Risk Factors for Healthcare-Associated Extensively Drug-Resistant <i>Acinetobacter baumannii</i> Infections: A Case-Control Study

<div><p>The emergence of extensively drug-resistant <i>Acinetobacter baumannii</i> (XDRAB) is a serious threat to hospitalized patients. From 2008 to 2010, surveillance detected 25 hospital-acquired infection (HAI) cases caused by XDRAB at a medical center in Taipei. The site of XDRAB infection was bloodstream (n = 8), urinary tract (n = 12), lower respiratory tract (n = 3), surgical site (n = 1), and cardiovascular (n = 1). The isolates were resistant to all currently available antibiotics except for colistin. The XDRAB isolates are genetically diverse, shown by pulsed-field gel electrophoresis, but 23 of 25 harbored class 1 integron with a 2.3-kb gene cassette. Most of these isolates carry OXA-23 (n = 21) and OXA-51-like carbapenemase genes (n = 25). To identify the risk factors, a case-control study was conducted. The 25 cases were compared with 100 controls randomly selected from hospitalized patients without XDRAB-HAIs, matched by the onset date, ward, and age, at a ratio of 1∶4. Prior use of imipenem, meropenem, piperacillin/tazobactam or fourth-generation cephalosporins (adjusted OR: 3.2, 95% CI: 1.03–10.2, <i>P</i> = 0.04) and >30 days bed-ridden (adjusted OR: 6.0, 95% CI: 1.3–27.6, <i>P</i> = 0.02) were found to be the independent risk factors for XDRAB-HAIs. These findings highlight that, even in the absence of clonal dissemination, XDRAB can emerge under the selective pressure of broad-spectrum antibiotics and causes subsequent HAIs in compromised hosts. An appropriate response to the XDRAB threat therefore should include a component of prudent use of broad-spectrum antibiotics active against gram-negative bacteria.</p></div

Risk factors for XDRAB-HAIs: multivariate analyses.

<p><b>Note</b>: Data are numbers of patients, unless otherwise indicated.</p><p>OR: odds ratio.</p><p>*Statistically significant.</p

Pulsed-field gel electrophoresis (PFGE) dendrogram of XRDAB.

<p>The scale indicates the percentage of genetic similarity. 14 pulsotypes (A–N) and 20 pulsosubtypes (A–D, E1–E2, F1–F3, G–J, K1–K2, L1–L2, M1–M2, N) were identified.</p

Additional file 1: of Potential effects of valproate and oxcarbazepine on growth velocity and bone metabolism in epileptic children- a medical center experience

The orginal data of the study. (XLSX 19 kb

Antimicrobial susceptibility for methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) colonizing isolates in Taiwanese children, 2004-2009.

<p>H, Health maintenance visits; K, Kindergartens; ST, sequence type; TMP-SMX, trimethoprim-sulfamethoxazole.</p>a<p><i>p</i> value derived from comparison of isolates of ST59 and ST338 clonal type (chi-square test, unless otherwise indicated).</p>b<p>Multiresistance to at least 3 of the 10 non-β-lactam antimicrobial agents tested.</p>c<p><i>p</i><0.05 across surveys (2004–2006 vs. 2007–2009, Fisher's exact test).</p

Prevalence of <i>Staphylococcus aureus</i> and methicillin-resistant <i>S. aureus</i> (MRSA) nasal colonization in children with different demographic characteristics, across surveys (2004–2006 vs. 2007–2009).

<p>CI, confidence interval.</p><p><i>*p</i><0.01,</p><p><i>**p</i><0.0001,</p><p><i>***p</i><0.001.</p

Risk factors associated with methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) nasal colonization in children by multivariate analysis using polytomous logistic regression.

<p>CI, confidence interval; OR, odds ratio.</p>a<p>OR (95% CI) was presented as MRSA colonization vs. no. <i>S. aureus</i> colonization; <i>p</i> value of overall model was calculated by the Mantel-Haenszel test.</p><p><i>*p</i><0.05,</p><p><i>**p</i><0.01,</p><p><i>***p</i><0.0001,</p><p><i>****p</i><0.001.</p

Prevalence of molecular traits among methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) isolates recovered from MRSA-colonized children, by study variable, 2004-2009.

<p>CI, confidence interval; PVL, Panton-Valentine leukocidin; SCC<i>mec</i>, staphylococcal cassette chromosome <i>mec</i>; ST, sequence type.</p>a<p>Reference group.</p><p><i>*p</i><0.05,</p><p><i>**p</i><0.0001.</p

Annual prevalence of methicillin-resistant <i>Staphylococcus aureus</i> and methicillin-susceptible <i>S. aureus</i> nasal colonization in Taiwanese children, 2004–2009.

<p>Annual prevalence of methicillin-resistant <i>Staphylococcus aureus</i> and methicillin-susceptible <i>S. aureus</i> nasal colonization in Taiwanese children, 2004–2009.</p

Origin, year and clonal type-specific characteristics of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) colonizing isolates in Taiwanese children.

<p>ETA, exfoliative toxin A; ETB, exfoliative toxin B; H, Health maintenance visits; K, Kindergartens; SEA, staphylococcal enterotoxin A; SEB, staphylococcal enterotoxin B; SEC, staphylococcal enterotoxin C; SED, staphylococcal enterotoxin D; SEE, staphylococcal enterotoxin E; SEG, staphylococcal enterotoxin G; SEH, staphylococcal enterotoxin H; SEI, staphylococcal enterotoxin I; ST, sequence type; TMP-SMX, trimethoprim-sulfamethoxazole; SST-1, toxic shock syndrome toxin-1.</p>a<p><i>p</i> value derived from comparison of isolates of ST59 and ST338 clonal type.</p