Abstract
To clarify the risk factors for carriage of metallo-beta-lactamase (MBL)-producing Enterobacteriaceae, we conducted a case-control study by surveying stool specimens from 74 institutionalized patients. MBL-producing Enterobacteriaceae were detected in 14% of the patients (10/74). Compared with controls, the use of a percutaneous endoscopic gastrostomy (PEG) tube was significantly more common (70.0% vs 28.1%, p = 0.009), and the administration of a proton pump inhibitor (PPI) was significantly more frequent (70.0% vs 28.1%, p = 0.009) in carriers. The use of antibiotics in the previous 3 months was not associated with MBL carriage. The average duration of hospital stay in carriers was 26 months, nearly twice as long as that in controls. Multivariate regression analysis revealed that the combination of PEG use and PPI administration was highly associated with MBL carriage [odds ratio (OR) 15.6, 95% confidence interval (CI), 1.4–164.4, p = 0.021]. The relative risks of MBL carriage were 14.7 in the patients using PPI [95% CI, 1.8–121.4, p = 0.013] and 3.9 in the patients with a PEG tube [95% CI, 0.8–19.3, p = 0.098]. After careful infection control activities, we were able to further decrease the detection rate of MBL-producing organisms in stool samples from inpatients with these risks. Our results indicate that the patients using PEG or PPI have a high risk of colonization of the gastrointestinal tract with MBL-producing organisms, and these high-risk groups should be the priority targets for MBL screening in long-term-care patients.
