Campylobacter bacteremia: a rare and under-reported event?

Campylobacteriosis: A rising threat in foodborne illnesses

Campylobacteriosis is a foodborne illness that is contracted by eating contaminated food, particularly animal products like meat from diseased animals or corpses tainted with harmful germs. The epidemiology of campylobacteriosis varies significantly between low-, middle-, and high-income countries. Campylobacter has a complicated and poorly known survival strategy for getting past host barriers and causing sickness in humans. The adaptability of Campylobacter to unfavorable environments and the host's immune system seems to be one of the most crucial elements of intestinal colonization. A Campylobacter infection may result in fever, nausea, vomiting, and mild to severe bloody diarrhea in humans. Effective and rapid diagnosis of Campylobacter species infections in animal hosts is essential for both individual treatment and disease management at the farm level. According to the most recent meta-analysis research, the main risk factor for campylobacteriosis is travel, which is followed by eating undercooked chicken, being exposed to the environment, and coming into close contact with livestock. Campylobacter jejuni, and occasionally Campylobacter coli, are the primary causes of Campylobacter gastroenteritis, the most significant Campylobacter infection in humans for public health. The best antibiotic medications for eradicating and decreasing Campylobacter in feces are erythromycin, clarithromycin, or azithromycin. The best strategy to reduce the number of human infections caused by Campylobacter is to restrict the amount of contamination of the poultry flock and its products, even if the majority of infections are contracted through handling or ingestion of chicken.

A Case of Co-infection Due to Shigella flexneri Colitis Resulting in Bacillus Septic Shock in an Immunocompetent Patient

Shigella flexneri (S. flexneri) is a facultatively anaerobic gram-negative bacterium that is a member of Enterobacteriaceae. The bacterium has been known to cause mild symptoms, such as diarrhea, to more severe diseases such as hemorrhagic colitis. Fortunately, such instances of severe diseases are rare. Nevertheless, even though S. flexneri is a more benign bacterium of the Shigella genus when compared to Shigella dysenteriae, this doesn't mean that it should be neglected. In fact, the ability of this microorganism to cause inflammation of the colon or colitis and disrupt tissue architecture can allow other organisms that would otherwise be benign to cause severe complications, hence allowing said organisms to be opportunistic. Here, we would like to present a case of S. flexneri colitis resulting in bacillus bacteremia and eventually causing an inappropriate physiological host response leading to hypotension, systematic organ failure, etc., also known as septic shock. The pathogenesis and treatment of this patient will also be discussed.

A decade of Campylobacter and Campylobacter bacteraemias in a district general hospital and the surrounding London and South East region, England

BACKGROUND

Campylobacter bacteraemia is a rare complication of the most common bacterial gastrointestinal infection but is associated with significant morbidity and mortality. There is limited data describing current trends in surveillance and antimicrobial resistance for the Campylobacter strains involved. At the Epsom and St Helier's University Hospital (ESTH), we noted a marked increase in Campylobacter bacteraemia infections in 2021.

METHODS

We extracted Campylobacter reports using the UK Health Security Agency's (UKHSA) Second Generation Surveillance System (laboratory reporting system) between 1st January 2012 and 31st December 2021. We reviewed patient records of patients with Campylobacter bacteraemia for details including presentation, past medical history, duration of hospital stay, and antibiotic use.

RESULTS

Between 2012 and 2021, ESTH reported a total of 34 cases of Campylobacter bacteraemia. In 2021, the estimated incidence was 6.8 cases per 100,000 population and in the surrounding area, the incidence was 0.4 per 100,000 population. The incidence rate of Campylobacter bacteraemia in London and the South East region was significantly lower than ESTH (RR = 0.17, p < 0.0001). Campylobacter bacteraemia cases at ESTH reported a high number of co-morbidities (average number of comorbidities = 2.3) and had a duration of stay in hospital of a median of 7 days (IQR = 4-10 days). Campylobacter jejuni was the most commonly reported species for stool and blood Campylobacter in ESTH, London, and South East England.

CONCLUSION

Campylobacter bacteraemia reports at ESTH were significantly (p < 0.001) higher than the surrounding London and South East region. While no common cause for the exceedance of Campylobacter bacteraemia has been identified, common risk factors for Campylobacter bacteraemia infection include underlying health conditions, being older, and male.

Ceftriaxone Resistance in Campylobacter Gastroenteritis

Annually, millions of people worldwide are exposed to Campylobacter, a species of bacteria that commonly causes gastroenteritis and in cases of immunocompromised individuals, can also lead to life-threatening complications. After stool cultures are obtained, the usual treatment for infectious diarrhea involves metronidazole and quinolones such as ciprofloxacin or levofloxacin. Quinolones are a family of broad-spectrum antibiotics known to be effective against various gram-negative infections that also include Campylobacter jejuni (C. jejuni). However, due to adverse side effects and bacterial resistance risks that may exist with medication use, they are no longer used as a first line. Our patient, initially treated with ceftriaxone for symptoms resembling bacterial meningitis, pneumonia, and infectious diarrhea, showed minimal to no improvement. Subsequent cerebral spinal fluid (CSF) ruled out meningitis while stool studies confirmed C. jejuni as the causative agent. A switch to levofloxacin resulted in a noticeable improvement in the patient's condition. This case emphasizes the importance of considering changes in antibiotic regimen from ceftriaxone to quinolones when faced with persistent infectious diarrhea, due to the high prevalence of ceftriaxone resistance in C. jejuni infections.

Clinical characteristics of Campylobacter bacteremia: a multicenter retrospective study

Campylobacter species are the pathogens of the intestinal tract, which infrequently cause bacteremia. To reveal the clinical characteristics of Campylobacter bacteremia, we performed a retrospective, multicenter study. Patients diagnosed with Campylobacter bacteremia in three general hospitals in western Japan between 2011 and 2021 were included in the study. Clinical, microbiological, and prognostic data of the patients were obtained from medical records. We stratified the cases into the gastroenteritis (GE) and fever predominant (FP) types by focusing on the presence of gastrointestinal symptoms. Thirty-nine patients (24 men and 15 women) were included, with a median age of 57 years and bimodal distribution between those in their 20 s and the elderly. The proportion of GE and FP types were 21 (53.8%) and 18 (46.2%), respectively. Comparing these two groups, there was no significant difference in patient backgrounds in terms of sex, age, and underlying diseases. Campylobacter jejuni was exclusively identified in the GE type (19 cases, 90.5%), although other species such as Campylobacter fetus and Campylobacter coli were isolated in the FP type as well. Patients with the FP type underwent intravenous antibiotic therapy more frequently (47.6% vs. 88.9%), and their treatment (median: 5 days vs. 13 days) and hospitalization (median: 7 days vs. 21 days) periods were significantly longer. None of the patients died during the hospitalization. In summary, we found that nearly half of the patients with Campylobacter bacteremia presented with fever as a predominant manifestation without gastroenteritis symptoms.

Campylobacter coli bacteremia associated with diarrhea

Campylobacter coli (C. coli) is a gram negative, non-spore forming, mobile, curved, or spiral-shaped rod organisms and one of the most common gastrointestinal human pathogens. Campylobacter very rarely causes bacteremia. However, there are reports of bloodstream infection of C. coli and most of the Campylobacterbacteremia have been found among immunocompromised patients. In this study, a case of C. coli blood stream infection that was associated with diarrhea in an immunocompetent patient.

Campylobacter jejuni subdural hygroma infection in a 2-year old boy: case report and a brief literature review

Background

Campylobacter jejuni is a common cause of acute gastroenteritis, but central nervous system infections are rare manifestations of Campylobacter infection. Therefore, C. jejuni trauma-related subdural hygroma infection in children is poorly described in the literature.

Case presentation

We described a 2-year old boy with lobar holoprosencephaly presenting with subdural hygroma following head trauma. C. jejuni infection was confirmed from a subdural hygroma sample by culture as well as by DNA sequencing of a broad range 16S rDNA PCR product. Cerebrospinal fluid from the ventriculoperitoneal shunt remained sterile. Combined neurosurgical and antimicrobial treatment led to complete recovery. Review of the literature showed that the most common manifestation of Campylobacter central nervous system infection is meningitis, mostly in neonates, and subdural hygroma infection was described for only one case.

Conclusions

Subdural hygroma infection caused by C. jejuni is a rare clinical condition in children. Molecular methods represent an important tool for the detection of rare or unexpected pathogens. No standard recommendations for antimicrobial treatment of C. jejuni subdural space infection in children are available, but meropenem treatment combined with surgery seems to be an effective approach.

Concurrence of imatinib-induced massive pleural/pericardial effusion and Campylobacter bacteremia in an adolescent with chronic myeloid leukemia

Imatinib is a crucial therapeutic strategy against chronic myeloid leukemia. Though superficial edema is a common adverse effect of imatinib, massive fluid retention is rarely reported. Here, we report the case of an adolescent who had tolerated imatinib for a long time, and then presented with massive pleural/pericardial effusion during an episode of Campylobacter jejuni bacteremia. A stepwise and comprehensive survey excluded all other plausible causes of disease. The Naranjo scale was used to assess the probability of an adverse effect of medication, and the score turned out to be 9, indicating severe fluid retention to be a definite reaction to imatinib. Drug discontinuation, antibiotic administration, and invasive procedures improved this condition. After this episode, the patient could tolerate imatinib again, illustrating the transient and reversible nature of this reaction. Since prolonged imatinib usage is crucial for chronic myeloid leukemia control, alertness to drug-related adverse effects is recommended, even if the subject has previously shown a good tolerance to the drug due to various physical conditions, especially physiological stressors, like infection or inflammation.

Bacteraemia, antimicrobial susceptibility and treatment among Campylobacter-associated hospitalisations in the Australian Capital Territory: a review

BACKGROUND

Campylobacter spp. cause mostly self-limiting enterocolitis, although a significant proportion of cases require hospitalisation highlighting potential for severe disease. Among people admitted, blood culture specimens are frequently collected and antibiotic treatment is initiated. We sought to understand clinical and host factors associated with bacteraemia, antibiotic treatment and isolate non-susceptibility among Campylobacter-associated hospitalisations.

METHODS

Using linked hospital microbiology and administrative data we identified and reviewed Campylobacter-associated hospitalisations between 2004 and 2013. We calculated population-level incidence for Campylobacter bacteraemia and used logistic regression to examine factors associated with bacteraemia, antibiotic treatment and isolate non-susceptibility among Campylobacter-associated hospitalisations.

RESULTS

Among 685 Campylobacter-associated hospitalisations, we identified 25 admissions for bacteraemia, an estimated incidence of 0.71 cases per 100,000 population per year. Around half of hospitalisations (333/685) had blood culturing performed. Factors associated with bacteraemia included underlying liver disease (aOR 48.89, 95% CI 7.03-340.22, p < 0.001), Haematology unit admission (aOR 14.67, 95% CI 2.99-72.07, p = 0.001) and age 70-79 years (aOR 4.93, 95% CI 1.57-15.49). Approximately one-third (219/685) of admissions received antibiotics with treatment rates increasing significantly over time (p < 0.05). Factors associated with antibiotic treatment included Gastroenterology unit admission (aOR 3.75, 95% CI 1.95-7.20, p < 0.001), having blood cultures taken (aOR 2.76, 95% CI 1.79-4.26, p < 0.001) and age 40-49 years (aOR 2.34, 95% CI 1.14-4.79, p = 0.02). Non-susceptibility of isolates to standard antimicrobials increased significantly over time (p = 0.01) and was associated with overseas travel (aOR 11.80 95% CI 3.18-43.83, p < 0.001) and negatively associated with tachycardia (aOR 0.48, 95%CI 0.26-0.88, p = 0.02), suggesting a healthy traveller effect.

CONCLUSIONS

Campylobacter infections result in considerable hospital burden. Among those admitted to hospital, an interplay of factors involving clinical presentation, presence of underlying comorbidities, complications and increasing age influence how a case is investigated and managed.

Meningitis caused by Campylobacter jejuni: a case presentation and literature review

Objectives: Campylobacter jejuni is one of the most common causative agents of gastroenteritis; however C. jejuni meningitis is rarely described. Therefore, little is known about its epidemiology, clinical presentation, diagnostic methods, treatment, and outcomes.Methods: In this paper, we report a case of an adult patient with C. jejuni meningitis. In addition, we reviewed 16 cases of C. jejuni published since 1980.Results: We described a 62-year-old immunocompromised patient with meningitis and gastroenteritis in whom C. jejuni was rapidly detected in cerebrospinal fluid (CSF) using 16S rDNA, while blood culture yielded the same pathogen with 48 h delay. Following 21 day-long treatment with meropenem, our patient fully recovered. Literature review revealed that C. jejuni meningitis is mainly described in newborns and adults with central nervous system comorbidities and it is most frequently detected by bacterial cultures.Conclusion: There are no clear recommendations for antimicrobial treatment of C. jejuni meningitis, but meropenem seems to be a safe and effective choice. High hopes are placed in new, broad-range culture-independent molecular methods that enable rapid pathogen detection, even in case of negative cultures.

Campylobacter-associated hospitalisations in an Australian provincial setting

BACKGROUND

Campylobacter spp. infections are a globally important cause of enterocolitis, causing substantial morbidity. Capturing accurate information on hospitalisations is challenging and limited population-level data exist to describe the clinico-epidemiological characteristics of hospitalised cases.

METHODS

Hospital administrative and laboratory datasets were linked to identify Campylobacter-associated hospitalisations between 2004 and 2013. Accuracy of morbidity coding was assessed using laboratory diagnosis as a gold standard, with health department surveillance data used to calculate population-based rates. Additional patient-level data were collected via review of medical records. Descriptive statistics were used to assess changes in rates and proportions and to assess relationships between key variables including age, length of stay, comorbidity and complications.

RESULTS

In total 685 Campylobacter-associated hospital admissions were identified, with the sensitivity of morbidity coding 52.8% (95% CI 48.9-56.7%). The mean annual rate of hospitalisation was 13.6%. Hospitalisation rates were higher for females across most age-groups, while for both genders marked increases were observed for those aged ≥60 years. Median admission age was 39.5 years, with an average length of stay of 3.5 days. Comorbidities were present in 34.5% (237/685) of admissions, with these patients more likely to develop electrolyte disturbances, hypotension, renal impairment or acute confusion (all p < 0.001). Bacteraemia and acute kidney injury were observed in 4.1% (28/685) and 3.6% (23/685) of admissions, respectively. Inpatient mortality was low (0.15%).

CONCLUSION

Under reporting of Campylobacter-associated hospitalisations is substantial but can be improved through data linkage. We observed demographic differences among those hospitalised but further work is needed to determine risk factors and predictors for hospitalisation.

The Prevalence of Campylobacter in Live Cattle, Turkey, Chicken, and Swine in the United States and Canada: A Systematic Review and Meta-Analysis

Campylobacter cause gastroenteritis in humans and may be shed in the feces of livestock and poultry species, including cattle, chicken, turkey, and swine. However, a synthesis of the prevalence on farms in the United States and Canada is currently lacking. Thus, our objective was to conduct a systematic review and meta-analysis to estimate the prevalence of Campylobacter coli, Campylobacter jejuni, and Campylobacter spp. on livestock and poultry farms operated under commercial conditions in the United States and Canada. The relevant literature was identified and examined for eligibility based on a priori inclusion and exclusion criteria. Relevant data were extracted, and a meta-analysis was performed. The data were transformed using the Freeman-Tukey arcsine transformation to stabilize the variance. A separate meta-analysis was performed for each animal species, level of sampling (individual versus pooled), and species of Campylobacter, for a total of 29 meta-analyses. C. jejuni and Campylobacter spp. were present in all livestock and poultry species of interest, whereas C. coli was found in all species of interest with the exception of chickens. Furthermore, substantial heterogeneity was observed in most meta-analyses. In an attempt to account for this, subgroup analyses were performed on potential moderators. However, with the exception of beef cattle, where studies in feedlot cattle reported a consistently higher prevalence compared with adult cattle on pasture, significant heterogeneity remained in the majority of meta-analyses after accounting for potential moderators. The results of this review can be used to inform future risk assessment, consumer and producer awareness, and resource allocation, and identify gaps for future research.

Relevance of anaerobic bacteremia in adult patients: A never-ending story?

Obligate anaerobic bacteria are considered important constituents of the microbiota of humans; in addition, they are also important etiological agents in some focal or invasive infections and bacteremia with a high level of mortality. Conflicting data have accumulated over the last decades regarding the extent in which these pathogens play an intrinsic role in bloodstream infections. Clinical characteristics of anaerobic bloodstream infections do not differ from bacteremia caused by other pathogens, but due to their longer generation time and rigorous growth requirements, it usually takes longer to establish the etiological diagnosis. The introduction of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) has represented a technological revolution in microbiological diagnostics, which has allowed for the fast, accurate and reliable identification of anaerobic bacteria at a low sample cost. The purpose of this review article is to summarize the currently available literature data on the prevalence of anaerobic bacteremia in adults for physicians and clinical microbiologists and to shed some light on the complexity of this topic nowadays.

Source attribution of Campylobacter jejuni shows variable importance of chicken and ruminants reservoirs in non-invasive and invasive French clinical isolates

Campylobacter jejuni is the most common cause of bacterial gastroenteritis worldwide. Mainly isolated from stool samples, C. jejuni can also become invasive. C. jejuni belongs to the commensal microbiota of a number of hosts, and infection by this bacterium can sometimes be traced back to exposure to a specific source. Here we genome sequenced 200 clinical isolates (2010–2016) and analyzed them with 701 isolate genomes from human infection, chicken, ruminants and the environment to examine the relative contribution of different reservoirs to non-invasive and invasive infection in France. Host-segregating genetic markers that can discriminate C. jejuni source were used with STRUCTURE software to probabilistically attribute the source of clinical strains. A self-attribution correction step, based upon the accuracy of source apportionment within each potential reservoir, improved attribution accuracy of clinical strains and suggested an important role for ruminant reservoirs in non-invasive infection and a potentially increased contribution of chicken as a source of invasive isolates. Structured sampling of Campylobacter in the clinic and from potential reservoirs provided evidence for variation in the contribution of different infection sources over time and an important role for non-poultry reservoirs in France. This provides a basis for ongoing genomic epidemiology surveillance and targeted interventions.

Reaction of antibodies to Campylobacter jejuni and cytolethal distending toxin B with tissues and food antigens

BACKGROUND

The bacteria Campylobacter jejuni (C. jejuni) is commonly associated with Guillane-Barré syndrome (GBS) and irritable bowel syndrome (IBS), but studies have also linked it with Miller Fisher syndrome, reactive arthritis and other disorders, some of which are autoimmune. It is possible that C. jejuni and its toxins may be cross-reactive with some human tissues and food antigens, potentially leading to autoimmune responses.

AIM

To measure the immune reactivity of C. jejuni and C. jejuni cytolethal distending toxin (Cdt) antibodies with tissue and food antigens to examine their role in autoimmunities.

METHODS

Using enzyme-linked immunosorbent assay (ELISA) methodology, specific antibodies made against C. jejuni and C. jejuni Cdt were applied to a variety of microwell plates coated with 45 tissues and 180 food antigens. The resulting immunoreactivities were compared to reactions with control wells coated with human serum albumin (HSA) which were used as negative controls and with wells coated with C. jejuni lysate or C. jejuni Cdt which served as positive controls.

RESULTS

At 3 SD above the mean of control wells coated with HSA or 0.41 OD, the mouse monoclonal antibody made against C. jejuni showed moderate to high reactions with zonulin, somatotropin, acetylcholine receptor, β-amyloid and presenilin. This immune reaction was low with an additional 25 tissue antigens including asialoganglioside, and the same antibody did not react at all with another 15 tissue antigens. Examining the reaction between C. jejuni antibody and 180 food antigens, we found insignificant reactions with 163 foods but low to high immune reactions with 17 food antigens. Similarly, we examined the reaction of C. jejuni Cdt with the same tissues and food antigens. The strongest reactions were observed with zonulin, intrinsic factor and somatotropin. The reaction was moderate with 9 different tissue antigens including thyroid peroxidase, and reaction was low with another 10 different antigens, including neuronal antigens. The reaction of C. jejuni Cdt antibody with an additional 23 tissue antigens was insignificant. Regarding the reaction of C. jejuni Cdt antibody with different food antigens, 160 out of 180 foods showed insignificant reactions, while 20 foods showed reactions ranging from low to high.

CONCLUSION

Our findings indicate that C. jejuni and its Cdt may play a role in inflammation and autoimmunities beyond the gut.

Genomic correlates of extraintestinal infection are linked with changes in cell morphology in Campylobacter jejuni

Campylobacter jejuni is the most common cause of bacterial diarrheal disease in the world. Clinical outcomes of infection can range from asymptomatic infection to life-threatening extraintestinal infections. This variability in outcomes for infected patients has raised questions as to whether genetic differences between C. jejuni isolates contribute to their likelihood of causing severe disease. In this study, we compare the genomes of ten C. jejuni isolates that were implicated in extraintestinal infections with reference gastrointestinal isolates, in order to identify unusual patterns of sequence variation associated with infection outcome. We identified a collection of genes that display a higher burden of uncommon mutations in invasive isolates compared with gastrointestinal close relatives, including some that have been previously linked to virulence and invasiveness in C. jejuni. Among the top genes identified were mreB and pgp1, which are both involved in determining cell shape. Electron microscopy confirmed morphological differences in isolates carrying unusual sequence variants of these genes, indicating a possible relationship between extraintestinal infection and changes in cell morphology.

Clinical characteristics of Campylobacter enteritis after pediatric renal transplantation: A retrospective analysis from single center

BACKGROUND

There are few reports of patients with Campylobacter enteritis after renal transplantation, and only a few case reports of bacteremia have been published. Although antibiotic therapy for 3-5 days has been recommended for immunocompromised patients, the optimal treatment for Campylobacter enteritis after renal transplantation has not been established. This study aimed to clarify the clinical characteristics and treatment outcomes of Campylobacter enteritis after pediatric renal transplantation.

METHODS

This retrospective study included patients who underwent pediatric renal transplantation and were found to have Campylobacter species in stool cultures between January 2014 and May 2017.

RESULTS

This study included eight patients who underwent pediatric renal transplantation. The median age at the time of renal transplantation was 14 years, and the median period between transplantation and disease occurrence was 4.6 years. Clinical symptoms were abdominal pain for eight patients, diarrhea for eight patients, fever for seven patients, vomiting for three patients, and headache for three patients. Campylobacter jejuni was isolated from the stool cultures of all patients. The median administration period of antibiotics as initial therapy was 7 days (range, 4-11 days). However, clinical relapse was observed in four patients after completing antibiotic therapy. Patients who experienced clinical relapse required a second course of antibiotic therapy for a median duration of 7 days (range, 5-10 days).

CONCLUSIONS

Patients with Campylobacter enteritis after pediatric renal transplantation are at high risk for clinical relapse and may require a longer duration of antibiotic therapy than that generally described.

Campylobacter coli meningitis in a 57-year-old patient

Campylobacter coli is a major pathogen rarely responsible for extra-intestinal infections. We report a case of Campylobacter coli bacteremia and meningitis in a 57-year-old immunocompetent Belgian man. The strain, isolated from cerebrospinal fluid, belonged to the unusual sequence type 8418 (ST8418). The patient fully recovered after meropenem treatment.

Emergence of Carbapenem Non-susceptible Campylobacter coli after Long-term Treatment against Recurrent Bacteremia in a Patient with X-linked Agammaglobulinemia

We herein report a case of recurrent Campylobacter coli bacteremia in a 37-year-old Japanese man with X-linked agammaglobulinemia (XLA). The patient experienced seven episodes of C. coli bacteremia over one year, with an erythematous rash intermittently emerged on the lower limbs. Although hospitalization for intravenous treatment was repeatedly recommended, he obstinately declined it. Following long-term oral antibiotic treatment with tebipenem and faropenem for the persistent infection, C. coli showed elevated minimum inhibitory concentrations to meropenem, a key drug for severe campylobacteriosis. Physicians should note that the overuse of antibiotics can lead to the emergence of carbapenem-non-susceptible Campylobacter strains.

Convergent Amino Acid Signatures in Polyphyletic Campylobacter jejuni Subpopulations Suggest Human Niche Tropism

Human infection with the gastrointestinal pathogen Campylobacter jejuni is dependent upon the opportunity for zoonotic transmission and the ability of strains to colonize the human host. Certain lineages of this diverse organism are more common in human infection but the factors underlying this overrepresentation are not fully understood. We analyzed 601 isolate genomes from agricultural animals and human clinical cases, including isolates from the multihost (ecological generalist) ST-21 and ST-45 clonal complexes (CCs). Combined nucleotide and amino acid sequence analysis identified 12 human-only amino acid KPAX clusters among polyphyletic lineages within the common disease causing CC21 group isolates, with no such clusters among CC45 isolates. Isolate sequence types within human-only CC21 group KPAX clusters have been sampled from other hosts, including poultry, so rather than representing unsampled reservoir hosts, the increase in relative frequency in human infection potentially reflects a genetic bottleneck at the point of human infection. Consistent with this, sequence enrichment analysis identified nucleotide variation in genes with putative functions related to human colonization and pathogenesis, in human-only clusters. Furthermore, the tight clustering and polyphyly of human-only lineage clusters within a single CC suggest the repeated evolution of human association through acquisition of genetic elements within this complex. Taken together, combined nucleotide and amino acid analysis of large isolate collections may provide clues about human niche tropism and the nature of the forces that promote the emergence of clinically important C. jejuni lineages.

Inquiring into the Gaps of Campylobacter Surveillance Methods

Campylobacter is one of the most common pathogen-related causes of diarrheal illnesses globally and has been recognized as a significant factor of human disease for more than three decades. Molecular typing techniques and their combinations have allowed for species identification among members of the Campylobacter genus with good resolution, but the same tools usually fail to proceed to subtyping of closely related species due to high sequence similarity. This problem is exacerbated by the demanding conditions for isolation and detection from the human, animal or water samples as well as due to the difficulties during laboratory maintenance and long-term storage of the isolates. In an effort to define the ideal typing tool, we underline the strengths and limitations of the typing methodologies currently used to map the broad epidemiologic profile of campylobacteriosis in public health and outbreak investigations. The application of both the old and the new molecular typing tools is discussed and an indirect comparison is presented among the preferred techniques used in current research methodology.

Campylobacter bacteremia in London: A 44-year single-center study

PURPOSE

Campylobacter species are a well-recognized but rare cause of bloodstream infection.

METHODS

Here we reviewed 41 cases of Campylobacter bloodstream infection occurring at a single center in London over 44years, comprising 0.2% of all recorded episodes during this time period.

RESULTS

Patients had a mean age of 46years and, contrasting with previous reports, nearly 50% of our patients did not have significant comorbidities. Ciprofloxacin resistance increased over the study period with 35% of isolates overall being resistant compared with only 3% exhibiting macrolide resistance. Despite a minority of patients receiving appropriate empirical antibiotic therapy, overall mortality was only 7%.

CONCLUSION

Campylobacter bacteremia remains a rare but significant cause of morbidity with a low associated mortality. Underlying immunosuppressive conditions are common but by no means universal. In our setting, macrolides would be favored as empirical agents to treat suspected Campylobacter enteritis, including cases with associated bacteremia.

Accessory genetic content in Campylobacter jejuni ST21CC isolates from feces and blood

Campylobacter jejuni is an important foodborne pathogen and the most commonly reported bacterial cause of gastroenteritis. C. jejuni is occasionally found in blood, although mechanisms important for invasiveness have remained unclear. C. jejuni is divided into many different lineages, of which the ST21 clonal complex (CC) is widely distributed. Here, we performed comparative genomic and in vitro analyses on 17C. jejuni ST21CC strains derived from human blood and feces in order to identify features associated with isolation site. The ST21CC lineage is divided into two large groups; centered around ST-21 and ST-50. Our clinical strains, typed as ST-50, showed further microevolution into two distinct clusters. These clusters were distinguished by major differences in their capsule loci and the distribution of accessory genetic content, including C. jejuni integrated elements (CJIEs) and plasmids. Accessory genetic content was more common among fecal than blood strains, whereas blood strains contained a hybrid capsule locus which partially consisted of C. jejuni subsp. doylei-like content. In vitro infection assays with human colon cell lines did not show significant differences in adherence and invasion between the blood and fecal strains. Our results showed that CJIEs and plasmid derived genetic material were less common among blood isolates than fecal isolates; in contrast, hybrid capsule loci, especially those containing C. jejuni subsp. doylei-like gene content, were found among many isolates derived from blood. The role of these findings requires more detailed investigation.

Simplified antibiotic regimens for treatment of clinical severe infection in the outpatient setting when referral is not possible for young infants in Pakistan (Simplified Antibiotic Therapy Trial [SATT]): a randomised, open-label, equivalence trial

BACKGROUND

Parenteral antibiotic therapy for young infants (aged 0-59 days) with suspected sepsis is sometimes not available or feasible in countries with high neonatal mortality. Outpatient treatment could save lives in such settings. We aimed to assess the equivalence of two simplified antibiotic regimens, comprising fewer injections and oral rather than parenteral administration, compared with a reference treatment for young infants with clinical severe infection.

METHODS

We undertook the Simplified Antibiotic Therapy Trial (SATT), a three-arm, randomised, open-label, equivalence trial in five communities in Karachi, Pakistan. We enrolled young infants (aged 0-59 days) who either presented at a primary health-care clinic or were identified by a community health worker with signs of clinical severe infection. We included infants who were not critically ill and whose family refused admission. We randomly assigned infants to either intramuscular procaine benzylpenicillin and gentamicin once a day for 7 days (reference); oral amoxicillin twice daily and intramuscular gentamicin once a day for 7 days; or intramuscular procaine benzylpenicillin and gentamicin once a day for 2 days followed by oral amoxicillin twice daily for 5 days. The primary outcome was treatment failure within 7 days of enrolment and the primary analysis was per protocol. We judged experimental treatments as efficacious as the reference if the upper bound of the 95% CI for the difference in treatment failure was less than 5·0. This trial is registered at ClinicalTrials.gov, number NCT01027429.

FINDINGS

Between Jan 1, 2010, and Dec 26, 2013, 2780 infants were deemed eligible for the trial, of whom 2453 (88%) were enrolled. Because of inadequate clinical follow-up or treatment adherence, 2251 infants were included in the per-protocol analysis. 820 infants (747 per protocol) were assigned the reference treatment of procaine benzylpenicillin and gentamicin, 816 (751 per protocol) were allocated amoxicillin and gentamicin, and 817 (753 per protocol) were assigned procaine benzylpenicillin, gentamicin, and amoxicillin. Treatment failure within 7 days of enrolment was reported in 90 (12%) infants who received procaine benzylpenicillin and gentamicin (reference), 76 (10%) of those given amoxicillin and gentamicin (risk difference with reference -1·9, 95% CI -5·1 to 1·3), and 99 (13%) of those treated with procaine benzylpenicillin, gentamicin, and amoxicillin (risk difference with reference 1·1, -2·3 to 4·5).

INTERPRETATION

Two simplified antibiotic regimens requiring fewer injections are equivalent to a reference treatment for young infants with signs of clinical severe infection but without signs of critical illness. The use of these simplified regimens has the potential to increase access to treatment for sick young infants who cannot be referred to hospital.

FUNDING

The Saving Newborn Lives initiative of Save the Children, through support from the Bill & Melinda Gates, and by WHO and USAID.

Polyphosphate and associated enzymes as global regulators of stress response and virulence in Campylobacter jejuni

Campylobacter jejuni (C. jejuni), a Gram-negative microaerophilic bacterium, is a predominant cause of bacterial foodborne gastroenteritis in humans worldwide. Despite its importance as a major foodborne pathogen, our understanding of the molecular mechanisms underlying C. jejuni stress survival and pathogenesis is limited. Inorganic polyphosphate (poly P) has been shown to play significant roles in bacterial resistance to stress and virulence in many pathogenic bacteria. C. jejuni contains the complete repertoire of enzymes required for poly P metabolism. Recent work in our laboratory and others have demonstrated that poly P controls a plethora of C. jejuni properties that impact its ability to survive in the environment as well as to colonize/infect mammalian hosts. This review article summarizes the current literature on the role of poly P in C. jejuni stress survival and virulence and discusses on how poly P-related enzymes can be exploited for therapeutic/prevention purposes. Additionally, the review article identifies potential areas for future investigation that would enhance our understanding of the role of poly P in C. jejuni and other bacteria, which ultimately would facilitate design of effective therapeutic/preventive strategies to reduce not only the burden of C. jejuni-caused foodborne infections but also of other bacterial infections in humans.

[Invasive Campylobacter jejuni/coli Infections: 9 Case Reports at a Single Center between 2000 and 2015, and a Review of Literature Describing Japanese Patients]

There have been few coherent reports on extraintestinal infection or bacteremia caused by Campylobacter jejuni (C. jejuni) or C. coli in Japan. To clarify the clinical and microbiological characteristics of invasive infections caused by these two species, we retrospectively analyzed the records of patients from whom these pathogens had been isolated from sterile sites between 2000 and 2015. During this study period, we identified 9 patients. The clinical syndrome of all of these patients was bacteremia. Three patients had underlying diseases with both liver cirrhosis and malignant neoplasm, and all of these patients were aged 60 years or older. The remaining 6 patients were immunocompetent and younger than 40 years of age. All 9 patients had a fever of 38.5 degrees C or higher. The proportion of patients with gastrointestinal symptoms was lower for the 3 patients with underlying diseases, compared with the 6 patients without underlying diseases (1/3 cases vs, 4/6 cases). Of the 8 strains evaluated for antimicrobial susceptibility, all were susceptible to imipenem/cilastatin, kanamycin and erythromycin, and 2 were resistant to levofloxacin. Antimicrobial treatment was administered to 8 patients, but one spontaneously recovered without any treatment. We were able to follow the outcomes of 8 patients, and all of these patients completely recovered without relapses. We also reviewed 14 Japanese patients reported in the Japanese and English literature and found similar clinical features consisting of a high-grade fever and an association with underlying diseases and gastrointestinal symptoms. Of note, 3 agammaglobulinemic patients presented with bacteremia and extraintestinal infections and had multiple relapses. Based on the findings of our 9 cases and previous reports, the affected patients were divided into two groups according to clinical syndrome and therapeutic intervention. One group consisted of previously healthy children or young adults showing bacteremia. Most of them had enterocolitis complications but had a good prognosis. The other group consisted of patients with underlying diseases or elderly patients who presented with bacteremia alone or bacteremia with extraintestinal infections. The latter group, especially among those with humoral immunodeficiency, should be parentally treated with antimicrobial agents and requires careful monitoring for relapse. This is the largest case series study to examine invasive C. jejuni/coli infections in Japan, and it provides important epidemiological information on this rare infection.

Campylobacter jejuni-associated perimyocarditis: two case reports and review of the literature

Background

Campylobacter spp. are among the most common bacterial causes of gastroenteritis world-wide and mostly follow a benign course. We report two cases of Campylobacter jejuni-associated perimyocarditis, the first two simultaneous cases published to date and the third and fourth cases over all in Sweden, and a review of the literature.

Case presentation

A previously healthy 24-yo male (A) presented at the Emergency Department(ED) with recent onset of chest pain and a 3-day history of abdominal pain, fever and diarrhoea. The symptoms began within a few hours of returning from a tourist visit to a central European capital. Vital signs were stable, the Electrocardiogram(ECG) showed generalized ST-elevation, laboratory testing showed increased levels of C-reactive protein(CRP) and high-sensitive Troponin T(hsTnT). Transthoracic echocardiogram (TTE) was normal, stool cultures were positive for C Jejuni and blood cultures were negative. Two days after patient A was admitted to the ED his travel companion (B), also a previously healthy male (23-yo), presented at the same ED with almost identical symptoms: chest pain precipitated by a few days of abdominal pain, fever and diarrhoea. Patient B declared that he and patient A had ingested chicken prior to returning from their tourist trip. Laboratory tests showed elevated CRP and hsTnT but the ECG and TTE were normal. In both cases, the diagnosis of C jejuni-associated perimyocarditis was set based on the typical presentation and positive stool cultures with identical strains. Both patients were given antibiotics, rapidly improved and were fully recovered at 6-week follow up.

Conclusion

Perimyocarditis is a rare complication of C jejuni infections but should not be overlooked considering the risk of heart failure. With treatment, the prognosis of full recovery is good but several questions remain to be answered regarding the pathophysiology and the male preponderance of the condition.

Campylobacter jejuni Fatal Sepsis in a Patient with Non-Hodgkin's Lymphoma: Case Report and Literature Review of a Difficult Diagnosis

Campylobacter jejuni (C. jejuni) bacteremia is difficult to diagnose in individuals with hematological disorders undergoing chemotherapy. The cause can be attributed to the rarity of this infection, to the variable clinical presentation, and to the partial overlapping symptoms underlying the disease. Here, we report a case of a fatal sepsis caused by C. jejuni in a 76-year-old Caucasian man with non-Hodgkin’s lymphoma. After chemotherapeutic treatment, the patient experienced fever associated with severe neutropenia and thrombocytopenia without hemodynamic instability, abdominal pain, and diarrhea. The slow growth of C. jejuni in the blood culture systems and the difficulty in identifying it with conventional biochemical phenotyping methods contributed to the delay of administering a targeted antimicrobial treatment, leading to a fatal outcome. Early recognition and timely intervention are critical for the successful management of C. jejuni infection. Symptoms may be difficult to recognize in immunocompromised patients undergoing chemotherapy. Thus, it is important to increase physician awareness regarding the clinical manifestations of C. jejuni to improve therapeutic efficacy. Moreover, the use of more aggressive empirical antimicrobial treatments with aminoglycosides and/or carbapenems should be considered in immunosuppressed patients, in comparison to those currently indicated in the guidelines for cancer-related infections supporting the use of cephalosporins as monotherapy.

Epidemiology of Campylobacter jejuni infections in Sweden, November 2011-October 2012: is the severity of infection associated with C. jejuni sequence type?

BACKGROUND

Campylobacter jejuni is among the most frequent causes of bacterial gastroenteritis in Europe. Over 8,000 C. jejuni multilocus sequence typing sequence types (STs) have been described; ST-21 and ST-45 have been identified as the most frequent types in all human studies so far. In contrast to other STs, ST-22 has been associated with the Guillain-Barré syndrome and ST-677 was recently linked to severe systemic infections in Finland. We investigated risk factors associated with hospitalisation in individuals with C. jejuni infections acquired in Sweden.

METHODS

A total of 1,075 individuals with domestically acquired C. jejuni infection diagnosed between November 2011 and October 2012 in Sweden were included in this retrospective cohort study. Typing data for the isolates as well as clinical data including hospitalisation dates and diagnosis codes for individuals with C. jejuni infection were obtained. Factors associated with hospitalisation and length of hospitalisation were investigated by multivariable analysis.

RESULTS

A total of 289 individuals were hospitalised due to C. jejuni infection (26.8%); those with co-morbidities were over 14 times more likely to become hospitalised than those without (odds ratio [OR]: 14.39, 95% confidence interval [CI]: 6.84-30.26). Those with underlying co-morbidities were also hospitalised longer than those without (4.22 days vs. 2.86 days), although this was not statistically significant. C. jejuni ST-257 (OR: 2.38; CI: 1.08-5.23), but not ST-22 or ST-677, was significantly associated with hospitalisation.

CONCLUSION

ST-677 was not associated with increased hospitalisation or a longer hospital stay in our study whilst ST-257 was. However, individuals with C. jejuni infections were generally more frequently hospitalised than previously demonstrated; this requires further consideration including possible targeted interventions.

Comparative genomics and genome biology of invasive Campylobacter jejuni

Campylobacter jejuni is a major pathogen in bacterial gastroenteritis worldwide and can cause bacteremia in severe cases. C. jejuni is highly structured into clonal lineages of which the ST677CC lineage has been overrepresented among C. jejuni isolates derived from blood. In this study, we characterized the genomes of 31 C. jejuni blood isolates and 24 faecal isolates belonging to ST677CC in order to study the genome biology related to C. jejuni invasiveness. We combined the genome analyses with phenotypical evidence on serum resistance which was associated with phase variation of wcbK; a GDP-mannose 4,6-dehydratase involved in capsular biosynthesis. We also describe the finding of a Type III restriction-modification system unique to the ST-794 sublineage. However, features previously considered to be related to pathogenesis of C. jejuni were either absent or disrupted among our strains. Our results refine the role of capsule features associated with invasive disease and accentuate the possibility of methylation and restriction enzymes in the potential of C. jejuni to establish invasive infections. Our findings underline the importance of studying clinically relevant well-characterized bacterial strains in order to understand pathogenesis mechanisms important in human infections.

Milk Modulates Campylobacter Invasion into Caco-2 Intestinal Epithelial Cells

Raw milk is a recognized source of Campylobacter outbreaks, but pasteurization is an effective way to eliminate the causative agent of Campylobacteriosis. Whereas breastfeeding is protective against infectious diseases, consumption of formula milk is thought to be not. However, in relation to Campylobacter, such data is currently unavailable. Although both pasteurized and formula milk are pathogen free and prepared in a quality controlled manner, the effect they have on the virulence of Campylobacter species is unknown. Here, we studied the effect of cow, goat, horse, and formula milk on Campylobacter invasion into intestinal epithelial Caco-2 cells, a pathogenic feature of this bacterial species, using a gentamicin exclusion invasion assay. We found that all milk products modulated the invasion of Campylobacter species into the Caco-2 cells in a dose-dependent manner. Control experiments showed that the milks were not toxic for the Caco-2 cells and that the effect on invasion is caused by heat labile (e.g., milk proteins) or heat stable (e.g., sugar/lipids) components depending on the Campylobacter species studied. This in vitro study shows for the first time that pasteurized and formula milk affect the invasion of Campylobacter. We recommend a prospective study to examine whether pasteurized and formula milk affect Campylobacteriosis.

Global Epidemiology of Campylobacter Infection

Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection.

Are bacteriophage defence and virulence two sides of the same coin in Campylobacter jejuni?

The continuous battle for survival in the environment has led to the development or acquisition of sophisticated defence systems in bacteria. These defence systems have contributed to the survival of the bacterial species in the environment for millions of years. Some systems appear to have evolved in a number of pathogenic bacteria towards a role in virulence and host immune evasion. Recently, different bacterial cell envelope components from diverse bacterial species have been linked not only to bacteriophage defence, but also to virulence features. In the present review we focus specifically on the bacterial cell envelope-expressed sialic-acid-containing LOS (lipo-oligosaccharide) structures and Type II CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) genes that both occur in specific Gram-negative pathogens. In Campylobacter jejuni circumstantial evidence points at a potential intertwined dual function between sialylated LOS structures and subtype II-C CRISPR-Cas, i.e. in phage defence and virulence. In the present review we discuss whether a dual functionality of sialylated LOS and subtype II-C CRISPR-Cas is exclusive to C. jejuni only or could be more widespread within the group of Type II CRISPR-Cas-harbouring bacteria. We conclude from the literature that, at least in C. jejuni, circumstantial evidence exists for a complex intertwined dual functionality between sialylated LOS and Type II CRISPR-Cas, and that other bacteria show similar genomic signatures.

Microbiological food safety and a low-microbial diet to protect vulnerable people

Low-microbial diets are advised by many institutions for people with neutropenia resulting from treatment with immunosuppressive drugs or medical conditions that increase their susceptibility to foodborne disease. In this article, the main microbiological hazards associated with foods are outlined, and a low-microbial diet in which higher-risk foods are replaced by lower-risk foods is described.