Cat-scratch disease: a rare cause of osteomyelitis.

Cat-scratch disease is a zoonosis caused by Bartonella henselae, characterised by regional lymphadenopathy. Rarer presentations, such as osteomyelitis, can occur.We present an adolescent girl with severe right lumbar pain and fever, without animal contacts or recent travels. On examination, pain on flexion of torso, movement limitation and marked lordosis were noted, but there were no inflammatory signs, palpable masses or lymph nodes. Serological investigations revealed elevated inflammatory markers. Imaging revealed a paravertebral abscess with bone erosion. Several microbiological agents were ruled out. After a second CT-guided biopsy, PCR for Bartonella spp was positive. At this point, the family recalled having a young cat some time before. Cat-scratch disease was diagnosed, and complete recovery achieved after treatment with doxycycline and rifampicin.Cat-scratch disease is a challenging diagnosis in the absence of typical features. However, B. henselae must be investigated if common pathogens are ruled out and response to therapy is poor.

Post-COVID reactivation of latent Bartonella henselae infection: a case report and literature review.

Cat scratch disease (CSD) is caused by Bartonella henselae (B. henselae) and presents as lymphadenopathy following close contact with cats. However, in context of the global COVID-19 pandemic, clinical manifestations of CSD may vary, posing new challenges for healthcare professionals. Here we describe a case of a 54-year-old male with painful left upper arm mass, which gradually resolved until he was infected with COVID-19. The mass then rapidly progressed before admission. Meanwhile, pulmonary symptoms including pleural effusion emerged simultaneously. The cause was undetermined with routine blood culture and pathological test until the next generation sequencing (NGS) confirmed the presence of B. henselae. We believe this case is the first to report localized aggravation of CSD after COVID-19 infection and hopefully, offers treatment experience for clinicians worldwide.

Unmasking Bartonella henselae infection in the shadows of long COVID thanks to clinical metagenomics.

The diagnosis of long COVID often relies on symptoms post-COVID-19, occasionally lacking biological evidence. This case study illustrates how investigating long COVID uncovered an underlying bartonellosis through clinical metagenomics. Following mild COVID-19, a 26-year-old woman experienced persistent symptoms during 5 months, including axillary adenopathy. Pathological examination, 16 S rRNA PCR, and clinical metagenomic analysis were done on an adenopathy biopsy. The latter revealed Bartonella henselae DNA and RNA. Treatment with clarithromycin improved symptoms. This case underscores the relevance of clinical metagenomics in diagnosing hidden infections. Post-COVID symptoms warrant thorough investigation, and bartonellosis should be considered in polyadenopathy cases, regardless of a recent history of cat or flea exposures.

Bartonella henselae Infection and Lymphadenopathy in a Patient With T Cell Acute Lymphoblastic Leukemia.

Patients undergoing therapy for T cell acute lymphoblastic leukemia are at risk of infections during their treatment course. Cat scratch disease caused by Bartonella hensalae can masquerade as leukemic relapse and cause systemic infection. Obtaining a thorough exposure history may aid clinicians in making the diagnosis.

A comparison of Bartonella henselae infection in immunocompetent and immunocompromised mice.

Bartonellosis refers to disease caused by the Bartonella genus of bacteria. The breadth of disease manifestations associated with Bartonella is currently expanding and includes regional lymphadenopathy, rheumatic, ocular, and neurological disorders. The dearth of knowledge regarding diagnosis, treatment and pathogenesis of this disease can be partially attributed to the lack of a reliable small animal model for the disease. For this study, Bartonella henselae, the most common species associated with human disease, was injected into Swiss Webster (SW) mice. When the outcome indicated that productive infection did not occur, SCID/Beige (immune compromised) mice were inoculated. While SW mice may potentially harbor an acute infection, less than 10 days in length, the SCID/Beige model provided a sustained infection lasting up to 30-days. These data indicate that SCID/Beige mice can provide a model to study Bartonella infection, therapeutics, and vector dynamics in the future.

The influence of growth time on the identification of Bartonella henselae strains by MALDI-TOF mass spectrometry.

Bartonella spp. are bacteria responsible for neglected diseases worldwide. Bartonella henselae is the species most associated with human infections. It is associated with a large spectrum of clinical manifestations and is potentially fatal. The identification of Bartonella spp. is considered a challenge in clinical routine. These bacteria are fastidious, and the time required to isolate them varies from one to six weeks. MALDI-TOF mass spectrometry has emerged as an application for research on Bartonella spp. , and has still been little explored. We investigated whether three different B. henselae strains with different growth times-14 and 28 days-could be correctly identified by MALDI-TOF mass spectra fingerprint comparison and matching. We found that the spectra from strains with different growth times do not match each other, leading to misidentification. We suggest creating database entries with multiple spectra from strains with different growth times to increase the chances of accurate identification of Bartonella spp. by MALD-TOF MS.

Genetic diversity of Bartonella rpoB haplotypes in domestic cats from Chile.

The study aimed to determine the inter and intra-host Bartonella spp. genetic diversity in cats from Chile. 'Seventy-nine cats' blood DNA samples qPCR Bartonella spp. positive were subjected to T-A cloning of Bartonella spp. rpoB partial gene (825 bp), and sequencing by Sanger method. The sequences were submitted to phylogenetic and polymorphism analysis. Thirty-six (45.6%) samples were successfully cloned, generating 118 clones of which 109 showed 99.6%-100% identity with Bartonella henselae whereas 9 showed 99.8-100% identity with Bartonella koehlerae. Haplotype analysis yielded 29 different rpoB-B. henselae haplotypes, one (hap#2) overrepresented in 31 out of 33 cats, and 4 rpoB-B. koehlerae haplotypes, with hap#2 represented in all 3 B. koehlerae infected cats. More than one rpoB -B. henselae and B. koehlerae haplotypes were identified in individual cats, reporting by first time coinfection by different B. henselae/B. koehlerae rpoB variants in cats from Chile.

Epidemiology of Bartonella henselae infection in pet and stray cats in Croatia with risk factors analysis.

BACKGROUND: Cats are the primary reservoirs of the bacterium Bartonella henselae, the main cause of cat-scratch disease in humans. The main vector of the bacterium is the cat flea, Ctenocephalides felis. In southeastern Europe, data are lacking on the prevalence of B. henselae infection in cats, the strains of B. henselae involved and the risk factors associated with the infection. METHODS: Blood samples collected in ethylenediaminetetraacetic acid-containing tubes from 189 domestic cats (156 pet cats and 33 stray cats) from Zagreb, the capital city of Croatia, and 10 counties throughout Croatia were cultured for Bartonella spp. Following culture, bacterial isolates were genotyped at eight loci after using PCR to amplify 16S ribosomal RNA (rRNA) and the internal transcribed spacer region between the 16S and 23S rRNA sequences. Univariate and multivariate logistic regression were used to identify risk factors for B. henselae infection in cats. RESULTS: Bartonella spp. was detected in 31 cats (16.4%), and subsequent genotyping at the eight loci revealed B. henselae in all cases. Thirty complete multilocus sequence typing profiles were obtained, and the strains were identified as four sequence types that had been previously reported, namely ST5 (56.7%), ST6 (23.3%), ST1 (13.3%) and ST24 (3.3%), as well as a novel sequence type, ST33 (3.3%). The univariate analysis revealed a significantly higher risk of B. henselae infection in cats residing in coastal areas of Croatia (odds ratio [OR] 2.592, 95% confidence interval [CI] 1.150-5.838; P = 0.0191) and in cats with intestinal parasites (OR 3.207, 95% CI 1.088-9.457; P = 0.0279); a significantly lower risk was identified in cats aged > 1 year (OR 0.356, 95% CI 0.161-0.787; P = 0.0247) and in cats sampled between April and September (OR 0.325, 95% CI 0.147-0.715; P = 0.005). The multivariate analysis that controlled for age showed a positive association with the presence of intestinal parasites (OR 4.241, 95% CI 1.243-14.470; P = 0.0119) and coastal residence (OR 2.567, 95% CI 1.114-5.915; P = 0.0216) implying increased risk of infection, and a negative association with sampling between April and September (OR 0.379, 95% CI 0.169-0.848; P = 0.018) implying a decreased risk of infection. After controlling for the season, an increased risk of infection remained for the coastal region (OR 2.725, 95% CI 1.200-6.186; P = 0.012). CONCLUSIONS: Bartonella henselae is prevalent throughout Croatia and is a public health threat. Environmental and host factors can significantly affect the risk of infection, and these should be explored in more detail. The presence of intestinal parasites highlights the need to eliminate the flea vector, Ctenocephalides felis, as the most effective approach to control infections in cats and humans.

Genomic detection and phylogenetic analysis of Bartonella quintana in pet cats from Urmia City, Northwest Iran.

The aim of this study was to investigate the presence and genetic characteristics of Bartonella quintana in pet cats from Urmia City, located in the northwest of Iran. Blood samples were collected from 200 cats, and their age, gender, and breed were noted. Nested-PCR and sequencing were used to identify B. quintana in positive samples, and the ftsZ gene sequences were analyzed using BioEdit software. The gene sequence obtained in this study exhibited 100.00 % similarity to reference sequences in the GenBank® database, and a phylogenetic tree was constructed using MEGA11. The results revealed that 15 % of the cats (30 out of 200 blood samples) tested positive for the B. quintana gene, with a 95 % confidence interval of 10.71 % to 20.61 %.

An autochthonous case of cutaneous bacillary angiomatosis not related to major immunosuppression: An emerging or overlooked disease?

Cutaneous bacillary angiomatosis (cBA) is a vascular proliferative disorder due to Bartonella henselae or Bartonella quintana that has been mostly described in people living with HIV. Since cBA is considered to be rare in hosts not affected by major immunosuppression, it could be underdiagnosed in this population. Moreover, antimicrobial treatment of cBA has been poorly validated, thus reporting experiences on this clinical entity is important. We reported a challenging and well-characterized case of an Italian 67-year-old gentleman without a history of major immunocompromizing conditions, although he was affected by conditions that can be associated with impaired immune function. The patient reported herein was diagnosed after a long time since the initiation of symptoms and was successfully treated with combined antibiotic therapy including macrolides and quinolones under the guidance of molecular test results. Physicians should consider cBA as a possible manifestation of Bartonella spp. Infection in patients not suffering from major immunocompromizing conditions. Until evidence-based guidelines are available, molecular tests together with severity and extension of the disease can be useful to personalize the type of treatment and its duration.

Variantes en la presentación clínica de la enfermedad por arañazo de gato en niños del hospital Garrahan / Variants in the clinical presentation of cat scratch disease in children at Garrahan Hospital

La infección por Bartonella henselae (BH) adopta diversas formas de presentación clínica en pediatría. Según la bibliografía la forma de presentación más frecuente en pacientes inmunocompetentes es la linfadenopatía única asociada a fiebre. En el 85 % de los casos se compromete un solo ganglio siendo los axilares y los epitrocleares los más frecuentemente involucrados. Existen otras formas de presentación menos frecuentes que debemos tener en consideración, para poder realizar un diagnóstico precoz e indicar un tratamiento adecuado si así lo requiere. El diagnóstico requiere de la sospecha clínica del equipo de salud tratante, junto al antecedente epidemiológico, los hallazgos clínicos del examen físico y la realización de serologías que incluyan el dosaje de inmunoglobulina M y G. Los objetivos del presente trabajo fueron reconocer las manifestaciones clínicas típicas y atípicas de la EAG por Bartonella henselae, describir la epidemiología, características clínicas y evolución de esta enfermedad que se presentaron en nuestro hospital. Se estudiaron un total de 187 pacientes. La media de edad fue de 7.6 años (rango 1-14); siendo 53.5% de género masculino. Las formas de presentación más frecuentes en nuestro trabajo fueron la adenitis y la fiebre. La mayoría recibió diversos esquemas de tratamiento antibiótico, secundario al retraso en el diagnóstico. La tasa de hospitalización fue muy baja, remitió con tratamiento ambulatorio con antibióticos o sin ellos (AU)

Bartonella henselae infection has different clinical presentations in pediatrics. According to the literature, the most common form of presentation in immunocompetent patients is single lymphadenopathy associated with fever. In 85 % of the cases a single lymph node is involved, with the axillary and epitrochlear nodes being the most commonly involved. There are other, less frequent, forms of presentation that should be taken into consideration in order to make an early diagnosis and indicate appropriate treatment if required. Diagnosis relies on clinical suspicion by the treating healthcare team, together with the epidemiological history, clinical findings on physical examination, and serology including immunoglobulin M and G dosage. The objectives of this study were to identify both the typical and atypical clinical manifestations of Bartonella henselae cat scratch disease, to describe the epidemiology, clinical characteristics, and outcomes of cases presenting at our hospital. A total of 187 patients were studied. The mean age was 7.6 years (range 1-14); 53.5% were male. The most frequent forms of presentation in our study were adenitis and fever. Most of them received different antibiotic treatment regimens due to delayed diagnosis. The hospitalization rate was very low and the disease typically resolved with outpatient treatment, with or without antibiotics (AU)

Bartonella henselae as a putative trigger for chronic type 2 leprosy reactions.

Leprosy reactions are an acute inflammatory phenomenon that can arise before diagnosis, during treatment, or after cure of leprosy. These reactions are considered one of the main diseases that cause physical disabilities. Immunosuppressive treatment for these immune responses makes these patients susceptible to coinfections, which can trigger new leprosy reactions. The main objective of this study was to evaluate the occurrence of infection by Bartonella sp. in blood samples from 47 patients who had untreatable episodes of type 2 leprosy reactions for more than six months, comparing them with a control group. Cultures and molecular methods (PCR) were used. Amplicons from species-specific reactions and sequencing showed a higher prevalence of Bartonella henselae infection in patients, 19/47 (40.4 %), compared to control, 9/50 (18.0 %), p = 0.0149. Five patients accepted treatment for coinfection, and all showed improvement in leprosy reactions with treatment for B. henselae infection. We conclude that these bacteria can trigger chronic reactions of type 2 leprosy and should be investigated in these patients. SUMMARY LINE: Patients who have chronic type 2 leprosy reactions are more susceptible to Bartonella henselae infection than controls: 19/47 (40.4 %) compared 9/50 (18.0 %), p = 0.0149.

Acute perimyocarditis associated with Bartonella henselae infection.

Perimyocarditis involves inflammation of the heart muscle and surrounding tissue, causing reduced left ventricular ejection fraction. Typically viral, but occasionally bacterial, this condition can arise from Bartonella henselae, a rare yet potentially serious pathogen that can lead to cardiac inflammation and subsequent heart failure. Since this bacterium is mainly associated with cat scratch disease-which is self-limiting and has a mild disease course-B. henselae's potential role in cardiac disease is underestimated. We present a mid-30s man, immunocompetent, who presented to the emergency department with acute heart failure due to B. henselae-associated perimyocarditis. Despite not recalling any scratches or bites from cats, the patient had been living with cats, which likely exposed him. This case highlights the varied clinical presentations of B. henselae-associated heart disease and underscores the importance of considering this pathogen as a potential cause of perimyocarditis, particularly in individuals with exposure to cats.

Genetic characterization of Bartonella henselae samples isolated from stray cats by multi-locus sequence typing.

BACKGROUND: Bartonella henselae is one of the most commonly identified Bartonella species associated with several human diseases. Although B. henselae was detected in humans and cats in Turkey, they have not been genotyped previously. Therefore, this study aimed to genotype B. henselae samples (n = 44) isolated from stray cats using the multi-locus sequence typing (MLST) method. For this aim, eight different housekeeping markers were amplified by nested PCR and then sequenced to reveal sequence types (STs) of B. henselae samples. RESULTS: Allelic profiles obtained from 40 B. henselae isolates (90.9%) were compatible with available allelic profiles in the MLST online database. However, allelic profiles obtained from the remaining 4 B. henselae isolates (9.1%) were incompatible with the database. Among B. henselae isolates with compatible allelic profiles, 5 different STs including ST1, ST5, ST9, ST35 and ST36 were identified according to the B. henselae MLST online database. ST35 was the most prevalent ST with a prevalence rate of 29.5% (13/44), followed by ST36 with a prevalence rate of 22.7% (10/44). In addition, ST5 (16%, 7/44) and ST9 (18.2%, 8/44) were also among the prevalent STs. The prevalence of ST1 was 4.5% (2/44). For B. henselae isolates with incompatible allelic profiles, we recommended a new ST called ST38. CONCLUSION: The present study genotyped B. henselae samples isolated from stray cats in Turkey for the first time and ST1, ST5, ST9, ST35, and ST36 as well as a new sequence type named ST38 were identified among these B. henselae isolates.

CENTRAL RETINAL ARTERY OCCLUSION AS PRESENTATION OF BARTONELLA ENDOCARDITIS.

BACKGROUND/PURPOSE: To describe a rare ocular presentation of a systemic illness and the important lifesaving diagnosis made by a complete eye examination. METHODS: The patient was evaluated with a comprehensive ophthalmic examination and followed closely in the outpatient setting with optical coherence tomography, fluorescein angiography, and color fundus photos. RESULTS: A 66-year-old man presented with acute vision loss of the left eye. A complete eye examination revealed that he had a central retinal artery occlusion. Systemic workup revealed that he had a mitral valve vegetation and blood cultures grew Bartonella henselae. His kidney biopsy showed membranoproliferative glomerulonephritis, which is often seen with septic emboli. Furthermore, the patient lacked any ocular inflammatory signs. This constellation of findings was diagnostic for a thromboembolic etiology causing his central retinal artery occlusion. At follow-up, the optical coherence tomography demonstrated inner retinal hyperreflectivity and the fluorescein angiogram showed segmented flow and no neovascularization. On follow-up, the patient had a stable examination with light perception vision and completed antibiotic therapy for bartonella endocarditis. CONCLUSION: The detection of a fatal systemic illness was made promptly with a thorough ocular examination. We highlight the importance of a multidisciplinary approach in making a lifesaving diagnosis.