Antimicrobial susceptibility testing of 59 strains of Campylobacter fetus subsp. fetus

Antimicrobial resistance in Campylobacter fetus: emergence and genomic evolution

Campylobacter fetus is a pathogen, which is primarily associated with fertility problems in sheep and cattle. In humans, it can cause severe infections that require antimicrobial treatment. However, knowledge on the development of antimicrobial resistance in C. fetus is limited. Moreover, the lack of epidemiological cut-off values (ECOFFs) and clinical breakpoints for C. fetus hinders consistent reporting about wild-type and non-wild-type susceptibility. The aim of this study was to determine the phenotypic susceptibility pattern of C. fetus and to determine the C. fetus resistome [the collection of all antimicrobial resistance genes (ARGs) and their precursors] to describe the genomic basis of antimicrobial resistance in C. fetus isolates over time. Whole-genome sequences of 295 C. fetus isolates, including isolates that were isolated in the period 1939 till the mid 1940s, before the usage of non-synthetic antimicrobials, were analysed for the presence of resistance markers, and phenotypic antimicrobial susceptibility was obtained for a selection of 47 isolates. C. fetus subspecies fetus (Cff) isolates showed multiple phenotypic antimicrobial resistances compared to C. fetus subspecies venerealis (Cfv) isolates that were only intrinsic resistant to nalidixic acid and trimethoprim. Cff isolates showed elevated minimal inhibitory concentrations for cefotaxime and cefquinome that were observed in isolates from 1943 onwards, and Cff isolates contained gyrA substitutions, which conferred resistance to ciprofloxacin. Resistances to aminoglycosides, tetracycline and phenicols were linked to acquired ARGs on mobile genetic elements. A plasmid-derived tet(O) gene in a bovine Cff isolate in 1999 was the first mobile genetic element observed, followed by detection of mobile elements containing tet(O)-aph(3')-III and tet(44)-ant(6)-Ib genes, and a plasmid from a single human isolate in 2003, carrying aph(3')-III-ant(6)-Ib and a chloramphenicol resistance gene (cat). The presence of ARGs in multiple mobile elements distributed among different Cff lineages highlights the risk for spread and further emergence of AMR in C. fetus. Surveillance for these resistances requires the establishment of ECOFFs for C. fetus.

Cervical osteomyelitis potentially caused by Campylobacter fetus

Campylobacter fetus is a rare pathogen in humans. It mainly causes invasive infections in immunosuppressed patients. Herein, we report the first case of cervical vertebral osteomyelitis in a previously healthy man with a history of daily alcohol consumption. Treatment was given for six weeks with excellent clinical recovery and normalization of laboratory markers.

Campylobacter fetus bacteremia and meningitis in an acute lymphoblastic leukemia patient undergoing maintenance therapy: a case report

BACKGROUND

Campylobacter fetus is an uncommon Campylobacter species, and its infections mainly cause infective endocarditis, aortic aneurysm, and meningitis rather than enteritis. It is more likely to be detected in blood than Campylobacter jejuni or Campylobacter coli, specifically reported in 53% of patients. In our case, C. fetus was detected in both blood and cerebrospinal fluid (CSF) cultures.

CASE PRESENTATION

A 33-year-old woman, who was on maintenance chemotherapy for acute lymphoblastic leukemia (ALL), presented to our clinic with chief complaints of severe headache and nausea. Blood and CSF cultures revealed C. fetus. We administrated meropenem 2 g intravenously (IV) every 8 h for 3 weeks, and she was discharged without neurological sequelae.

CONCLUSION

We encountered a case of C. fetus meningitis without gastrointestinal symptoms, neck stiffness or jolt accentuation in a patient with ALL. Undercooked beef was considered the source of C. fetus infection in this case, suggesting that the need for a neutropenic diet and safe food handling be considered.

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.

Infective abdominal aortitis due to Campylobacter fetus bacteremia: A case report and review of literature

Infectious aortitis (IA) is a rare but life-threatening condition, and most commonly affects the abdominal aorta or thoracic aorta. Various microorganisms have been associated with infectious thoracic aortitis, most commonly Staphylococcus, Enterococcus, Streptococcus, and Salmonella species. Campylobacter fetus (C. fetus) has been seen as a cause of infective aortitis only in a few case reports. We report a rare case of infective aortitis of the abdominal aorta caused due to C. fetus bacteremia. While C. fetus infections usually occur in patients with immunosuppression, such as malignancy, or those with diabetes mellitus, but our patient was not immunocompromised. Furthermore, the IA occurred in the absence of an aortic aneurysm, unlike its usual presentation. Thus, it is extremely important to establish an early diagnosis of IA and find out the causative organism for appropriate medical treatment, because this condition is potentially life threatening.

Campylobacter bacteraemia: 16 years of experience in a single centre

BACKGROUND

Campylobacter bacteraemia (CB) is rare and usually occurs in immune-compromised patients. In this study we examined the incidence and epidemiology of CB in one institution over 15.5 years.

METHODS

The medical records of all the consecutive patients with CB admitted to our hospital from 2000 to 2015 were retrospectively reviewed. Clinical characteristics, microbiologic and outcome data were collected.

RESULTS

During the study period, 65 patients with CB were identified. The majority of the patients were middle aged and immune-compromised. Campylobacter jejuni was the most commonly identified species (33/47, 70%). The main underlying conditions were haematological malignancies (43%) and chronic liver disease (14%). Fifty-seven percent of the patients were receiving immunosuppressive therapy at the time of bacteraemia. The most common presenting symptoms were fever (85%), diarrhoea (40%), abdominal pain (40%), and nausea and vomiting (40%). Of the isolates tested, 97% were susceptible to macrolides, and only 35% were susceptible to quinolones. Susceptibility to quinolones decreased over the years. Most patients did not receive adequate empiric antibiotic treatment (81.5%) and about 20% never received directed therapy. Mortality and relapse rates were low (5% each). There was no association between adequate empirical or definitive antibiotic therapy and adverse outcomes.

CONCLUSION

The main predisposing factor for Campylobacter bacteraemia in our cohort was immunosuppression. Prognosis was generally favourable regardless of appropriateness of antibiotic therapy.

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.

Frequency of methicillin-resistant Staphylococcus aureus nasal carriage in healthy children

BACKGROUND AND OBJECTIVE

The prevalence of community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) is increasing around the world. It involves healthy people and causes a variety of diseases.

MATERIAL AND METHODS

This cross sectional study was conducted from September 2010-June 2011 on children less than 14 years of Ahvaz, southwest Iran. The participants were selected with two staged cluster sampling. A sterile cotton nasal swab was used to collect the samples from the 864 participants. MRSA isolates were identifed by catalase and coagulase tests and 1 μg oxacillin disk method. Polymerase chain reaction (PCR) was performed on all the MRSA colonies to detect the mecA gene. Data was put in SPSS 16 software and descriptive statistics and chi-square test were used for analysis.

RESULTS

Out of 864 children, 471 (54.51%) were male and 393 (45.49%) were female. 235 children (27.1%) had Staphylococcus aureus and 11 (1.3%) of all children diagnosed with MRSA. PCR showed that 7 colonies (0.8%) had the mecA gene.

CONCLUSION

The results of this study indicate that MRSA exists in healthy children of Ahvaz. Although the prevalence of CA-MRSA is lower than many other regions, it still needs close attention to prevent its transmission. Further studies are needed to identify the risk factors of CA-MRSA.

Two novel antibiotic resistance genes, tet(44) and ant(6)-Ib, are located within a transferable pathogenicity island in Campylobacter fetus subsp. fetus

New tetracycline and streptomycin resistance genes, tet(44) and ant(6)-Ib, were identified in Campylobacter fetus subsp. fetus within a transferable pathogenicity island that is typically unique to Campylobacter fetus subsp. venerealis. The 640-amino-acid tetracycline resistance determinant, Tet 44, belongs to a class of proteins that confers resistance to tetracycline and minocycline by ribosomal protection. The 286-amino-acid streptomycin resistance determinant, ANT(6)-Ib, belongs to a family of aminoglycoside nucleotidyltransferases. The resistance phenotypes were demonstrated by gene inactivation and expression.

Campylobacter bacteremia: clinical features and factors associated with fatal outcome

BACKGROUND

Campylobacter bacteremia is uncommon. The influence of underlying conditions and of the impact of antibiotics on infection outcome are not known.

METHODS

From January 2000 through December 2004, 183 episodes of Campylobacter bacteremia were identified in 23 hospitals in the Paris, France, area. The medical records were reviewed. Characteristics of bacteremia due to Campylobacter fetus and to other Campylobacter species were compared. Logistic regression analysis was performed to identify risk factors for fatal outcome within 30 days.

RESULTS

Most affected patients were elderly or immunocompromised. C. fetus was the most commonly identified species (in 53% of patients). The main underlying conditions were liver disease (39%) and cancer (38%). The main clinical manifestations were diarrhea (33%) and skin infection (16%). Twenty-seven patients (15%) died within 30 days. Compared with patients with bacteremia due to other Campylobacter species, patients with C. fetus bacteremia were older (mean age, 69.5 years vs. 55.6 years; P = .001) and were more likely to have cellulitis (19% vs. 7%; P = .03), endovascular infection (13% vs. 1%; P = .007), or infection associated with a medical device (7% vs. 0%; P = .02). Independent risk factors for death were cancer (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.2-20.8) and asymptomatic infection (OR, 6.7; 95% CI, 1.5-29.4) for C. fetus bacteremia, the absence of prescription of appropriate antibiotics (OR, 12.2; 95% CI, 0.9-157.5), and prescription of third-generation cephalosporins (OR, 10.2; 95% CI, 1.9-53.7) for bacteremia caused by other species.

CONCLUSIONS

Campylobacter bacteremia occurs mainly in immunocompromised patients. Clinical features and risk factors of death differ by infection species.

Campylobacter fetus bloodstream infection: risk factors and clinical features

In this paper, we report 21 cases of Campylobacter fetus bloodstream infection observed in our institution over a 9-year period. The median age of the patients was 78 years. Most of them (62%) had a significant underlying disease, such as diabetes, immunodeficiency or cardiovascular disease. The main clinical features were fever with (62% of cases) or without (38%) extra-intestinal symptoms. These included mycotic aneurysm of the abdominal aorta (24%) and cellulitis (19%). Antibiotic treatment was mainly based on amoxicilline-clavulanate (57%) or imipenem (21%), for a median duration of 28 days. A favourable outcome was observed in 72% of cases. Death directly attributable to infection was observed for three patients, due to the rupture of an infected aneurysm or relapsing bloodstream infection with septic shock. All patients initially treated with imipenem had a favourable outcome. This report adds evidence that C. fetus bloodstream infection should be suspected in elderly patients with fever, immunodeficiency and cardiovascular damages. Imipenem seems to be the most active drug, especially in severe cases.

Identification of putative zinc hydrolase genes of the metallo-beta-lactamase superfamily from Campylobacter jejuni

DNA fragments encoding two putative zinc-dependent hydrolases, designated GLX2-1 and GLX2-2, from a clinical isolate of Campylobacter jejuni, strain 012, were cloned and sequenced. GLX2-1 was encoded by a sequence of 798 bp and GLX2-2 by a sequence of 597 bp. The amino acid sequences deduced from C. jejuni DNA showed 99% and 100% identity, respectively, to putative zinc hydrolases reported from C. jejuni ATCC strain 11168, and also shared identity (28-43%) with several hypothetical conserved proteins and known zinc-dependent hydrolases and metallo-beta-lactamase superfamily proteins. A strictly conserved motif, -H-X-H-X-D-, characteristic of the metallo-beta-lactamase superfamily of proteins, including class B metallo-beta-lactamases, was identified in both proteins. Other conserved metal-binding ligands, characteristic of the metallo-beta-lactamase superfamily of proteins, were also identified. Functional beta-lactamase could not be expressed in either Escherichia coli or Campylobacter coli transformed with C. jejuni hydrolase-containing plasmids, suggesting that they do not function as metallo-beta-lactamases, although structurally they are consistent with the zinc metallo-hydrolase family of the beta-lactamase fold.

Infection of the thyroid gland caused by Campylobacter fetus subsp. fetus

We report what we consider to be the first case of an abscess of the thyroid gland due to Campylobacter fetus subsp. fetus (C. fetus) in a patient suffering from hyperthyroidism. C. fetus is known as a rare and opportunistic pathogen in humans, causing a broad variety of systemic infections. Acquisition by humans is thought to occur through contact with animals or animal products and to start as a gastro-intestinal colonization. The detection of C. fetus in stool is challenging, since culture efforts are generally directed in order to fulfil growth requirements of C.jejuni, a much more common enteric pathogen. Detection of C. fetus in non-stool samples is even more challenging since routine culture doesn't imply prolonged incubation (>72h), selective media and microaerophilic conditions. It is therefore not unlikely that human infections caused by C. fetus occur more often than generally assumed.

Macrolide resistance in Campylobacter jejuni and Campylobacter coli: molecular mechanism and stability of the resistance phenotype

A collection of 23 macrolide-resistant Campylobacter isolates from different geographic areas was investigated to determine the mechanism and stability of macrolide resistance. The isolates were identified as Campylobacter jejuni or Campylobacter coli based on the results of the hippurate biochemical test in addition to five PCR-based genotypic methods. Three point mutations at two positions within the peptidyl transferase region in domain V of the 23S rRNA gene were identified. About 78% of the resistant isolates exhibited an A-->G transition at Escherichia coli equivalent base 2059 of the 23S rRNA gene. The isolates possessing this mutation showed a wide range of erythromycin and clarithromycin MICs. Thus, this mutation may incur a greater probability of treatment failure in populations infected by resistant Campylobacter isolates. Another macrolide-associated mutation (A-->C transversion), at E. coli equivalent base 2058, was detected in about 13% of the isolates. An A-->G transition at a position cognate with E. coli 23S rRNA base 2058, which is homologous to the A2142G mutation commonly described in Helicobacter pylori, was also identified in one of the C. jejuni isolates examined. In the majority of C. jejuni isolates, the mutations in the 23S rRNA gene were homozygous except in two cases where the mutation was found in two of the three copies of the target gene. Natural transformation demonstrated the transfer of the macrolide resistance phenotype from a resistant Campylobacter isolate to a susceptible Campylobacter isolate. Growth rates of the resulting transformants containing A-2058-->C or A-2059-->G mutations were similar to that of the parental isolate. The erythromycin resistance of six of seven representative isolates was found to be stable after successive subculturing in the absence of erythromycin selection pressure regardless of the resistance level, the position of the mutation, or the number of the mutated copies of the target gene. One C. jejuni isolate showing an A-2058-->G mutation, however, reverted to erythromycin and clarithromycin susceptibility after 55 subcultures on erythromycin-free medium. Investigation of ribosomal proteins L4 and L22 by sequence analysis in five representative isolates of C. jejuni and C. coli demonstrated no significant macrolide resistance-associated alterations in either the L4 or the L22 protein that might explain either macrolide resistance or enhancement of the resistance level.

A case of cellulitis complicating Campylobacter jejuni subspecies jejuni bacteremia and review of the literature

Infection with Campylobacter species is a predominant cause of food-borne gastroenteritis in the industrialized world. Bacteremia is detected in <1% of patients with diarrhea, mainly in immunocompromised hosts or those in the extremes of age. Reported here is the case of a 78-year-old, immunocompromised male patient with Campylobacter jejuni subsp. jejuni bacteremia complicated by cellulitis. The infection was characterized by a protracted course with several recurrences and refractoriness to multiple antibiotic regimens, responding only to a prolonged course of meropenem treatment. The frequency of cellulitis as reflected in previously reported series of Campylobacter bacteremia and the clinical characteristics of this difficult-to-treat infection are reviewed.

Epidemiology and antimicrobial susceptibilities of 111 Campylobacter fetus subsp. fetus strains isolated in Québec, Canada, from 1983 to 2000

The epidemiology and antimicrobial susceptibilities of 111 Campylobacter fetus subsp. fetus strains isolated from 103 patients from 1983 to 2000 in Québec, Canada, were determined. The median number of patients infected annually with this bacteria was seven, with an incidence of 0.1 per 100,000 population. The male-to-female ratio was 1.1 to 1.0. The patients originated from 13 of the 18 Québec socioeconomic regions. The age range of the patients was 6 months to 90 years old, 53% being > or = 70 years old and 2% being <20 years old. The isolation site was blood for 69% of the patients, stools for 20%, and other body fluids for 11% of them. Three patients suffered a relapse, with the same strain being isolated from the same site at different times as confirmed by pulse-field gel electrophoresis. All isolates were susceptible to ampicillin, gentamicin, meropenem, and imipenem, with 90% minimal inhibitory concentrations of 4, 1, 0.12, and < or = 0.06 microg/ml, respectively. Three percent and two percent of the strains were, respectively, resistant and intermediate to ciprofloxacin. Thirty-four percent of the strains were resistant to tetracycline. There was a nonsignificant increase in resistance to ciprofloxacin (P = 0.27) and to tetracycline (P = 0.65) in recent years. The percentages of intermediate and resistant MICs were, respectively, 12 and 1% for cefotaxime and 71 and 0% for erythromycin. All strains were beta-lactamase negative.

Campylobacter fetus pericarditis in a patient with beta-thalassemia: case report and review of the literature

A case of pericardial effusion due to Campylobacter fetus in a patient with thalassemia is presented. The patient failed to respond to ceftriaxone and clarithromycin despite in vitro susceptibility, but improved after pericardiectomy and ampicillin. Pericarditis due to C. fetus has rarely been reported. A high index of suspicion is essential to recognise this organism, because of its special microbiological characteristics.

Thermophilic multidrug-resistant Campylobacter fetus infection with hypersplenism and histiocytic phagocytosis in a patient with acquired immunodeficiency syndrome

We present a case report of a patient who had acquired immunodeficiency syndrome (AIDS) and Campylobacter fetus infection with a number of unusual clinical and microbiological features. The patient had prominent gastrointestinal symptoms, splenic infarction, splenomegaly with hypersplenism, and hemophagocytic histiocytosis in the spleen and lymph nodes; the organism displayed growth on Campy-selective blood agar, thermotolerance, and resistance to quinolones, piperacillin/tazobactam, ceftazidime, and erythromycin.