Hiding in Plain Sight: Colonic Spirochetosis in Humans

Intestinal spirochetosis: four cases with different clinical presentations

We present 4 clinical cases of intestinal spirochetosis. The first one presents with chronic diarrhea, and spirochetes are detected in random biopsies. The second is homosexual, HIV+, presents rectal bleeding, colonoscopy shows a straight ulcer and spirochete biopsies show negative treponema PCR. The third was also homosexual, HIV+, asymptomatic, with a chance finding of spirochetosis. The last case is also a chance histological diagnosis in a patient with inactive ulcerative colitis without lesions. Intestinal spirochetosis appears to be transmitted sexually and by consumption of contaminated water. The majority are asymptomatic cases but could cause lesions including ulcerations and symptoms. Treatment is only recommended in symptomatic or immunosuppressed patients. It must be distinguished from lesions caused by Treponema pallidum.

Colonizing the Unlikely: Brachyspira in an Immunocompetent Patient

Chronic diarrhea is a common condition that medical professionals often encounter. We present an unusual case of chronic diarrhea in a relatively young, immunocompetent man that was attributed to Brachyspira. The patient's clinical presentation was not specific, and he underwent workup for common infectious, inflammatory, and autoimmune causes, all unrevealing. During colonoscopy, no abnormalities were detected; however, histopathology revealed the presence of Brachyspira. Following a course of metronidazole, the patient showed marked improvement in his diarrhea. It is worth noting that the patient's social history did not align with the established risk factors mentioned in the existing literature.

Clinical and Pathologic Factors Associated With Colonic Spirochete (Brachyspira pilosicoli and Brachyspira aalborgi) Infection: A Comprehensive Systematic Review and Pooled Analysis

OBJECTIVES

This study aims to determine what pathologic and clinical factors differentiate Brachyspira species that may be useful to clinicians and pathologists.

METHODS

We identified 21 studies of Brachyspira infection with individual patient information (n = 113) and conducted a pooled analysis comparing each species.

RESULTS

There were differences in the pathologic and clinical profiles of each Brachyspira species. Patients infected with Brachyspira pilosicoli infection were more likely to have diarrhea, fever, HIV, and immunocompromised conditions. Those patients infected with Brachyspira aalborgi were more likely to have lamina propria inflammation.

CONCLUSIONS

Our novel data provide potential insights into the pathogenic mechanism(s) and the specific risk factor profile of Brachyspira species. This may be clinically useful when assessing and managing patients.

Increased Prevalence of Symptomatic Human Intestinal Spirochetosis in MSM with High-Risk Sexual Behavior in a Cohort of 165 Individuals

Human intestinal spirochetosis (HIS) can cause gastrointestinal symptoms, although asymptomatic infections have been described. Individuals from low-income countries, people living with HIV, and men who have sex with men (MSM) show increased risk. A retrospective review of all patients diagnosed with HIS (n = 165) between January 2013 and October 2020 at a tertiary hospital in Madrid, Spain, was performed to assess risk factors for symptomatic HIS, symptoms, and response to treatment. Most patients were male (n = 156; 94.5%), 86.7% were MSM, and 23.5% practiced chemsex, of whom most were symptomatic (p = 0.039). Most patients (78.4%) reported unprotected oral-anal intercourse. A total of 124 (81.1%) were symptomatic; diarrhea was the most common complaint (68.3%). Multivariable regression showed increased odds of symptoms associated with age under 41 (odds ratio 5.44, 95% CI 1.87-15.88; p = 0.002). Colonoscopy was normal in 153 (92.7%). Furthermore, 66.7% presented previous or concomitant sexually transmitted diseases (STDs). Among the patients, 102 underwent testing for other gastrointestinal pathogens, with positive results in 20 (19.6%). All symptomatic patients without concomitant gastrointestinal infection presenting improvement on follow-up (42 of 53) had received either metronidazole or doxycycline (p = 0.049). HIS should be considered as a cause of chronic diarrhea in MSM with high-risk sexual behavior after other causes have been ruled out; treatment with metronidazole is recommended. Coinfection with other STDs is common.

Human intestinal spirochetosis, irritable bowel syndrome, and colonic polyps: A systematic review and meta-analysis

Human colonic spirochetosis (CS) is usually due toBrachyspira pilosicolior Brachyspira aalborgiinfection. While traditionally considered to be commensal bacteria, there are scattered case reports and case series of gastrointestinal (GI) symptoms in CS and reports of colonic polyps with adherent spirochetes. We performed a systematic review and meta-analysis investigating the association between CS and GI symptoms and conditions including the irritable bowel syndrome (IBS) and colonic polyps. Following PRISMA 2020 guidelines, a systematic search of Medline, CINAHL, EMBASE, and Web of Science was performed using specific keywords for CS and GI disease. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Of 75 studies identified in the search, 8 case-control studies met the inclusion criteria for meta-analysis and 67 case series studies met the inclusion criteria for pooled prevalence analysis. CS was significantly associated with diarrhea (n = 141/127, cases/controls, OR: 4.19, 95% CI: 1.72-10.21, P = 0.002) and abdominal pain (n = 64/65, OR: 3.66, 95% CI: 1.43-9.35, P = 0.007). CS cases were significantly more likely to have Rome III-diagnosed IBS (n = 79/48, OR: 3.84, 95% CI: 1.44-10.20, P = 0.007), but not colonic polyps (n = 127/843, OR: 8.78, 95% CI: 0.75-103.36, P = 0.084). In conclusion, we found evidence of associations between CS and both diarrhea and IBS, but not colonic polyps. CS is likely underestimated due to suboptimal diagnostic methods and may be an overlooked risk factor for a subset of IBS patients with diarrhea.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): antimicrobial-resistant Brachyspira hyodysenteriae in swine

Brachyspira hyodysenteriae (B. hyodysenteriae) was identified among the most relevant antimicrobial-resistant (AMR) bacteria in the EU for swine in a previous scientific opinion. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9, and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with uncertain outcome. According to the assessment here performed, it is uncertain whether AMR B. hyodysenteriae can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (33-66% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that the bacterium does not meet the criteria in Sections 1, 2 and 3 (Categories A, B and C; 1-10%, 10-33% and 10-33% probability of meeting the criteria, respectively) and the AHAW Panel was uncertain whether it meets the criteria in Sections 4 and 5 (Categories D and E, 50-90% and 33-66% probability of meeting the criteria, respectively). The main animal species to be listed for AMR B. hyodysenteriae according to Article 8 criteria are pigs and some species of birds, such as chickens and ducks.

2021 European Guideline on the management of proctitis, proctocolitis and enteritis caused by sexually transmissible pathogens

This guideline intents to offer guidance on the diagnosis and management of patients with gastrointestinal symptoms and a suspected sexually transmitted cause. Proctitis is defined as an inflammatory syndrome of the anal canal and/or the rectum. Infectious proctitis can be sexually transmitted via genital-anal mucosal contact, but some also via digital contact and toys. Neisseria gonorrhoeae, Chlamydia trachomatis (including lymphogranuloma venereum), Treponema pallidum and herpes simplex virus are the most common sexually transmitted anorectal pathogens. Shigellosis can be transferred via oral-anal contact and may lead to proctocolitis or enteritis. Although most studies on these infections have concentrated on men who have sex with men (MSM), women having anal intercourse may also be at risk. A presumptive clinical diagnosis of proctitis can be made when there are symptoms and signs, and a definitive diagnosis when the results of laboratory tests are available. The symptoms of proctitis include anorectal itching, pain, tenesmus, bleeding, constipation and discharge in and around the anal canal. The majority of rectal chlamydia and gonococcal infections are asymptomatic and can only be detected by laboratory tests. Therefore, especially when there is a history of receptive anal contact, exclusion of anorectal infections is generally indicated as part of standard screening for sexually transmitted infections (STIs). Condom use does not guarantee protection from STIs, which are often spread without penile penetration. New in this updated guideline is: (i) lymphogranuloma venereum proctitis is increasingly found in HIV-negative MSM, (ii) anorectal Mycoplasma genitalium infection should be considered in patients with symptomatic proctitis after exclusion of other common causations such N. gonorrhoeae, C. trachomatis, syphilis and herpes, (iii) intestinal spirochetosis incidentally found in colonic biopsies should not be confused with syphilis, and (iv) traumatic causes of proctitis should be considered in sexually active patients.

Human intestinal spirochetosis, a sexually transmissible infection? Review of six cases from two sexually transmitted infection centres in Barcelona

Human intestinal spirochetosis (HIS) is a possible cause of chronic diarrhoea and affects mainly men who have sex with men (MSM) and people living with HIV. Diagnosis is based on colon biopsy, where spirochetes can be observed on the luminal surface, especially with the Warthin-Starry stain or similar silver stains. We conducted a retrospective descriptive study of all HIS cases diagnosed in two sexually transmitted infections (STI) centres in Barcelona from 2009 until 2018. The medical histories were reviewed to gather epidemiological, clinical, and diagnostic variables. Six patients were diagnosed with HIS. All the individuals were MSM, with a median age of 31.5 years (interquartile range [IQR] 29.5;49.25) and half of them were living with HIV. Five patients reported condomless anal intercourse and 4 patients had practised oro-anal sex previously. Concomitantly, two of them had rectal gonorrhoea, one had rectal Chlamydia trachomatis and none of them had syphilis. The predominant clinical symptom was diarrhoea (5 patients). All cases were diagnosed by a Warthin-Starry stain on a colon biopsy specimen, and mild inflammatory changes were found in 5 cases. Five patients were treated with metronidazole and one with benzathine penicillin G. Treatment was successful in all the patients. HIS should be considered in patients with chronic diarrhoea who report risky sexual practices and/or concomitant STI. HIS may also be sexually transmitted according to the context.

Hypothesis: nucleoid-associated proteins segregate with a parental DNA strand to generate coherent phenotypic diversity

The generation of a phenotypic diversity that is coherent across a bacterial population is a fundamental problem. We propose here that the DNA strand-specific segregation of certain nucleoid-associated proteins or NAPs results in these proteins being asymmetrically distributed to the daughter cells. We invoke a variety of mechanisms as responsible for this asymmetrical segregation including those based on differences between the leading and lagging strands, post-translational modifications, oligomerisation and association with membrane domains.