Diagnostic microbiology and infectious disease
-
Diagn. Microbiol. Infect. Dis. · Feb 2006
Simultaneous coinfection by multiple strains during Burkholderia cepacia complex infection in cystic fibrosis.
Much remains unknown about the natural history of respiratory tract infection by Burkholderia cepacia complex (Bcc) in persons with cystic fibrosis (CF). Specifically, it is not clear whether infected CF patients typically harbor a single Bcc strain or multiple strains that may be phenotypically indistinguishable. We genotyped 912 Bcc isolates recovered from CF sputum culture from in excess of 100 patients to demonstrate that chronic infection generally involves a single strain. Transient coinfection with more than 1 strain occurs infrequently and may be more common early in the course of Bcc infection.
-
Diagn. Microbiol. Infect. Dis. · Jan 2006
Contemporary antimicrobial activity of triple antibiotic ointment: a multiphased study of recent clinical isolates in the United States and Australia.
Triple antibiotic ointment (TAO) containing neomycin, polymyxin B, and bacitracin was launched in the 1950s in the United States (USA) as a prescription product and then was used over the counter (OTC) since the 1970s (USA) to prevent superficial wound infections. In Australia, TAO has been restricted to prescription use. This study 1) determined cross-resistance patterns of neomycin compared with other aminoglycosides; 2) determined the level and trend of resistance to TAO and individual components especially versus mupirocin-resistant strains (USA); and 3) established the baseline TAO activity level against pathogens from Australia. ⋯ TAO resistance was rare in the United States after extensive OTC use and was not adversely influenced by decades of parenteral aminoglycoside use. Australian surveillance showed high levels of TAO susceptibility in sampled isolates as a baseline for possible OTC availability. TAO maintains a wider spectrum of activity compared with mupirocin and was usable against mupirocin-resistant Gram-positive strains.
-
Diagn. Microbiol. Infect. Dis. · Aug 2005
Infectious pulmonary complications after stem cell transplantation or chemotherapy: diagnostic yield of bronchoalveolar lavage.
Hematologic patients are at high risk for infectious pulmonary complications after stem cell transplantation (SCT) or chemotherapy. The aim of this study was to detect the range of pulmonary pathogens in these patients, analyzing 95 bronchoalveolar lavage (BAL) samples with classic and molecular (polymerase chain reaction [PCR]) detection methods. Human cytomegalovirus (HCMV) was detected in 33, herpes simplex virus in 21, human herpesvirus 6 in 24, and other viruses in 16 samples. ⋯ Interestingly, a high incidence of polymicrobial infections (50/95) was detected, dominated by HCMV co-infections, especially after allogeneic SCT. Within 3 years of follow-up, a poor outcome of co-infections of Aspergillus species with HCMV in 9 of 10 cases could be documented, whereas only 7 of 20 patients died with noninfectious BAL results. Herpesviruses, fungi, and Gram-positive bacteria were detected most frequently, and in 53%, polymicrobial infections were diagnosed.
-
Diagn. Microbiol. Infect. Dis. · Jul 2005
Comparative StudyAntimicrobial activity of tigecycline tested against organisms causing community-acquired respiratory tract infection and nosocomial pneumonia.
Emerging antimicrobial resistance among respiratory tract pathogens has created a critical need for development of new antimicrobial agents that are not affected by the commonly occurring genetic resistance mechanisms. Tigecycline, a novel broad-spectrum parenteral glycylcycline, has been shown to be active against many of Gram-positive, Gram-negative, atypical, and anaerobic organisms, including strains highly resistant to commonly prescribed antimicrobials and was recently approved by the US Food and Drug Administration for treating infections of skin and skin structures, and for intra-abdominal infections. In this study, tigecycline spectrum and potency were evaluated against a global collection of pathogens (2000-2004) recovered from community-acquired respiratory infections (7580 strains) or from hospitalized patients with pneumonia (3183 strains). ⋯ All E. coli (including 13.3% with an extended-spectrum beta-lactamase [ESBL] phenotype) were inhibited by < or =1 microg/mL, and all Klebsiella (25.8% ESBL phenotype) and Enterobacter spp. plus 97.0% of Serratia spp. were inhibited by < or =4 microg/mL. Tigecycline was also active against Acinetobacter spp. and S. maltophilia strains (MIC50 and MIC90, 1 and 4 microg/mL, respectively). Further clinical studies should consider the role that tigecycline may play in the therapy for severe respiratory tract infections, both of nosocomial and community origin.
-
Diagn. Microbiol. Infect. Dis. · Jul 2005
Antimicrobial activity of tigecycline tested against nosocomial bacterial pathogens from patients hospitalized in the intensive care unit.
The antimicrobial activity of tigecycline and selected antimicrobials was evaluated against bacterial pathogens isolated from patients hospitalized in intensive care units (ICUs) worldwide. A total of 9093 isolates were consecutively collected in >70 medical centers in North America (4157), South America (1830), Europe (3034), and the Asia-Australia (72) areas. The isolates were collected from the bloodstream (68.5%), respiratory tract (13.6%), skin/soft tissue (5.5%), and urinary tract (2.0%) infections in the 2000-2004 period, and susceptibility was tested by reference broth microdilution methods. ⋯ In summary, isolates from ICU patients worldwide showed high rates of antimicrobial resistance. The most alarming problems detected were vancomycin resistance among enterococci, ESBL-mediated beta-lactam resistance and fluoroquinolone resistance among Enterobacteriaceae, and carbapenem resistance among P. aeruginosa and Acinetobacter spp. Tigecycline exhibited potent in vitro activity against most of clinically important pathogenic bacteria (except P. aeruginosa) isolated from ICU patients and may represent an excellent option for the treatment of infections in this clinical environment.