS: In phase 1, all 20 cultures from the patient control group grew bacteria compared with 0 (0%) of 20 cultures from the cleaned group and 0 (0%) of 5 from the cleaned control group. No fungi were isolated from any group. In phase 2, all 10 cultures from specula inoculated with adenovirus serovar 5 grew virus. None of the cultures from the 5 cleaned specula inoculated with herpes simplex type 2 grew virus. In contrast, all 5 cultures in the control group were positive for growth of herpes simplex type 2. CONCLUSIONS: Autoclave sterilization is the ideal method of sterilization of eyelid specula between neonate examinations. When an alternative disinfection technique is required, washing the speculum with chlorhexidine gluconate and tap water is preferred over wiping with a 70% isopropyl alcohol swab. Arch Ophthalmol. 2000;118:786-789

Sterilization of talc for pleurodesis. Available techniques, efficacy, and cost analysis.

Although talc has been used as a pleurodesis agent since 1935, a sterilization protocol has not been established. We obtained USP asbestos-free talc from six different suppliers and sterilized each using dry heat, gamma irradiation, and ethylene oxide gas. Aerobic, anaerobic, and fungal cultures were obtained prior to sterilization, and 1, 30, and 90 days after sterilization. Bacillus species were cultured from all six unsterilized specimens and coagulase-negative Staphylococcus grew from two unsterilized specimens. No growth of organisms was found following any method of sterilization. The cost of sterilization per 5-g packet of talc was $4.74, $7.85, and $16.25 for heat, ethylene oxide, and gamma irradiation, respectively. In conclusion, untreated talc is not sterile. Sterilization by prolonged dry heat exposure, ethylene oxide gas, and gamma irradiation are all effective, with dry heat being the least expensive.

Identification of influenza A virus by shell vial culture and two commercially available antigen detection methods.

BACKGROUND: Effective use of amantidine and rimantidine for treating patients and for reducing transmission requires rapid diagnosis of influenza A. Rapid culture methods require 1-2 days to detect influenza A virus. Direct fluorescent antibody (DFA) staining and enzyme immunoassay (EIA) can detect influenza A antigen within 1-4 h. OBJECTIVES: We compared DFA staining using the Bartels viral respiratory panel and the Directigen FLU-A EIA with shell vial centrifugation culture. STUDY DESIGN: Ninety-seven fresh specimens from a variety of respiratory sources and transported from hospitals throughout the USA to our national referral laboratory were tested. A true positive was defined as culture positive or both antigen tests positive. RESULTS: Fifteen specimens were true positive. Sensitivity with culture was 93%, EIA 67%, and DFA 47%. Specificity was excellent with all three methods: 100%, 98%, 99%. Culture detected additional viruses that can cause respiratory tract disease: herpes simplex, cytomegalovirus, respiratory syncytial, influenza B, and adenovirus. Fourteen (70%) of 20 frozen specimens previously positive for influenza A were positive on retest by EIA. Overall sensitivity of EIA compared with culture using 35 positive specimens was 69%. CONCLUSIONS: These results suggest that the rapid EIA is useful to screen for influenza A, but that critical antigen-negative specimens should be submitted to a virology laboratory for culture for optimal sensitivity and for recovery of other viruses.

Identification of influenza A virus by shell vial culture and two commercially available antigen detection methods.

BACKGROUND: Influenza continues to be a major cause of morbidity and mortality especially in the elderly and persons with underlying disease. Shell vial cell culture and antigen detection techniques may speed up diagnosis and enable better patient treatment and management. OBJECTIVES: To compare shell vial centrifugation culture with commercially available direct fluorescence and enzyme immunoassay kits using a variety of respiratory specimens. STUDY DESIGN: To detect influenza A virus, we compared direct fluorescent antibody (DFA) staining using the Bartels Viral Respiratory Panel and the Directigen FLU-A enzyme immunoassay (EIA) with shell vial centrifugation culture. Ninety-seven fresh specimens from a variety of respiratory sources, and transported from hospitals throughout the U.S. to our national referral laboratory, were tested. RESULTS: Fifteen specimens were true positives: culture positive or both antigen tests positive. Sensitivity with culture was 93%, EIA 67%, and DFA 47%. Specificity was excellent with all three methods: 100%, 98%, 99%. Culture detected additional viruses that can cause respiratory tract disease: herpes simplex, cytomegalovirus, respiratory syncytial, influenza B, and adenovirus. Fourteen (70%) of 20 frozen specimens previously positive for influenza A were positive on retest by EIA. Overall sensitivity of EIA compared with culture using 35 positive specimens was 69%. CONCLUSIONS: The rapid EIA is useful to screen for influenza A, but critical antigen-negative specimens should be submitted to a virology laboratory for culture. Shell vial cultures can provide a sensitive and universal diagnostic system for influenza A and a variety of other viruses.

Rapid detection of Streptococcus pyogenes in pediatric patient specimens by DNA probe.

A chemiluminescent DNA probe test (Group A Streptococcus Direct Test; Gen-Probe, Inc., San Diego, Calif.) for rapid, direct detection of cRNA of Streptococcus pyogenes in throat swabs was compared with conventional culture and identification techniques. Throat swabs from 277 patients suspected of having streptococcal pharyngitis were examined. By DNA probe alone, 10 specimens were positive, 51 were positive by both assays, and 8 were positive by culture alone. Thus, DNA probe sensitivity, specificity, and positive and negative predictive values were 86, 95, 84, and 96%, respectively. Including an indeterminate category, sensitivity, specificity, and positive and negative predictive values were 89, 96, 86, and 97%, respectively. After discrepancy testing, these values for the raw data improved to 90, 98, 93, and 97%, respectively. None of the 24 specimens that grew non-S. pyogenes beta-hemolytic streptococci in culture were positive by the DNA probe. Because mucoid S. pyogenes strains are more virulent than nonmucoid strains, 24 isolates were retrospectively tested with the DNA probe to ensure that both types would be detected equally well. Isolates were examined in pure cultures as well as mixed with representative normal oral flora. There was no statistical difference in detection of any of the four groups. Group A Streptococcus Direct Test is a rapid, sensitive, and specific test for S. pyogenes.

Bordetella pertussis induces respiratory burst activity in human polymorphonuclear leukocytes.

Virulent Bordetella pertussis strains survive intracellularly within human polymorphonuclear leukocytes (PMN), at least in part because of inhibition of phagosome-lysosome fusion (L. L. Steed, M. Setareh, and R. L. Friedman, J. Leukocyte Biol. 50:321-330, 1991). Further investigations were done to determine if B. pertussis also inhibited respiratory burst activity of PMN as an additional mechanism of intracellular survival. Chemiluminescence and flow cytometry assays showed that B. pertussis induced significant levels of hydrogen peroxide production. In contrast, ferricytochrome c reduction showed that B. pertussis suppressed extracellular release of superoxide. PMN intracellular reduction of nitroblue tetrazolium verified that superoxide was indeed produced intracellularly during B. pertussis phagocytosis. Therefore, B. pertussis does not inhibit production of superoxide but inhibits only its release. Thus, while phagosome-lysosome fusion is inhibited by B. pertussis, respiratory burst activity of PMN occurs at normal levels.

Intracellular survival of virulent Bordetella pertussis in human polymorphonuclear leukocytes.

Little is known regarding the interaction of Bordetella pertussis with polymorphonuclear leukocytes (PMNL) or the role PMNL play as an initial line of defense against B. pertussis infection. An in vitro system was developed to establish conditions for the study of phagocytosis and killing of virulent B. pertussis by human PMNL. Phagocytosis of B. pertussis strains BP504, BP165, and BP338 occurred by opsonization with anti-B. pertussis antibody, while autologous normal human sera did not induce significant phagocytosis. In PMNL bacterial killing assays virulent B. pertussis strains survived PMNL bactericidal activities while Escherichia coli controls were readily killed. Electron microscopy studies using acid phosphatase as a lysosomal marker strongly suggested that B. pertussis inhibits phagosome-lysosome fusion in PMNL. These results indicate that virulent B. pertussis strains are capable of surviving intracellularly within PMNL and that such survival may be due to inhibition of phagosome-lysosome fusion.