CD33 has been implicated in the pathogenesis of Alzheimer’s disease primarily through its role in inhibiting the clearance of beta-amyloid (Aβ). However, genetic studies yield mixed results and it is unclear whether the impact of CD33 is specific to Alzheimer’s disease or related to broader neurodegenerative processes. Interestingly, CD33 has also been shown to interact with the hepatitis B (HBV) and C viruses (HCV).

This study aims to investigate the effects of CD33 single-nucleotide polymorphisms (SNPs) on cognitive functions across diverse populations, including healthy controls, individuals with chronic HBV or HCV and those diagnosed with Parkinson’s disease.

We genotyped CD33 SNPs in 563 participants using the Affymetrix platform. Participants’ cognitive functions were cross-sectionally assessed using a neuropsychological test battery spanning six domains.

Our analysis revealed that CD33 SNP variations had no significant cognitive impact on healthy individuals or Parkinson’s disease patients. However, chronic HBV and HCV patients exhibited significant cognitive differences, particularly in memory, related to CD33 SNP genotypes. Moderation analysis indicated a heightened influence of CD33 SNPs on cognitive functions in chronic HBV and HCV individuals. Our data also suggest that inflammation severity may modulate the cognitive effects in hepatitis patients with specific CD33 SNPs.

This study highlights the importance of CD33 SNPs in cognitive outcomes, emphasising their role in the context of chronic viral hepatitis. It contributes to understanding the cognitive profiles influenced by CD33 SNPs and posits CD33’s potential contribution to neurodegenerative disease progression, potentially intensified by HBV/HCV-induced inflammation.

Isolation of multidrug-resistant gram-negative bacteria (MDR-GNB) from patients in the community has been increasingly observed. A prediction model for MDR-GNB colonization and infection risk stratification on hospital admission is needed to improve patient care.

A 2-stage, prospective study was performed with 995 and 998 emergency department patients enrolled, respectively. MDR-GNB colonization was defined as isolates resistant to 3 or more classes of antibiotics, identified in either the surveillance or early (≤48 hours) clinical cultures.

A score-assigned MDR-GNB colonization prediction model was developed and validated using clinical and microbiological data from 995 patients enrolled in the first stage of the study; 122 of these patients (12.3%) were MDR-GNB colonized. We identified 5 independent predictors: age>70 years (odds ratio [OR], 1.84 [95% confidence interval (CI), 1.06–3.17]; 1 point), assigned point value in the model), residence in a long-term-care facility (OR, 3.64 [95% CI, 1.57–8.43); 3 points), history of cerebrovascular accidents (OR, 2.23 [95% CI, 1.24–4.01]; 2 points), hospitalization within 1 month (OR, 2.63 [95% CI, 1.39–4.96]; 2 points), and recent antibiotic exposure (OR, 2.18 [95% CI, 1.16–4.11]; 2 points). The model displayed good discrimination in the derivation and validation sets (area under ROC curve, 0.75 and 0.80, respectively) with the best cutoffs of<4 and ≥4 points for low- and high-risk MDR-GNB colonization, respectively. When applied to 998 patients in the second stage of the study, the model successfully stratified the risk of MDR-GNB infection during hospitalization between low- and high-risk groups (probability, 0.02 vs 0.12, respectively; log-rank test, P<.001).

A model was developed to optimize both the decision to initiate antimicrobial therapy and the infection control interventions to mitigate threats from MDR-GNB.

Infect Control Hosp Epidemiol 2017;38:1216–1225

Ralstonia pickettii has caused contamination of pharmaceutical solutions in many countries, resulting in healthcare infections or outbreak events. We determined the source of the outbreak of R. pickettii bloodstream infection (BSI).

This study was conducted in a 3,000-bed tertiary referral medical center in Taiwan with >8,500 admissions during May 2015. Patients had been treated in the injection room or chemotherapy room at outpatient departments, emergency department, or hospital wards. All patients who were culture positive for R. pickettii from May 3 to June 11, 2015, were eligible for the study. The aim of the survey was to conduct clinical epidemiological and microbiological investigations to identify possible sources of infection.

We collected 57 R. pickettii–positive specimens from 30 case patients. We performed 24 blood cultures; 14 of these revealed >2 specimens and 6 used fluid withdrawn from Port-a-Cath implantable venous access devices. All patients received an injection of 20 mL 0.9% normal saline via catheter flushing. In addition, 2 unopened ampules of normal saline solution (20 mL) were confirmed positive for R. pickettii. The Taiwan Centers for Disease Control and Prevention performed sampling and testing of the same manufactured batch and identified the same strain of R. pickettii. Pulsed-field gel electrophoresis tests revealed that all clinical isolates had similarity of >90%, validating the outbreak of the same clone of R. pickettii.

R. pickettii can grow in saline solutions and cause bloodstream infections. Hospital monitoring mechanisms are extremely important measures in identifying and ending such outbreaks.

Infect Control Hosp Epidemiol 2017;38:444–448