Acinetobacter Baumannii Colonization Research Articles

P231: Risk factors for Acinetobacter baumannii colonization and infection among patients admitted to intensive care units

failure (32.3%) and post surgery (30.2%). Fourteen patients (7%) were found to be AB colonized at ICU admission, whereas 9 (4.5%) became colonized during ICU stay within a median of 7 days (IQR 6-10). Significant differences between AB colonized and non-colonized patients at ICU admission were found for septic shock (21.4% vs. 4.3%) and prior antibiotic therapy (78.6% vs. 43.3%). Conclusion Our preliminary analysis showed that prior antibiotic therapy and septic shock were significantly associated with AB colonization at ICU admission.

Risk factors for acquired multidrug-resistant Acinetobacter baumannii colonization in respiratory intensive care unit

To determine the risk factors for respiratory intensive care unit (RICU)-acquired colonization of multidrug-resistant Acinetobacter baumannii (MDR-AB). From January 2010 to June 2011, active screening was performed to define patients with RICU-acquired colonization of MDR-AB. And environment surveillance was carried out and patient data were collected. Logistic regression was applied to identify the risk factors of RICU-acquired colonization of MDR-AB. Active screening for MDR-AB was performed for 110 patients in RICU and 50 patients turned out to be positive. After eliminating 3 input positive patients, the RICU-acquired colonization rate of MDR-AB was 43.9% (47/107). The environmental contaminated rate of MDR-AB was 66.0% (31/47) for 47 positive patients and 33.9% (19/56) for 56 negative ones (χ(2) = 10.494, P < 0.01). Five risk factors were associated with the colonization of MDR-AB through univariate analysis: consciousness disturbance, use of carbapenems, nasal feeding tube, endotracheal intubation and mechanical ventilation (all P < 0.05). The Logistic regression equation contained 3 risk factors of conscious disturbance, use of carbapenems and mechanical ventilation (OR = 3.412, 3.211, 3.002; 95% CI: 1.165 - 9.992, 1.117 - 9.233, 1.101 - 8.182). Three risk factors are independently associated with the RICU-acquired colonization of MDR-AB: consciousness disturbance, use of carbapenems and mechanical ventilation.

Quantitative Real-Time PCR for Detection of Acinetobacter baumannii Colonization in the Hospital Environment

A real-time PCR assay was developed for detecting the presence of Acinetobacter baumannii on hospital equipment and compared to conventional bacterial culture using 100 hospital environmental samples. The real-time PCR detected contaminated surfaces in 4 h with high sensitivity (100%) compared to conventional culture. Thirty-eight percent of samples were positive by real-time PCR and negative by bacterial culture (false positives), possibly indicating the widespread presence of bacterial DNA that is not associated with viable bacteria.

Three-Dimensional Human Skin Equivalent as a Tool To Study Acinetobacter baumannii Colonization

Acinetobacter baumannii can colonize body surfaces of hospitalized patients. From these sites, invasion into the host and spread to other patients and the hospital environment may occur. The eradication of the organism from the patient's skin is an important infection control strategy during epidemic and endemic episodes. In this study, a three-dimensional (3D), air-exposed human epidermal skin equivalent was exploited to study Acinetobacter skin colonization. We characterized the adherence of A. baumannii ATCC 19606(T) and Acinetobacter junii RUH2228(T) to and biofilm formation on the skin equivalent and the responses to these bacteria. Furthermore, we assessed the ability of the disinfectant chlorhexidine to decolonize the skin equivalents. The results revealed that both strains replicated on the stratum corneum for up to 72 h but did not invade the epidermis. A. baumannii, in contrast to A. junii, formed large biofilms on the stratum corneum. Bacterial colonization did not affect keratinocyte activation, proliferation, or differentiation, nor did it induce a strong inflammatory response. Disinfection with chlorhexidine solution resulted in complete eradication of A. baumannii from the skin, without detrimental effects. This 3D model is a promising tool to study skin colonization and to evaluate the effects of novel disinfectant and antimicrobial strategies.

Control of an Outbreak of Multi-drug Resistant Acinetobacter Baumannii Colonization in a Neonatal Intensive Care Unit

Outbreaks of multi-drug resistant Acinetobacter Baumannii (MDR-Ab) frequently occur in adult intensive care units, however, it is rarely reported as the source of an outbreak in neonatal intensive care units (NICU). The first appearance of Acinetobacter Baumannii in our NICU, and the presumed index was admitted to the NICU 28 days prior to identification of MDR-Ab in his sputum. This positive culture initiated an investigation. Between January 2010 and February 2010, 7 neonates were identified with MDR-Ab colonization, 6 in the sputum and one from a rectal culture. We describe our investigation of an outbreak of MDR-Ab colonization in our NICU, and discuss methods used to control transmission.

Low prevalence of Acinetobacter baumannii colonization on hospital admission

We conducted a prospective cohort study of non-critically ill patients admitted to a tertiary care center between December 2003 and September 2004 and obtained perirectal samples at hospital admission to determine the prevalence of Acinetobacter baumannii. A baumannii was isolated from 1 of 555 cultures (0.18%); no multidrug-resistant A baumannii was identified. Interventions aimed at early identification of A baumannii-colonized patients may not benefit by widely targeting non-critically ill patients on hospital admission.

Outbreak of resistant Acinetobacter baumannii: measures and proposal for prevention and control

Acinetobacter baumannii colonization and infection, frequent in Intensive Care Unit (ICU) patients, is commonly associated with high morbimortality. Several outbreaks due to multidrug-resistant (MDR) A. baumanii have been reported but few of them in Brazil. This study aimed to identify risk factors associated with colonization and infection by MDR and carbapenem-resistant A. baumannii strains isolated from patients admitted to the adult ICU at HC/UFMG. A case-control study was performed from January 2007 to June 2008. Cases were defined as patients colonized or infected by MDR/carbapenem-resistant A. baumannii, and controls were patients without MDR/carbapenem-resistant A. baumannii isolation, in a 1:2 proportion. For statistical analysis, due to changes in infection control guidelines, infection criteria and the notification process, this study was divided into two periods. During the first period analyzed, from January to December 2007, colonization or infection by MDR/carbapenem-resistant A. baumannii was associated with prior infection, invasive device utilization, prior carbapenem use and clinical severity. In the multivariate analysis, prior infection and mechanical ventilation proved to be statistically significant risk factors. Carbapenem use showed a tendency towards a statistical association. During the second study period, from January to June 2008, variables with a significant association with MDR/carbapenem-resistant A. baumannii colonization/infection were catheter utilization, carbapenem and third-generation cephalosporin use, hepatic transplantation, and clinical severity. In the multivariate analysis, only CVC use showed a statistical difference. Carbapenem and third-generation cephalosporin use displayed a tendency to be risk factors. Risk factors must be focused on infection control and prevention measures considering A. baumanni dissemination.

Prévalence un jour donné du portage d' Acinetobacter baumannii chez les patients de 53 réanimations françaises

Objective This study was made to evaluate multiresistant Acinetobacter baumannii colonization in French intensive care units. Design We conducted a prevalence study on the carriage of A. baumannii for a one-day period in various French ICUs. On December 10, 2003, one nasal and/or rectal swab sampling was performed in 506 patients of 53 ICUs. Results Sixteen patients (3.16%) from 7 centers (13%) were colonized by A. baumannii. None of the known risk factors for colonization by multiresistant A. baumannii were identified in these patients. Conclusions Overall, A. baumannii colonization is limited except during epidemic situations. Our study reflects the carriage of A. baumannii in ICUs on a given day. This study showed that there was no multiresistant A. baumannii epidemic clone, potentially responsible for outbreaks, present in the tested French ICUs.

Role of environmental cleaning in controlling an outbreak of Acinetobacter baumannii on a neurosurgical intensive care unit

An outbreak of Acinetobacter baumannii colonization and infection occurred in 19 patients over a 14-month period during 1998-1999 on a neurosurgical intensive care unit. During efforts to control the outbreak a significant correlation was observed between the number of environmental isolates of A. baumannii obtained during each monthly screening and the number of patients with A. baumannii colonization/infection in the same calendar month (P=0.004). Use of 1000 ppm hypochlorite solution and the introduction of new cleaning protocols reduced the number of environmental isolates. Failure to maintain low levels of environmental contamination with A. baumannii resulted in increases in patient colonization. This study showed that high standards of cleaning play an integral role in controlling outbreaks of A. baumannii in the intensive care unit setting.

Role of environmental cleaning in controlling an outbreak of Acinetobacter baumannii on a neurosurgical intensive care unit

An outbreak of Acinetobacter baumannii colonization and infection occurred in 19 patients over a 14-month period during 1998–1999 on a neurosurgical intensive care unit. During efforts to control the outbreak a significant correlation was observed between the number of environmental isolates of A. baumannii obtained during each monthly screening and the number of patients with A. baumannii colonization/infection in the same calendar month ( P=0.004). Use of 1000 ppm hypochlorite solution and the introduction of new cleaning protocols reduced the number of environmental isolates. Failure to maintain low levels of environmental contamination with A. baumannii resulted in increases in patient colonization. This study showed that high standards of cleaning play an integral role in controlling outbreaks of A. baumannii in the intensive care unit setting.

Risk factors for nosocomial colonization with multiresistantAcinetobacter baumannii

A six-month prospective survey was carried out in a university hospital to assess the incidence of Acinetobacter baumannii cross-contamination and to identify risk factors for colonization. Clinical isolates obtained during the study period were biotyped and genotyped by pulsed-field gel electrophoresis after ApaI macrorestriction of total DNA. Case-control univariate and multivariate analyses were performed to identify risk factors for Acinetobacter baumannii colonization. One hundred forty-seven patients hospitalized in 36 units were colonized or infected, of whom 52 were in three intensive care units. The urinary (29%) and bronchopulmonary tracts (26%) were the most frequently colonized sites. Nine major restriction patterns were identified: two were exhibited by epidemic multi-resistant strains of biotype 9 which were isolated from 65 patients hospitalized in ten units. Multivariate analysis showed that case-patients were (a) more likely than non-infected controls to be male, to have been previously hospitalized in another unit and to have had longer stays in the unit before colonization and hyperalimentation; and (b) more likely than controls colonized with other gram-negative bacilli to be male, to have had longer hospitalization, to have received treatment with third-generation cephalosporins and to have had a urinary catheter. The high incidence of colonization with Acinetobacter baumannii can thus be attributed to frequent cross-contamination and the use of broad-spectrum antibiotics. Colonized patients appear to be the major source of cross-contamination as epidemic strains spread throughout the hospital.