A Pseudoepidemic Due to Laboratory Contamination Deciphered by Molecular Analysis

Morris, Thomas W.; Brecher, Stephen M.; Fitzsimmons, Dianne; Durbin, Annette; Arbeit, Robert D.; Maslow, Joel N.

doi:10.1086/647061

Cited by 8 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We demonstrated that in such cases, RAPD analysis might be a very useful method for determining the clinical relevance of the cultured isolate. For bacterial pathogens, genotyping to determine the clinical relevance of an isolate has been described previously (14).…”

Section: Fig 3 Pcr Typing Of a Fumigatus Isolatesmentioning

confidence: 99%

Density and Molecular Epidemiology of Aspergillus in Air and Relationship to Outbreaks of Aspergillus Infection

et al. 1999

View full text Add to dashboard Cite

After five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus andA. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in Rotterdam (The Netherlands) was begun. A. fumigatus isolates obtained from the Department of Hematology were studied for genetic relatedness by randomly amplified polymorphic DNA (RAPD) analysis. This was repeated with A. fumigatus isolates contaminating culture media in the microbiology laboratory. The density of the conidia of nonpathogenic fungi in the outside air showed a seasonal variation: higher densities were measured during the summer, while lower densities were determined during the fall and winter. Hardly any variation was found in the numbers of Aspergillus conidia. We found decreasing numbers of conidia when comparing air from outside the hospital to that inside the hospital and when comparing open areas within the hospital to the closed department of hematology. The increase in the number of patients with invasive aspergillosis could not be explained by an increase in the number ofAspergillus conidia in the outside air. The short-term presence of A. flavus can only be explained by the presence of a point source, which was probably patient related. Genotyping A. fumigatus isolates from the department of hematology showed that clonally related isolates were persistently present for more than 1 year. Clinical isolates of A. fumigatus obtained during the outbreak period were different from these persistent clones. A. fumigatus isolates contaminating culture media were all genotypically identical, indicating a causative point source. Knowledge of the epidemiology of Aspergillus species is necessary for the development of strategies to prevent invasive aspergillosis. RAPD fingerprinting of Aspergillus isolates can help to determine the cause of an outbreak of invasive aspergillosis.

show abstract

Section: Fig 3 Pcr Typing Of a Fumigatus Isolatesmentioning

confidence: 99%

Density and Molecular Epidemiology of Aspergillus in Air and Relationship to Outbreaks of Aspergillus Infection

et al. 1999

View full text Add to dashboard Cite

show abstract

“…This situation may result from systemic extrinsic contamination during specimen collection or processing or intrinsic contamination at the time the culture medium 21,22) .…”

Section: Discussionmentioning

confidence: 99%

Molecular Epidemiology ofBacillus cereusin a Pediatric Cancer Center

Kim

Park

Lee³

et al. 2016

Pediatr Infect Vaccine

View full text Add to dashboard Cite

Purpose: Bacillus cereus has been reported as the cause of nosocomial infections in cancer patients. In our pediatric cancer ward, a sudden rise in the number of patients with B. cereus bacteremia was observed in 2013 to 2014. This study was performed to investigate the molecular epidemiology of increased B. cereus bacteremia cases in our center. Methods: Pediatric cancer patients who developed B. cereus bacteremia were identified from January 2001 to June 2014. The B. cereus bacteremia in this study was defined as a case in which at least one B. cereus identified in blood cultures, regardless of true bacteremia. Available isolates were further tested by multilocus sequence typing (MLST) analysis. A retrospective chart review was performed. Results: Nineteen patients developed B. cereus bacteremia during the study period. However, in 2013, a sudden increase in the number of patients with B. cereus bacteremia was observed. In addition, three patients developed B. cereus bacteremia within 1 week in July and the other three patients within 1 week in October, respectively, during emergency room renovation. However, MLST analysis revealed different sequence types without consistent patterns. Before 2013, five tested isolates were ST18, ST26, ST177, and ST147-like type, and ST219-like type. Isolates from 2013 were ST18, ST73, ST90, ST427, ST784, ST34-like type, and ST130-like type. Conclusions: MLST analyses showed variable ST distribution of B. cereus isolates. Based on this study, there was no significant evidence suggesting a true outbreak caused by a single ST among patients who developed B. cereus bacteremia.

show abstract

“…Among the disinfectants commonly used in hospitals, 70 to 90% ethyl alcohol is an excellent intermediate-level germicide but it is not a sporocide. Spore-forming bacteria, such as Bacillus species and Clostridium species, can survive in 70 or 90% ethyl alcohol (2,7,12,15,22). Iodine-containing disinfectant has reliable sporicidal activity (2,3).…”

Section: Discussionmentioning

confidence: 99%

“…Previous reports showed that 11% of the nosocomial outbreaks were in fact pseudoepidemics (in which an organism is isolated above the normal baseline frequency) (15,17,22). Recognizing and tracking the origin of such pseudoepidemics is difficult and requires the aid of attending physicians, infection control personnel, and clinical microbiologists (12,14).…”

mentioning

confidence: 99%

Nosocomial Pseudoepidemic Caused by Bacillus cereus Traced to Contaminated Ethyl Alcohol from a Liquor Factory

et al. 1999

View full text Add to dashboard Cite

From September 1990 to October 1990, 15 patients who were admitted to four different departments of the National Taiwan University Hospital, including nine patients in the emergency department, three in the hematology/oncology ward, two in the surgical intensive care unit, and one in a pediatric ward, were found to have positive blood (14 patients) or pleural effusion (1 patient) cultures for Bacillus cereus. After extensive surveillance cultures, 19 additional isolates of B. cereus were recovered from 70% ethyl alcohol that had been used as a skin disinfectant (14 isolates from different locations in the hospital) and from 95% ethyl alcohol (5 isolates from five alcohol tanks in the pharmacy department), and 10 isolates were recovered from 95% ethyl alcohol from the factory which supplied the alcohol to the hospital. In addition to these 44 isolates of B. cereus, 12 epidemiologically unrelated B. cereus isolates, one Bacillus sphaericus isolate from a blood specimen from a patient seen in May 1990, and two B. sphaericus isolates from 95% alcohol in the liquor factory were also studied for their microbiological relatedness. Among these isolates, antibiotypes were determined by using the disk diffusion method and the E test, biotypes were created with the results of the Vitek Bacillus Biochemical Card test, and random amplified polymorphic DNA (RAPD) patterns were generated by arbitrarily primed PCR. Two clones of the 15 B. cereus isolates recovered from patients were identified (clone A from 2 patients and clone B from 13 patients), and all 29 isolates of B. cereus recovered from 70 or 95% ethyl alcohol in the hospital or in the factory belonged to clone B. The antibiotype and RAPD pattern of the B. sphaericus isolate from the patient were different from those of isolates from the factory. Our data show that the pseudoepidemic was caused by a clone (clone B) of B. cereus from contaminated 70% ethyl alcohol used in the hospital, which we successfully traced to preexisting contaminated 95% ethyl alcohol from the supplier, and by another clone (clone A) without an identifiable source.

show abstract

A Pseudoepidemic Due to Laboratory Contamination Deciphered by Molecular Analysis

Abstract: The application of molecular typing clearly demonstrated clonality among the isolates and indicated that a common source of contamination, most likely the CMGB tubes, was responsible for these cases.

Cited by 8 publications

References 0 publications

Density and Molecular Epidemiology of Aspergillus in Air and Relationship to Outbreaks of Aspergillus Infection

Density and Molecular Epidemiology of Aspergillus in Air and Relationship to Outbreaks of Aspergillus Infection

Molecular Epidemiology ofBacillus cereusin a Pediatric Cancer Center

Nosocomial Pseudoepidemic Caused by Bacillus cereus Traced to Contaminated Ethyl Alcohol from a Liquor Factory

Contact Info

Product

Resources

About