Health Management Associates

About: Health Management Associates is a based out in . It is known for research contribution in the topics: Imipenem & Klebsiella pneumoniae. The organization has 78 authors who have published 259 publications receiving 8860 citations.

Global spread of carbapenem-resistant Acinetobacter baumannii

Abstract: Objectives We have investigated the molecular epidemiology and distribution of carbapenemase genes in 492 imipenem-non-susceptible Acinetobacter baumannii worldwide isolates (North and Latin America, Europe, Asia, South Africa and Australia). Methods MICs were determined by broth microdilution and Etest. The presence of carbapenemase-encoding genes was investigated by PCR. Molecular epidemiology was performed by repetitive sequence-based PCR (rep-PCR; DiversiLab), sequence-type multiplex PCR and PFGE. Results Imipenem non-susceptibility was associated with ISAba1 upstream of the intrinsic bla(OXA-51-like) or the acquired carbapenemase bla(OXA-23-like), bla(OXA-40-like) or bla(OXA-58-like). Isolates were grouped into eight distinct clusters including European clones I, II and III. European clone II was the largest (246 isolates) and most widespread group (USA, pan-Europe, Israel, Asia, Australia and South Africa). Conclusions The global dissemination of eight carbapenem-resistant lineages illustrates the success this organism has had in epidemic spread. The acquired OXA enzymes are widely distributed but are not the sole carbapenem resistance determinant in A. baumannii.

Laboratory Detection of Enterobacteriaceae That Produce Carbapenemases

Abstract: A study was designed to evaluate the modified Hodge test (MHT), Mastdiscs ID inhibitor combination disks (MDI), Rosco Diagnostica Neo-Sensitabs (RDS), metallo-β-lactamase (MBL) Etest, and in-house multiplex PCR for the detection of well-characterized carbapenemase-producing Enterobacteriaceae. One hundred forty-two nonrepeat clinical isolates of carbapenemase-producing Enterobacteriaceae (including Klebsiella spp., Escherichia coli, Citrobacter freundii, and Enterobacter spp.) obtained from the SMART worldwide surveillance program during 2008 to 2009 were included. These included 49 KPC-, 27 NDM-, 19 VIM-, 14 OXA-48-like enzyme-, and 5 IMP-producing isolates and 28 carbapenem-resistant, carbapenemase-negative isolates. The manufacturer9s instructions were followed for MDI, RDS, and MBL Etest and CLSI guidelines for MHT. A multiplex PCR was designed to detect KPC, NDM, VIM, IMP, and OXA-48-like carbapenemases. Overall, the sensitivity and specificity were 78% and 93% for MDI, 80% and 93% for RDS, 58% and 93% for MHT, and 55% and 100% for MBL Etest, respectively. The PCR had 100% sensitivity and specificity. MDI and RDS performed well for the detection of KPCs and NDMs but poorly for VIMs, IMPs, and OXA-48-like enzymes. MHT performed well for KPCs and OXA-48-like enzymes but poorly for NDMs, VIMs, and IMPs. MDI and RDS were easy to perform and interpret but lacked sensitivity for OXA-48-like enzymes, VIMs, and IMPs. MHT and MBL Etest were often difficult to interpret. We recommend using molecular tests for the optimal detection of carbapenemase-producing Enterobacteriaceae.

Antimicrobial-resistant pathogens in intensive care units in Canada: results of the Canadian National Intensive Care Unit (CAN-ICU) study, 2005-2006.

Abstract: Between 1 September 2005 and 30 June 2006, 19 medical centers collected 4,180 isolates recovered from clinical specimens from patients in intensive care units (ICUs) in Canada. The 4,180 isolates were collected from 2,292 respiratory specimens (54.8%), 738 blood specimens (17.7%), 581 wound/tissue specimens (13.9%), and 569 urinary specimens (13.6%). The 10 most common organisms isolated from 79.5% of all clinical specimens were methicillin-susceptible Staphylococcus aureus (MSSA) (16.4%), Escherichia coli (12.8%), Pseudomonas aeruginosa (10.0%), Haemophilus influenzae (7.9%), coagulase-negative staphylococci/Staphylococcus epidermidis (6.5%), Enterococcus spp. (6.1%), Streptococcus pneumoniae (5.8%), Klebsiella pneumoniae (5.8%), methicillin-resistant Staphylococcus aureus (MRSA) (4.7%), and Enterobacter cloacae (3.9%). MRSA made up 22.3% (197/884) of all S. aureus isolates (90.9% of MRSA were health care-associated MRSA, and 9.1% were community-associated MRSA), while vancomycin-resistant enterococci (VRE) made up 6.7% (11/255) of all enterococcal isolates (88.2% of VRE had the vanA genotype). Extended-spectrum beta-lactamase (ESBL)-producing E. coli and K. pneumoniae occurred in 3.5% (19/536) and 1.8% (4/224) of isolates, respectively. All 19 ESBL-producing E. coli isolates were PCR positive for CTX-M, with bla CTX-M-15 occurring in 74% (14/19) of isolates. For MRSA, no resistance against daptomycin, linezolid, tigecycline, and vancomycin was observed, while the resistance rates to other agents were as follows: clarithromycin, 89.9%; clindamycin, 76.1%; fluoroquinolones, 90.1 to 91.8%; and trimethoprim-sulfamethoxazole, 11.7%. For E. coli, no resistance to amikacin, meropenem, and tigecycline was observed, while resistance rates to other agents were as follows: cefazolin, 20.1%; cefepime, 0.7%; ceftriaxone, 3.7%; gentamicin, 3.0%; fluoroquinolones, 21.1%; piperacillin-tazobactam, 1.9%; and trimethoprim-sulfamethoxazole, 24.8%. Resistance rates for P. aeruginosa were as follows: amikacin, 2.6%; cefepime, 10.2%; gentamicin, 15.2%; fluoroquinolones, 23.8 to 25.5%; meropenem, 13.6%; and piperacillin-tazobactam, 9.3%. A multidrug-resistant (MDR) phenotype (resistance to three or more of the following drugs: cefepime, piperacillin-tazobactam, meropenem, amikacin or gentamicin, and ciprofloxacin) occurred frequently in P. aeruginosa (12.6%) but uncommonly in E. coli (0.2%), E. cloacae (0.6%), or K. pneumoniae (0%). In conclusion, S. aureus (MSSA and MRSA), E. coli, P. aeruginosa, H. influenzae, Enterococcus spp., S. pneumoniae, and K. pneumoniae are the most common isolates recovered from clinical specimens in Canadian ICUs. A MDR phenotype is common for P. aeruginosa isolates in Canadian ICUs.

Emergence of High Levels of Extended-Spectrum-β-Lactamase-Producing Gram-Negative Bacilli in the Asia-Pacific Region: Data from the Study for Monitoring Antimicrobial Resistance Trends (SMART) Program, 2007

Abstract: Of 3,004 gram-negative bacilli collected from intra-abdominal infections in the Asia-Pacific region during 2007, 42.2% and 35.8% of Escherichia coli and Klebsiella spp., respectively, were extended-spectrum beta-lactamase (ESBL) positive. Moreover ESBL rates in India for E. coli, Klebsiella pneumoniae, and Klebsiella oxytoca were 79.0%, 69.4%, and 100%, respectively. ESBL-positive E. coli rates were also relatively high in China (55.0%) and Thailand (50.8%). Ertapenem and imipenem were the most active drugs tested, inhibiting over 90% of all species, including ESBL-positive isolates with the exception of Pseudomonas aeruginosa isolates (<90% susceptible to all study drugs) and ESBL-positive Klebsiella pneumoniae isolates (<90% susceptible to all study drugs except imipenem). Quinolones achieved 90% inhibition levels only against ESBL-negative K. pneumoniae and ESBL-negative K. oxytoca. A decline in ampicillin-sulbactam activity was noted, with only 34.5% of all Enterobacteriaceae inhibited in this study.