Risk factors for rectal colonization of carbapenem-resistant Enterobacteriaceae in a tertiary care hospital: a case-control study from Turkey

Prevalence and risk factors for colonisation and infection with carbapenem-resistant Enterobacterales in intensive care units: A prospective multicentre study

OBJECTIVES

This study aimed to investigate the prevalence and risk factors for carbapenem-resistant Enterobacterales colonisation/infection at admission and acquisition among patients admitted to the intensive care unit.

RESEARCH METHODOLOGY/DESIGN

A prospective and multicentre study.

SETTING

This study was conducted in 24 intensive care units in Anhui, China.

MAIN OUTCOME MEASURES

Demographic and clinical data were collected, and rectal carbapenem-resistant Enterobacterales colonisation was detected by active screening. Multivariate logistic regression models were used to analyse factors associated with colonisation/infection with carbapenem-resistant Enterobacterales at admission and acquisition during the intensive care unit stay.

RESULTS

There were 1133 intensive care unit patients included in this study. In total, 5.9% of patients with carbapenem-resistant Enterobacterales colonisation/infection at admission, and of which 56.7% were colonisations. Besides, 8.5% of patients acquired carbapenem-resistant Enterobacterales colonisation/infection during the intensive care stay, and of which 67.6% were colonisations. At admission, transfer from another hospital, admission to an intensive care unit within one year, colonisation/infection/epidemiological link with carbapenem-resistant Enterobacterales within one year, and exposure to any antibiotics within three months were risk factors for colonisation/infection with carbapenem-resistant Enterobacterales. During the intensive care stay, renal disease, an epidemiological link with carbapenem-resistant Enterobacterales, exposure to carbapenems and beta-lactams/beta-lactamase inhibitors, and intensive care stay of three weeks or longer were associated with acquisition.

CONCLUSION

The prevalence of colonisation/infection with carbapenem-resistant Enterobacterales in intensive care units is of great concern and should be monitored systematically. Particularly for the 8.5% prevalence of carbapenem-resistant Enterobacterales acquisition during the intensive care stay needs enhanced infection prevention and control measures in these setting. Surveillance of colonisation/infection with carbapenem-resistant Enterobacterales at admission and during the patient's stay represents an early identification tool to prevent further transmission of carbapenem-resistant Enterobacterales.

IMPLICATIONS FOR CLINICAL PRACTICE

Carbapenem-resistant Enterobacterales colonization screening at admission and during the patient's stay is an important tool to control carbapenem-resistant Enterobacterales spread in intensive care units.

Klebsiella oxytoca Complex: Update on Taxonomy, Antimicrobial Resistance, and Virulence

Klebsiella oxytoca is actually a complex of nine species-Klebsiella grimontii, Klebsiella huaxiensis, Klebsiella michiganensis, K. oxytoca, Klebsiella pasteurii, Klebsiella spallanzanii, and three unnamed novel species. Phenotypic tests can assign isolates to the complex, but precise species identification requires genome-based analysis. The K. oxytoca complex is a human commensal but also an opportunistic pathogen causing various infections, such as antibiotic-associated hemorrhagic colitis (AAHC), urinary tract infection, and bacteremia, and has caused outbreaks. Production of the cytotoxins tilivalline and tilimycin lead to AAHC, while many virulence factors seen in Klebsiella pneumoniae, such as capsular polysaccharides and fimbriae, have been found in the complex; however, their association with pathogenicity remains unclear. Among the 5,724 K. oxytoca clinical isolates in the SENTRY surveillance system, the rates of nonsusceptibility to carbapenems, ceftriaxone, ciprofloxacin, colistin, and tigecycline were 1.8%, 12.5%, 7.1%, 0.8%, and 0.1%, respectively. Resistance to carbapenems is increasing alarmingly. In addition to the intrinsic bla_OXY, many genes encoding β-lactamases with varying spectra of hydrolysis, including extended-spectrum β-lactamases, such as a few CTX-M variants and several TEM and SHV variants, have been found. bla_KPC-2 is the most common carbapenemase gene found in the complex and is mainly seen on IncN or IncF plasmids. Due to the ability to acquire antimicrobial resistance and the carriage of multiple virulence genes, the K. oxytoca complex has the potential to become a major threat to human health.

Raoultella terrigena: Current state of knowledge, after two recently identified clinical cases in Eastern Europe

Raoultella terrigena is a rarely found opportunistic pathogen that can cause healthcare-associated infections with high mortality. It is important to differentiate it from Klebsiella species.

Risk factors for fecal carriage of extended-spectrum beta-lactamase-producing and carbapenem-resistant Escherichia coli and Klebsiella pneumoniae strains among patients at hospital admission

AIM

Extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) Enterobacteriaceae are substantial problems in hospital-acquired infections worldwide. We analyzed the risk factors for fecal carriage of ESBL-positive and/or CR E. coli and K. pneumoniae (EcKp) strains in a hospital in Turkey, an endemic country for both resistances.

MATERIALS AND METHODS

A prospective cross-sectional study including the rectal swab samples of 168 patients, obtained at the day of admission, was conducted. ESBL-producing and CR EcKp were investigated with phenotypic tests and PCR, and the clonal relatedness of isolates was studied. Risk analysis was performed with logistic regression method.

RESULTS

A total of 67 (39.8%) and 21 (12.5%) patient samples tested positive for ESBL-producing and CR EcKp, respectively. CTX-M (n = 27) and OXA-48 (n = 12) were the dominant ESBL and carbapenemase types, and 4.5%-10.7% of the isolates were clonally-related. Among 15 potential risk factors studied, longer lengths of hospital stay and antimicrobial use, and receiving total parenteral nutrition in the last 6 months were determined as independent risk factors for fecal carriage of ESBL-producing and/or CR EcKp, while prior antimicrobial treatment was only a risk factor for ESBL producers.

CONCLUSION

Certain conditions in patients' medical backgrounds may be associated with increased likelihood of resistant bacterial colonization. Notably, questioning these situations at admission can help to identify potential carriers and proactively administer appropriate infection control measures.

Risk factors and outcomes of patients colonized with carbapenemase-producing and non–carbapenemase-producing carbapenem-resistant Enterobacteriaceae

Objective:

To compare risk factors and outcome of patients colonized with carbapenemase-producing (CP) carbapenem-resistant Enterobactereaceae (CRE) and non–CP-CRE.

Design:

A comparative historical study.

Setting:

A 1,000-bed tertiary-care university hospital.

Patients:

Adults with CP-CRE positive rectal swab cultures, non–CP-CRE positive rectal swab cultures, and negative rectal swab cultures (non-CRE).

Methods:

CP-CRE and non–CP-CRE colonized adult patients versus patients not colonized with CRE hospitalized during 24 months were included. We identified patients retrospectively through the microbiology laboratory, and we reviewed their files for demographics, underlying diseases, Charlson Index, treatment, and outcome.

Results:

This study included 447 patients for whom a rectal swab for CRE was obtained: 147 positive for CP-CRE, 147 positive for non–CP-CRE, and 147 negative for both. Patients with CP-CRE and non–CP-CRE versus no CRE more frequently resided in nursing homes (P<0.001), received antibiotics 3 months prior to admission (P < .001), and received glucocorticosteroids 3 months prior to admission (P = .047 and P < .001, respectively). Risk factors unique for non–CP-CRE versus CP-CRE colonization included mechanical ventilation and patient movement between hospital departments. Non–CP-CRE was a predictor for mechanical ventilation 2.5 that of CP-CRE colonization. In-hospital mortality was highest among non–CP-CRE–colonized patients. On COX multivariate regression for mortality prediction age, Charlson index and steroid treatment 3 months before admission influenced mortality (P = .027, P = .023, and P = .013, respectively).

Conclusions:

Overlapping and unique risk factors are associated with CP-CRE and non–CP-CRE colonization. Non–CP-CRE colonized patients had a higher in-hospital mortality rate.