Metallo-β-lactamases among Enterobacteriaceae from routine samples in an Italian tertiary-care hospital and long-term care facilities during 2008

Abstract

The emergence of metallo-β-lactamase (MBL)-producing Enterobacteriaceae is a serious public health concern. Producers have been repeatedly isolated from patients and long-term care facility (LTCF) residents around Bolzano, and we sought to assess their prevalence and clinical impact. All routine Enterobacteriaceae isolates from a Bolzano tertiary-care hospital and associated long-term care facilities in 2008 (n = 5500) were screened for MBLs, with case details reviewed for the source patients. In total, 36 producers were obtained from 29 patients, comprising 14 Escherichia coli, six Klebsiella pneumoniae, four Klebsiella oxytoca, four Citrobacter freundii, two Enterobacter cloacae and two Morganella morganii, as well as single Citrobacter amalonaticus, Enterobacter aerogenes, Providencia stuartii and Proteus mirabilis isolates. All were PCR-positive for bla(VIM) and 25 were PCR-positive for qnrS; 19 non-K. pneumoniae had bla(SHV) and one had bla(CTX-M-group1); 13 were from 12 LTCF residents and 23 were from 17 acute-care patients. All these patients had serious underlying diseases with prolonged hospitalization or LTCF stay; only seven had infections due to the MBL producers, comprising four urinary tract infections, two catheter-related bloodstream infections and one patient with both a surgical site infection and pneumonia. Five patients had more than one MBL-producing organism. Pulsed-field gel electrophoresis identified a cluster of six related E. coli, whereas pairs of K. pneumoniae and C. freundii isolates had >85% profile similarity. Transformants prepared from two isolates were shown to be PCR-positive for bla(VIM), qnrS and bla(SHV); their plasmids gave similar restriction fragment length polymorphism patterns, and bla(VIM-1), qnrS1 and bla(SHV-12) were detected by sequencing.

Dominance of CTX-M group 1 beta-lactamase enzymes in ESBL producing E. coli from outpatient urines in neighboring regions of Austria and Italy

“…Similarly, 80% (44/55) of ESBL producing E. coli isolates from screening samples of long-term care facility residents in 2008 had CTX-M group 1 enzymes; sequencing identifi ed them as CTX-M 15, except for one isolate with CTX-M-1 [14]. Th e three detected CTX-M group 9 enzymes from Bolzano in this study also confi rmed previous fi ndings [14,22]. Single E. coli isolates in Innsbruck and Bolzano with CTX-M group 2 enzymes isolated from patients one originating from an unknown source and the other perhaps from Romania confi rm the threat of importation of still rare CTX-M types in our region [23].…”

Emergence of VIM-1-carbapenemase-producing Enterobacter cloacae in Tyrol, Austria

“…Therefore, in our region, colistin seems to be the only reliable antibiotic alternative for severe infections with VIMproducing members of the Enterobacteriaceae, but its use is limited because of adverse toxicity effects. In addition, there are several reports of resistance to colistin from other countries (Livermore et al, 2011;Meletis et al, 2011). PFGE revealed that the spread of VIM-1-producing E. cloacae in Tyrol is mainly due to dissemination of one genotype.…”

“…Carbapenem resistance in clinical isolates of E. cloacae is unusual but has been described in strains with porin alterations combined with the hyperproduction of chromosomal cephalosporinase (Lee et al, 1991), and in strains producing class A carbapenem-hydrolysing nonMBLs (Rasmussen et al, 1996). MBLs have been reported in clinical isolates of E. cloacae from various geographical areas (Aschbacher et al, 2011;Falcone et al, 2009;Queenan & Bush, 2007;Tato et al, 2007;Treviño et al, 2009).…”

Prospective study of bacteremia rate after elective band ligation and sclerotherapy with cyanoacrylate for esophageal varices in patients with advanced liver disease

“…The other case, a different microorganism was isolated after third BL session. The pathogen was Klebsiella oxytoca, a metallo-beta-lactamase-producing Enterobacteriaceae (1) . This microorganism can cause various infectious complications in both healthy and immunocompromised subjects, such as port central venous catheter-associated bloodstream infection (13) , spontaneous peritonitis (16) and malignant external otitis (6) , and was recently described as the causative agent of antibiotic-associated hemorrhagic colitis (8) .…”

“…1 worldwide to arrest bleeding from gastric varices and differs from conventional sclerosants because it polymerizes within seconds on contact with aqueous media (3) . Furthermore, studies have demonstrated the usefulness of CY injection for the treatment of bleeding or no bleeding esophageal varices, especially in ChildPugh C cirrhotic patients (11) .…”