Antimicrobial susceptibility testing and successful treatment of hospitalised patients with extensively drug-resistant Campylobacter jejuni infections linked to a pet store puppy outbreak.

OBJECTIVES: Most patients with Campylobacter infection do not require antibiotics; however, they are indicated in severe cases. Clinical breakpoints for many antibiotics are not yet established by the CLSI, making antibiotic selection for resistant infections challenging. During an outbreak of pet store puppy-associated XDR Campylobacter jejuni infections resistant to seven antibiotic classes, several patients required antibiotics. This study aimed to determine MICs of the outbreak strain for various antibiotics and describes the successful treatment of two patients using imipenem/cilastatin, a drug not traditionally used for Campylobacter infections. METHODS: We used whole-genome multilocus sequence typing (wgMLST) to determine the genetic relatedness of Campylobacter isolates collected from two human patients' stool samples with the outbreak strain. We performed extended antimicrobial susceptibility testing on 14 outbreak isolates and 6 control strains to determine MICs for 30 antibiotics (14 classes). RESULTS: Isolates from both patients were highly related to the outbreak strain by wgMLST. MICs indicated resistance of the outbreak strain to most antibiotic classes, except phenicols, glycylcyclines and carbapenems. Due to potential side effects of phenicols and safety issues precluding use of glycylcyclines such as tigecycline when alternatives agents are available, we used carbapenems to treat patients who were severely ill from the outbreak strain infections. CONCLUSION: Stewardship and clinical vigilance are warranted when deciding whether and how to treat patients with suspected C. jejuni diarrhoea with antibiotics. Clinicians should maintain a high index of suspicion for XDR Campylobacter when patients fail to improve and consider the use of carbapenems in such settings.

Risk Factors for Community-Acquired Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Infections-A Retrospective Study of Symptomatic Urinary Tract Infections.

BACKGROUND: Community-acquired extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL) infections are an evolving public health problem. Identifying predictive risk factors may improve patient management. METHODS: We identified 251 adult inpatients admitted to a 22-hospital system with an ESBL urinary tract infection (UTI) between 2001 and 2016. Cases were matched 1:1 with controls who had a UTI at admission with non-ESBL Enterobacteriaceae. Cases with a history of ESBL infections or hospitalization within 3 months of index admission were excluded. Univariate and multiple logistic regression were used to identify risk factors associated with ESBL UTIs. RESULTS: In univariate analysis, history of repeated UTIs, neurogenic bladder, urinary catheter presence at admission, and exposure to outpatient third-generation cephalosporins or fluoroquinolones within 3 months were associated with higher risk of ESBL UTIs. When controlling for severity of illness and comorbid conditions, history of repeated UTIs (adjusted odds ratio [aOR], 6.40; 95% confidence interval [CI], 3.42-12.66; P < .001), presence of urinary catheter at admission (aOR, 2.36; 95% CI, 1.15-4.98; P < .05), and prior antibiotic exposure (aOR, 7.98; 95% CI, 2.92-28.19; P < .001) remained associated with risk of ESBL infection. CONCLUSIONS: Patients in the community with indwelling urinary catheters, history of recurrent UTIs, or recent antimicrobial use are at higher risk for de novo ESBL Enterobacteriaceae UTIs.

Potentially Serious Drug Interactions Resulting From the Pretravel Health Encounter.

Travelers seen for pretravel health encounters are frequently prescribed new travel-related medications, which may interact with their previously prescribed medications. In a cohort of 76 324 travelers seen at 23 US clinics, we found that 2650 (3.5%) travelers were prescribed travel-related medications with potential for serious drug interactions.