Simultaneous peritoneal dialysis-associated peritonitis and bacteremia due to ceftriaxone-resistant Campylobacter fetus

Phenotypic and genetic analyses of two Campylobacter fetus isolates from a patient with relapsed prosthetic valve endocarditis

Campylobacter fetus can cause intestinal and systemic disease in humans and are well established veterinary and economic pathogens. We report the complete genomic sequences of two C. fetus subsp. fetus (Cff) isolates recovered in 2017 (CITCf01) and 2018 (CITCf02) from a case of recurrent prosthetic valve endocarditis. Both were capable of growth aerobically. Their genomes were found to be highly conserved and syntenic with 99.97% average nucleotide identity (ANI) while differences in their respective sap loci defined the temporal separation of their genomes. Based on core genome phylogeny and ANI of 83 Cff genomes belonging to the previously described human-associated Cff lineage, CITCf01 and CITCf02 grouped in a clade of eleven sequence type (ST)3 Cff (including the Cff type strain NCTC 10842T). CITCf01 and CITCf02 were marked for their lack of unique genomic features when compared to isolates within the subspecies and the type strain in particular. We identified point mutations in oxidative stress response genes, among others, that may contribute to aerobiosis. We report a case of Cff causing relapsed prosthetic valve endocarditis and we highlight the sap island as a polymorphic site within the genetically stable ST3 lineage, central to pathogenicity.

Incidence and clinical features of patients with peritoneal dialysis peritonitis complicated by bacteremia

The standard treatment of peritoneal dialysis peritonitis (PD peritonitis) is intraperitoneal antibiotic therapy. In patients with PD peritonitis complicated by bacteremia, intraperitoneal antibiotics combined with elective removal of the infected intraperitoneal catheter may be inadequate.We collected data of all patients with PD peritonitis admitted to Chi-Mei Medical Center during a 4-year period. We reviewed the medical records of the study cohort and collected their in-hospital details. Patients with positive blood culture results were assigned to the bacteremia group, whereas those with negative blood culture results were assigned to the peritonitis-only group.We discovered that 11.0% of patients with PD peritonitis had bacteremia complications, and immunocompromised comorbidities were more common in the bacteremia group than in the peritonitis-only group (66.7% vs 37.2%, P = .022). Additionally, the bacteremia group exhibited higher temperatures, greater respiratory rates, and lower serum sodium levels than the peritonitis-only group (temperature, 37.7 vs 37.2 °C, P = .014; respiratory rate, 19.1 vs 17.9 rate/min, P = .008; serum sodium level, 130.3 vs 132.7 mEq/L, P = .031). No mortality was found in patients with PD peritonitis complicated by bacteremia after intravenous and intraperitoneal antibiotic therapy.More than 1 in 10 patients with PD peritonitis was complicated by bacteremia, which resulted in extensive systemic derangements. Patients with immunocompromised comorbidities carried a higher risk of developing bacteremia, resulting in prolonged hospital stays. Combination of intraperitoneal and intravenous antibiotics therapies achieved fair prognoses in patients with PD peritonitis complicated by bacteremia.

Antimicrobial Resistance in Campylobacter Species: Mechanisms and Genomic Epidemiology

The Campylobacter genus is a large and diverse group of Gram-negative bacteria that are known to colonize humans and other mammals, birds, reptiles, and shellfish. While it is now recognized that several emerging Campylobacter species can be associated with human disease, two species, C. jejuni and C. coli, are responsible for the vast majority of bacterial gastroenteritis in humans worldwide. Infection with C. jejuni, in particular, has also been associated with a number of extragastrointestinal manifestations and autoimmune conditions, most notably Guillain-Barré syndrome. The antimicrobial drugs of choice for the treatment of severe Campylobacter infection include macrolides, such as erythromycin, clarithromycin, or azithromycin. Fluoroquinolones, such as ciprofloxacin, are also commonly used for empirical treatment of undiagnosed diarrheal disease. However, resistance to these and other classes of antimicrobial drugs is increasing and is a major public health problem. The US Centers for Disease Control and Prevention estimates that over 300,000 infections per year are caused by drug-resistant Campylobacter. In this chapter, we discuss the taxonomy of the Campylobacter genus, the clinical and global epidemiological aspects of Campylobacter infection, with an emphasis on C. jejuni and C. coli, and issues related to the treatment of infection and antimicrobial resistance mechanisms. We further discuss the use of next-generation sequencing for the detection and surveillance of antimicrobial resistance genes.

Clinical and epidemiological analysis of Campylobacter fetus subsp. fetus infections in humans and comparative genetic analysis with strains isolated from cattle

Background

Campylobacter fetus subspecies fetus (CFF) is an important pathogen for both cattle and humans. We performed a systematic epidemiological and clinical study of patients and evaluated the genetic relatedness of 17 human and 17 bovine CFF isolates by using different genotyping methods. In addition, the serotype, the dissemination of the genomic island containing a type IV secretion system (T4SS) and resistance determinants for tetracycline and streptomycin were also evaluated.

Methods

The isolates from patients diagnosed with CFF infection as well as those from faecal samples of healthy calves were genotyped using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), as well as single locus sequence typing (SLST) targeting cmp1 and cmp2 genes encoding two major outer membrane proteins in CFF. The presence of the genomic island and identification of serotype was determined by PCRs targeting genes of the T4SS and the sap locus, respectively. Tetracycline and streptomycin resistance phenotypes were determined by minimal inhibitory concentration. Clinical data obtained from medical records and laboratory data were supplemented by data obtained via telephone interviews with the patients and treating physicians.

Results

PFGE analysis defined two major clusters; cluster A containing 16 bovine (80 %) isolates and cluster B containing 13 human (92 %) isolates, suggesting a host preference. Further genotypic analysis using MLST, SLST as well as sap and T4SS PCR showed the presence of genotypically identical isolates in cattle and humans. The low diversity observed within the cmp alleles of CFF corroborates the clonal nature of this pathogen. The genomic island containing the tetracycline and streptomycin resistance determinants was found in 55 % of the isolates in cluster A and correlated with phenotypic antibiotic resistance.

Conclusions

Most human and bovine isolates were separated on two phylogenetic clusters. However, several human and bovine isolates were identical by diverse genotyping methods, indicating a possible link between strains from these two hosts.

Campylobacter Fetus Meningitis in Adults: Report of 2 Cases and Review of the Literature

The zoonotic pathogen Campylobacter fetus is a rare cause of bacterial meningitis. Little is known about the clinical characteristics, predisposing factors and outcome of C fetus meningitis in adults.We report cases of C fetus meningitis in a nationwide cohort study of adult bacterial meningitis patients in the Netherlands and performed a review of the literature.Two patients with C fetus meningitis were identified from January 2006 through May 2015. The calculated annual incidence was 0.02 per million adults. Combined with the literature, we identified 22 patients with a median age of 48 years. An immunocompromised state was present in 16 patients (73%), mostly due to alcoholism (41%) and diabetes mellitus (27%). The source of infection was identified in 13 out of 19 patients (68%), consisting of regular contact with domestic animals in 5 and working on a farm in 4. Recurrent fever and illness was reported in 4 patients (18%), requiring prolonged antibiotic treatment. Two patients died (9%) and 3 survivors (15%) had neurological sequelae.C fetus is a rare cause of bacterial meningitis and is associated with an immunocompromised state. Based on the apparent slow clinical response seen in this limited number of cases, the authors of this study recommend a prolonged course of antimicrobial therapy when C fetus is identified as a causative agent of bacterial meningitis. Cases appeared to do best with carbapenem therapy.

Campylobacter peritonitis complicating peritoneal dialysis: a review of 12 consecutive cases

BACKGROUND

Peritoneal dialysis-associated peritonitis secondary to Campylobacter organisms is uncommon. Few studies have assessed either treatment or clinical outcomes.

METHODS

We reviewed all Campylobacter peritonitis episodes occurring in a single dialysis unit from 1994 to 2011.

RESULTS

During the study period, 12 episodes of Campylobacter peritonitis (0.45% of all peritonitis episodes) were recorded. Diarrhea was uncommon (8.3%). The overall primary response rate was 91.7%; the complete cure rate was 75.0%. Among 6 patients who failed to respond to standard antibiotics by day 5, all improved after administration of an oral macrolide (erythromycin or clarithromycin). Of those 6 patients, 5 experienced a complete cure, and 1 patient experienced relapse of culture-negative peritonitis. No patient required Tenckhoff catheter removal or temporary hemodialysis support. The 30-day mortality was 0%.

CONCLUSIONS

Campylobacter peritonitis might not respond to first-line conventional antibiotics, and an oral macrolide is recommended if Campylobacter is confirmed. The findings from our analysis do not support the use of fluoroquinolone, which is associated with a high resistance rate.

An unusual cause of spontaneous bacterial peritonitis due to Campylobacter fetus with alcoholic liver cirrhosis

A 40-year-old man with severe alcoholic liver cirrhosis with a 2-day history of fatigue and abdominal pain was admitted. He reported eating sushi and sliced raw chicken a few days previously. His abdomen was distended, with shifting dullness. Based on the patient's history, physical examination and the results of abdominocentesis, he was diagnosed as having spontaneous bacterial peritonitis; blood and ascitic fluid cultures were positive for Campylobacter fetus. The patient was started on treatment with cefotaxime, which was switched after 1 week to ampicillin for an additional 3 weeks. The patient was successfully treated with the 4-week course of intravenous antibiotic therapy.