Blood Culture Positivity: Is It Pathogen or Contaminant?

Basit Öğe Kaydı
dc.contributor.authorBalikci, Ahmet
dc.contributor.authorBelas, Zeliha
dc.contributor.authorEren Topkaya, Aynur
dc.date.accessioned2024-07-12T21:52:11Z
dc.date.available2024-07-12T21:52:11Z
dc.date.issued2013en_US
dc.departmentMaltepe Üniversitesien_US
dc.description.abstractBlood culture is the gold standard for diagnosis of bloodstream infections. Many studies have shown that rapid isolation and identification of the microorganisms in blood culture and initiation of early antimicrobial therapy are critically important to reduce the mortality rate. It was found that the rate of contamination in blood cultures is increasing with automated systems developed to facilitate the growth of microorganism and tracking positivity. It is more difficult to interpret a positive blood culture result especially in the case of having only one sample bottle. In this study the effect of growth time observed in the automated blood culture systems was evaluated in terms of interpretation of blood culture results as being pathogens or contaminants. A total of 1201 blood cultures tested in BACTEC 9120 (Becton Dickinson, USA) system in Maltepe University Hospital Medical Microbiology Laboratory, Istanbul, Turkey during one-year period were included in the study and growth times were recorded for positive bottles. The decision about the growth as being a pathogen or contamination was made by considering the clinical condition of the patient, the number of positive blood cultures and the results of inflammation markers (white blood cell counts, procalsitonin and CRP levels). Of the blood cultures 290 (24%) yielded positive results and 73% (212/290) of them were evaluated as pathogens, while 27% (78/290) were identified as contaminants. The mean detection time for clinically significant isolates was 17.87 hours and for contaminants was 40.56 hours. The difference between the growth time of pathogens and contaminants was found statistically significant (p< 0.0001). With regard to all positive results, it was detected that 66% of the bacteria grew within the first 24 hours. While 29.6% of the pathogens grew within 12 hours, none of the contaminants grew during that time. The evaluation of growth time among staphylococci in terms of methicillin resistance revealed that methicillin- resistant staphylococci grew later (26 hours) than the susceptible ones (11 hours) both in the pathogen group and the contaminant group (p< 0.01). The data of our study emphasized that, the growth time detected in blood culture systems had a critical role in estimating whether the isolated microorganism is a pathogen or a contaminant, especially in case of lack of more than one blood samples. It was concluded that, the bacterial growth detected within the first 24 hours most probably indicated the microorganism as pathogen, while blood culture positivity detected after 48 hours strongly pointed out that it was contaminant. However, it should be considered that methicillin-resistant staphylococci needed much longer time than 24 hour for growth, both as pathogens or contaminants.en_US
dc.identifier.endpage140en_US
dc.identifier.issn0374-9096
dc.identifier.issue1en_US
dc.identifier.pmid23390910en_US
dc.identifier.scopusqualityQ4en_US
dc.identifier.startpage135en_US
dc.identifier.urihttps://hdl.handle.net/20.500.12415/8353
dc.identifier.volume47en_US
dc.identifier.wosWOS:000339539000014en_US
dc.identifier.wosqualityQ4en_US
dc.indekslendigikaynakWeb of Science
dc.indekslendigikaynakPubMed
dc.language.isotren_US
dc.publisherANKARA MICROBIOLOGY SOCen_US
dc.relation.ispartofMIKROBIYOLOJI BULTENIen_US
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanıen_US
dc.rightsinfo:eu-repo/semantics/closedAccessen_US
dc.snmzKY02928
dc.subjectBlood cultureen_US
dc.subjectdetection timesen_US
dc.subjectstaphylococcien_US
dc.subjectmethicillin resistanceen_US
dc.titleBlood Culture Positivity: Is It Pathogen or Contaminant?en_US
dc.typeArticle
dspace.entity.typePublication

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