Sequential Outbreaks of Infections by Distinct Acinetobacter baumannii Strains in a Public Teaching Hospital in Houston, Texas

Abstract

Invasive disease due to Acinetobacter baumannii is an increasing problem in health care settings worldwide. Whether certain clones of A. baumannii are more likely to cause invasive disease in hospitalized patients is unknown. We studied all patients at a public teaching hospital in Houston, Texas, from whom the Acinetobacter calcoaceticus-Acinetobacter baumannii complex was isolated over a 14-month period in 2005 to 2006. One hundred seven unique patient isolates were identified, with 87 of the strains classified as being A. baumannii, the majority of which were multidrug resistant. The A. baumannii isolates were comprised of 18 unique pulsed-field types, with strains of clone A and clone B accounting for 66 of the 87 isolates. Epidemiologic analysis showed the predominance of the two A. baumannii clones at distinct time periods, with the remainder of the A. baumannii and non-A. baumannii strains being evenly distributed. Patients from whom clone A strains were isolated were more likely to be bacteremic than were patients with other A. baumannii isolates. Conversely, clone B strains were more likely to be isolated from patients with tertiary peritonitis. Patients from whom clone A was isolated had a significantly higher rate of mortality. Multilocus sequence typing demonstrated that clones A and B are related to each other and to A. baumannii strains previously isolated in Western Europe, sharing five of seven alleles. Taken together, we conclude that the outbreak of the A. calcoaceticus-A. baumannii complex in our institution was due to two distinct A. baumannii clones that were associated with significantly different patient outcomes.

Clinical Isolates of Acinetobacter baumannii From Tehran Hospitals: Pulsed-field Gel Electrophoresis Characterization, Clonal Lineages, Antibiotic Susceptibility, and Biofilm-forming Ability

“…Increasing antimicrobial resistance (20) and the ability of A. baumannii to survive on inanimate and dry surfaces are linked to the occurrence of periodic outbreaks observed in various hospitals (21). Acinetobacter baumannii is the most common isolate obtained from skin, blood, sputum, pleural fluid, and urine (22). As many studies show, the organism is most frequently isolated from the respiratory tract than the other body organs among the ICU admitted patients (23,24).…”

Antimicrobial Resistant Determination and Prokaryotic Expression of smpA Gene of Acinetobacter baumannii Isolated from Admitted Patients

“…Multi drug resistant A. baumannii is a common challenge in treatment of hospital infections in many countries, including America, Italy, Korea, Greece, Belgium and Iraq (9)(10)(11)(12)(13)(14).The spread on antibiotic resistance among AcJundishapur J Microbiol. 2017; 10(11):e59370.…”

“…Recently progressive significant increasing of antibiotic resistance in A. baumannii isolates, created a serious threat to hospitalized patients (6,(8)(9)(10)(11). In our study, in around 45% of isolates A. baumannii was diagnosed, the majority of studied patients were hospitalized in the ICU and most samples were isolated from the sputum cultures (50%).…”

“…The above mentioned properties of these species and the emerging antibiotic resistance for A. baumannii, could be related to biofilm formation. Outer membrane proteins (OMPs) are the plentiful surface proteins of this organism cause of nosocomial infections (6,(9)(10)(11)(12)(13)(14)(15). The most important way for restriction of infectious diseases is vaccination.…”

The whole genome sequencing of Acinetobacter-calcoaceticus-baumannii complex strains involved in suspected outbreak in an Intensive Care Unit of a pediatric hospital

“…Indeed, Acinetobacter baumannii is recovered in ventilator-associated pneumonia, catheter-related and wound infections particularly in patients admitted in UTI-Intensive Care Unit (UTI). [3][4][5][6] Furthermore, it is intrinsically resistant to many antimicrobial agents and frequently acquires genetic elements conferring multi-drug resistance (MDR). [7][8][9] Acinetobacter baumannii is resistant to desiccation and to disinfectants, it is difficult to be treated and to be eradicated and it requires rigorous monitoring programs to prevent and control hospital outbreaks.…”