Fatal group C streptococcal infection due to transfusion of a bacterially contaminated pooled platelet unit despite routine bacterial culture screening.

BACKGROUND: An elderly man with chronic myelomonocytic leukemia developed respiratory distress and died less than 48 hours after transfusion of a pool of eight whole blood-derived platelets (PLTs). Blood cultures from the recipient and cultures of remnants from the pooled PLT bag grew group C streptococci (GCS). An investigation was conducted to identify both the infection's source and the reasons for the false-negative screening result. STUDY DESIGN AND METHODS: Red blood cell (RBC) units (cocomponent from the eight donations) were traced, quarantined, and cultured. Specimens from the implicated donor were obtained. Isolates were identified and typed by 16S rRNA and pulsed-field gel electrophoresis (PFGE). The blood center screening method was reviewed. RESULTS: beta-Hemolytic GCS, cultured from 1 of 8 RBC units, linked the fatal case to a single donor. The donor's throat swab collected 20 days after donation was positive for the presence of GCS, identified as Streptococcus dysgalactiae subsp. equisimilis. Isolates from the recipient, RBC unit, residual PLTs, and donor's throat swab were indistinguishable by PFGE. The donor denied any symptoms of infection before or after donation. PLT bacterial screening at the blood center was performed using a commercially available bacterial detection system (BacT/ALERT, bioMérieux) with a threshold of 15 colony-forming units per bag. CONCLUSION: An asymptomatic donor was implicated as the source of GCS-contaminated PLTs. Current screening methods for PLTs are not sufficient to detect all bacterial contamination. Pooled PLTs are a particular challenge because the small volume of individual units places limits on culturing strategies. Improved detection of bacterial contamination of PLTs is needed.

Differences between ceftriaxone and cefotaxime: microbiological inconsistencies.

OBJECTIVE: To review data to determine why pneumococcal isolates appear to be increasingly resistant to cefotaxime, historically regarded as having the same in vitro susceptibility to ceftriaxone, and what this observation might imply clinically. DATA SOURCES: Literature was accessed through MEDLINE (1966-October 2007) using the MeSH terms cefotaxime, ceftriaxone, susceptibility, microbial sensitivity tests, antibiotics, pneumococcal infections, Streptococcus pneumoniae, resistance, and cephalosporin resistance. Abstracts and surveillance databases were reviewed and unpublished data were provided by state departments of health and institutions. STUDY SELECTION AND DATA EXTRACTION: All articles published in the English language that were identified from the data sources were evaluated. DATA SYNTHESIS: An experimental model of pneumococcal infection in mice conducted 2 decades ago predicted that the delta T minimum inhibitory concentration (MIC) varied less for ceftriaxone than for cefotaxime. Studies of plasma and serum concentrations show that ceftriaxone remains at a concentration above the S. pneumoniae MIC for 100% of the dosing interval at 12 hours. Types of MIC susceptibility test methods for ceftriaxone and cefotaxime used against S. pneumoniae respiratory isolates were found to be similar. Data from state and county health departments found microbiological discrepancies between ceftriaxone and cefotaxime. In areas with high rates of penicillin-resistant S. pneumoniae (PRSP), isolates were twice as susceptible to ceftriaxone versus cefotaxime. Surveillance databases consistently show differences between susceptibility of S. pneumoniae to cefotaxime versus ceftriaxone over time. MIC and pulsed-field gel electrophoresis studies suggest that phenotypic discrepancies may account for penicillin resistance. Ongoing studies are examining S. pneumoniae isolates at the molecular level to determine the basis of difference in resistance to cefotaxime and ceftriaxone. CONCLUSIONS: An increase in rates of PRSP and differences in S. pneumoniae isolate susceptibility between ceftriaxone and cefotaxime emphasize the necessity for hospital laboratories to detect these changes as they occur. Clinicians should select the most appropriate agent for patients with S. pneumoniae.

Fatal necrotizing pneumonia due to a Panton-Valentine leukocidin positive community-associated methicillin-sensitive Staphylococcus aureus and Influenza co-infection: a case report.

Recent studies have described a number of fatalities due to methicillin-resistant Staphylococcus aureus (MRSA) and influenza virus co-infection. MRSA isolates provide a challenge to caregivers due to inherent wide range antibiotic resistance. Many facilities have instituted screening methods, based on the presence of antibiotic resistance genes, to identify MRSA positive patients upon admission. However, the resistance profile of the pathogen does not necessarily determine the severity of disease caused by that organism. We describe a fatal case of necrotizing pneumonia in a patient co-infected with Influenza B and a community-associated, PVL-positive methicillin-susceptible Staphylococcus aureus (MSSA).

Multistate outbreak of Burkholderia cenocepacia colonization and infection associated with the use of intrinsically contaminated alcohol-free mouthwash.

BACKGROUND: No guidelines exist for the type of mouthwash that should be used in patients at increased risk for pneumonia. In 2005, we investigated a multistate outbreak of Burkholderia cenocepacia associated with an intrinsically contaminated alcohol-free mouthwash (AFM). METHODS: We conducted a case-series investigation. We used repetitive extragenic palindromic- polymerase chain reaction typing and pulsed-field gel electrophoresis (PFGE) to characterize available Burkholderia cepacia complex (Bcc) isolates from patients and implicated AFM. Seeding studies were conducted to determine the antimicrobial activity of the AFM. RESULTS: Of the 116 patients with Bcc infection or colonization identified from 22 hospitals with culture dates from April 7 through August 31, 2005, 105 had infections or colonizations that were due to B cenocepacia. The median age of these 105 patients was 64 years (range, 6 to 94 years), 52% were women, 55% had evidence of infection, and 2 patients died. Of 139 patient culture specimens, 83 (60%) were from the respiratory tract. Among 103 Bcc patient isolates characterized, 81 (76%) had an indistinguishable PFGE pattern compared to the outbreak strain cultured from implicated lots of unopened AFM; the species was B cenocepacia. Seeding studies showed that the contaminated AFM might have had inadequate amounts of the antimicrobial agent cetylpyridinium chloride. CONCLUSIONS: This intrinsically contaminated AFM led to a geographically dispersed outbreak of B cenocepacia. AFM without therapeutic label claims is regulated by the US Food and Drug Administration as a cosmetic rather than a drug and is therefore subject to limited quality control requirements. Clinicians should be aware that AFM is not sterile. Its use in intubated and other patients with increased risk of aspiration should be avoided.

Outbreak of healthcare-associated infection and colonization with multidrug-resistant Salmonella enterica serovar Senftenberg in Florida.

BACKGROUND: In July 1999, a rare strain of multidrug-resistant Salmonella enterica serovar Senftenberg was isolated from the sputum of a trauma patient. Over a 6-year period (1999-2005) in northeast Florida, this Salmonella serovar spread to 66 other patients in 16 different healthcare facilities as a result of frequent transfers of patients among institutions. To our knowledge, this is the first outbreak of healthcare-associated infection and colonization with a fluoroquinolone-resistant strain of S. Senftenberg in the United States. OBJECTIVES: To investigate an outbreak of infection and colonization with an unusual strain of S. Senftenberg and assist with infection control measures. DESIGN: A case series, outbreak investigation, and microbiological study of all samples positive for S. Senftenberg on culture. SETTING: Cases of S. Senftenberg infection and colonization occurred in hospitals and long-term care facilities in 2 counties in northeast Florida. RESULTS: The affected patients were mostly elderly persons with multiple medical conditions. They were frequently transferred between healthcare facilities. This Salmonella serovar was capable of long-term colonization of chronically ill patients. All S. Senftenberg isolates tested shared a similar pulsed-field gel electrophoresis (PFGE) pattern. CONCLUSION: A prolonged outbreak of infection and colonization with multidrug-resistant S. Senftenberg was identified in several healthcare facilities throughout the Jacksonville, Florida, area and became established when infection control measures failed. The bacterial agent was capable of long-term colonization in chronically ill patients. Because the dispersal pattern of this strain suggested a breakdown of infection control practices, a multipronged intervention approach was undertaken that included intense education of personnel in the different institutions, interinstitutional cooperation, and transfer paperwork notification.

Early identification and control of carbapenemase-producing Klebsiella pneumoniae, originating from contaminated endoscopic equipment.

Klebsiella producing carbapenemase is an emerging pathogen. We report transmission of this organism by contaminated endoscopic instruments. Quick identification of source, staff education, contact precautions, and emphasis on hand and environmental hygiene led to case control and prevention of outbreak.