Association of proton pump inhibitors with the occurrence of gut-derived bacteraemia in patients with haematological malignancy after chemotherapy

Prevalence and factors associated with carbapenem-resistant Enterobacterales (CRE) infection among hematological malignancies patients with CRE intestinal colonization

BACKGROUND

Knowledge about the prevalence, factors and mortality associated with subsequent carbapenem-resistant Enterobacterales (CRE) infection among hematological malignancies (HM) patients colonized with CRE is limited.

METHODS

HM patients were screened for rectal CRE. A retrospective case-control study of subsequent CRE infection among HM patients colonized with CRE was conducted between January 1st, 2020 and January 31st, 2022. Cases were defined as CRE colonized patients with subsequent infection and controls were those without infection. Bacterial identification was performed using MALDI Biotyper and antimicrobial susceptibility testing of strains was carried out using the VITEK 2 system or standard broth microdilution method. Logistic analysis was used for analyzing associated factors and Kaplan-Meier method was used for survival estimates.

RESULTS

A total of 953 HM patients were screened for rectal CRE and 98 (10.3%, 98/953) patients were colonized with CRE. Among the 98 colonized patients, 18 (18.4%, 18/98) patients developed subsequent infection. Most of the colonizing CRE isolates were Klebsiella pneumoniae (50.0%, 27/54), followed by Escherichia coli (27.8%, 15/54) and Enterobacter cloacae (9.3%, 5/54). As for the subsequent infecting CRE isolates, the dominated species was K. pneumoniae (55.6%, 10/18), followed by E. coli (33.3%, 6/18) and others (11.2%, 2/18). Receiving proton pump inhibitors and admission to ICU (P < 0.05) were the associated factors. Patients with subsequent CRE infection had significant higher mortality (33.3% vs 2.8%, P = 0.001) and shock was an associated factor (P = 0.008).

CONCLUSIONS

Klebsiella pneumoniae was the dominate colonizing species and subsequent infecting species among HM patients with CRE colonization. Receiving proton pump inhibitors and admission to ICU increased the risk of subsequent CRE infection among CRE colonized HM patients. Implementing strict infection control measures targeting those high- risk patients may prevent subsequent CRE infection.

Clinical features and outcomes of bacteremic and non-bacteremic Campylobacteriosis: a case-control study

PURPOSE

Campylobacter bloodstream infection (C-BSI) is uncommon, and its clinical significance is unclear. The aim of the study was to determine risk factors and clinical outcomes associated with Campylobacter BSI.

METHODS

We performed a single center retrospective case-control study comparing patients with C-BSI (cases) and patients with nonbacteremic Campylobacter enteritis (controls), from January 2007 through June 2020. Case and control patients were matched by age and sex at a ratio of 1:2. Demographic, clinical, and microbiological characteristics were compared between groups.

RESULTS

We identified 76 patients with C-BSI and matched them with 149 nonbacteremic patients with Campylobacter enteritis. Rates of C-BSI increased tenfold in 2014 following the introduction of BacTAlert FA/FN Plus blood culture bottles. Baseline variables significantly associated with C-BSI on multivariable logistic regression were fever, absence of diarrhea and recent exposure to antibiotics. Compared with controls, C-BSI was associated with higher 30-day mortality (12% vs. 2%, P = 0.003), more frequent need for intensive care (6.6% vs. 1.2%, P = 0.032) and longer hospital stay (median, 5 days vs. 3 days, P = 0.003). There was a high proportion of immunocompromised patients in both groups (55%).

CONCLUSIONS

C-BSI is identified with increasing frequency, reflecting both changes in epidemiology and improved sensitivity of blood culture systems. Our findings indicate that detection of Campylobacter spp. in blood culture is associated with significantly higher rates of death and other adverse outcomes.

Association of proton pump inhibitor use with the development of febrile neutropenia in lymphoma patients

Background: Proton pump inhibitors (PPIs), although relatively safe drugs for reduction of gastric acid production, continue to raise concerns (i.e. potential infectious complications, electrolyte disturbances). PPIs are frequently administered to hemato-oncological patients receiving chemotherapy. The study main objective is to investigate whether PPI use by hemato-oncological patients receiving chemotherapy raises the risk of febrile neutropenia.Methods: This is a retrospective database study of patients under hemato-oncological follow up between January 2007 and December 2015, treated with different chemotherapy regimens. Comparative analysis assessed frequencies and types of febrile neutropenia among patients with or without PPI treatment. Multivariate analyses were performed adjusting for age, sub-type of malignancy and specific PPI administered.Results: 247 patients were included, 18-91 years of age (mean 61.6 ± 16), 120 (48.58%) female; amongst 66 (26%) how were hospitalized for febrile neutropenia, 50 (75.8%) received PPIs.Multivariate analysis found three risk factors associated with the development of febrile neutropenia in hematological patients: age, diffuse large B-cell lymphoma and treatment with PPIs.Conclusion: A statistically significant association was demonstrated between PPI treatment and the development of febrile neutropenia among hemato-oncological patients. The clinical implications necessitate further caution in administering PPIs to patients with hematological malignancy receiving chemotherapy.

Anti-Acid Drug Treatment Induces Changes in the Gut Microbiome Composition of Hemodialysis Patients

Anti-acid drugs, proton pump inhibitor (PPI) and histamine-2 blocker (H₂-blocker), are commonly prescribed to treat gastrointestinal disorders. These anti-acid drugs alter gut microbiota in the general population, but their effects are not known in hemodialysis patients. Hence, we investigated the microbiota composition in hemodialysis patients treated with PPIs or H₂-blocker. Among 193 hemodialysis patients, we identified 32 H₂-blocker users, 23 PPI users, and 138 no anti-acid drug subjects. Fecal samples were obtained to analyze the gut microbiome using 16S RNA amplicon sequencing. Differences in the microbial composition of the H₂-blocker users, PPI users, and controls were assessed using linear discriminant analysis effect size and the random forest algorithm. The species richness or evenness (α-diversity) was similar among the three groups, whereas the inter-individual diversity (β-diversity) was different between H₂-blocker users, PPI users, and controls. Hemodialysis patients treated with H₂-blocker and PPIs had a higher microbial dysbiosis index than the controls, with a significant increase in the genera Provetella 2, Phascolarctobacterium, Christensenellaceae R-7 group, and Eubacterium oxidoreducens group in H₂-blocker users, and Streptococcus and Veillonella in PPI users. In addition, compared to the H₂-blocker users, there was a significant enrichment of the genera Streptococcus in PPI users, as confirmed by the random forest analysis and the confounder-adjusted regression model. In conclusion, PPIs significantly changed the gut microbiota composition in hemodialysis patients compared to H₂-blocker users or controls. Importantly, the Streptococcus genus was significantly increased in PPI treatment. These findings caution against the overuse of PPIs.

Is there a role for proton pump inhibitor prophylaxis in haematology patients?

While proton pump inhibitors (PPI) are widely prescribed as prophylaxis in selected haematology inpatient and outpatients, an informal survey of haematology units around Australia found wide variations in the specific indications for their use. This is consistent with a literature review which showed a paucity of robust evidence to support their use, specifically in chemotherapy-induced mucositis, thrombocytopenia or administration of high dose glucocorticosteroids in the absence of additional risk factors. Rationalising PPI prescribing is clinically important from both a cost and safety perspective, given the emerging evidence of adverse events associated with prolonged PPI administration. A review of prescribing practices at our institution over a 14-month period found that approximately 60% of myeloma, lymphoma and autograft patients received PPI prophylaxis during and beyond chemotherapy without an accepted indication. We encourage institutions to review their PPI prescribing practices with the intent of rationalising their use, and to conduct studies aiming to fill the substantial gaps in our knowledge.

Gut Microbiota Composition Before and After Use of Proton Pump Inhibitors

BACKGROUND

Recently, problems associated with proton pump inhibitor (PPI) use have begun to surface. PPIs influence the gut microbiota; therefore, PPI use may increase the risk of enteric infections and cause bacterial translocation. In this study, we investigated fecal microbiota composition, fecal organic acid concentrations and pH, and gut bacteria in the blood of the same patients before and after PPI use.

METHODS

Twenty patients with reflux esophagitis based on endoscopic examination received 8 weeks of treatment with PPIs. To analyze fecal microbiota composition and gut bacteria in blood and organic acid concentrations, 16S and 23S rRNA-targeted quantitative RT-PCR and high-performance liquid chromatography were conducted.

RESULTS

Lactobacillus species were significantly increased at both 4 and 8 weeks after PPI treatment compared with bacterial counts before treatment (P = 0.011 and P = 0.002, respectively). Among Lactobacillus spp., counts of the L. gasseri subgroup, L. fermentum, the L. reuteri subgroup, and the L. ruminis subgroup were significantly increased at 4 and 8 weeks after treatment compared with counts before treatment. Streptococcus species were also significantly increased at 4 and 8 weeks after PPI treatment compared with counts before treatment (P < 0.01 and P < 0.001, respectively). There was no significant difference in the total organic acid concentrations before and after PPI treatment. Detection rates of bacteria in blood before and after PPI treatment were 22 and 28%, respectively, with no significant differences.

CONCLUSIONS

Our quantitative RT-PCR results showed that gut dysbiosis was caused by PPI use, corroborating previous results obtained by metagenomic analysis.