Active surveillance cultures: comparison of inguinal and rectal sites for detection of multidrug-resistant bacteria

High risk of bloodstream infection of carbapenem-resistant enterobacteriaceae carriers in neutropenic children with hematological diseases

BACKGROUND

Neutropenic children with hematological diseases were associated with higher morbidity of carbapenem-resistant enterobacteriaceae (CRE) blood-stream infection (BSI) or colonization. But it was still murky regarding clinical characteristics, antimicrobial susceptibility, and outcomes of CRE-BSI in these patients. We aimed to identify the potential risk factors for subsequent bacteremia and clinical outcome caused by CRE-BSI.

METHODS

Between 2008 and 2020, 2,465 consecutive neutropenic children were enrolled. The incidence and characteristics of CRE-BSI were explored in CRE-colonizers versus non-colonizers. Survival analysis was performed and risk factors for CRE-BSI and 30-day mortality were evaluated.

RESULTS

CRE-carriers were identified in 59/2465 (2.39%) neutropenic children and19/59 (32.2%) developed CRE-BSI, while 12/2406 (0.5%) of non-carriers developed CRE-BSI (P < 0.001). The 30-day survival probability was significantly lower in patients with CRE-BSI than in non-BSI (73.9% vs. 94.9%, P = 0.050). Moreover, the 30-day survival probability of patients with CRE-BSI was also poorer in CRE-carriers versus non-carriers (49.7% vs. 91.7%, P = 0.048). Tigecycline and amikacin exhibited satisfactory antimicrobial activity against all isolated strains. Fluoroquinolone sensitivity was lower in E. coli (26.3%) strains versus satisfactory susceptibility of E. cloacae and other CRE-strains (91.2%). CRE-BSI accompanying intestinal mucosal damage were independent risk factors for 30-day survival probability (both P < 0.05), while combined antibiotic therapy and longer duration of neutropenia were more prone to developed CRE-BSI (P < 0.05).

CONCLUSION

CRE-colonizers were prone to subsequent BSI and CRE-BSI was regarded as an independent predictor predisposing to high mortality in neutropenic children. Moreover, individualized antimicrobial therapy should be adopted due to different features of patients with separate CRE strains.

Rectal swab screening assays of public health importance in molecular diagnostics: Sample adequacy control

Rectal swabs are routinely used by public health authorities to screen for multi-drug resistant enteric bacteria including vancomycin-resistant enterococci (VRE) and carbapenem-resistant enterobacteriaceae (CRE). Screening sensitivity can be influenced by the quality of the swabbing, whether performed by the patient (self-swabbing) or a healthcare practitioner. One common exclusion criterion for rectal swabs is absence of "visible soiling" from fecal matter. In our institution, this criterion excludes almost 10% of rectal swabs received in the microbiology laboratory. Furthermore, over 30% of patients in whom rectal swabs are cancelled will not be re-screened within the next 48h, resulting in delays in removing infection prevention measures. We describe two quantitative polymerase chain reaction (qPCR)-based assays, human RNAse P and eubacterial 16S rDNA, which might serve as suitable controls for sampling adequacy. However, lower amounts of amplifiable human DNA make the 16s rDNA assay a better candidate for sample adequacy control.