Clinical and pathological features of bacillary peliosis hepatis in association with human immunodeficiency virus infection

Molecular survey and genetic diversity of Bartonella spp. in domestic cats from Paraguay

Although Bartonella spp. is described in cats worldwide, little is known about the occurrence and genetic diversity of Bartonella spp. in cats from South America. To date, it has only been detected in cats from Brazil, Chile and Argentina. This study aimed to undertake a molecular survey and explore the genetic diversity of Bartonella spp. in domestic cats from Paraguay. A TaqMan real-time quantitative PCR (qPCR) targeting the nuoG gene (83 bp) for Bartonella spp. was used to screen 125 blood samples from cats in Asuncion, Paraguay. nuoG qPCR-positive samples were further submitted to conventional PCR assays based on the ITS (453- 717 bp), gltA (767 bp), ftsZ (515 bp), rpoB (333 bp), ribC (585-588 bp), and pap-31 (564 bp) loci. Positive samples were sequenced for species identification, phylogenetic, and haplotype analyses. Bartonella D.N.A. was present in 20.8% (26/125) cat blood samples, with low levels of Bartonella nuoG D.N.A. cPCR products targeting gltA, ftsZ, ITS, and rpoB loci from sixteen cats were successfully sequenced. However, all nouG qPCR-positive samples were negative for the ribC and pap-31 genes. Bartonella henselae [62.5% (10/16)] and Bartonella clarridgeiae [37.5% (6/16)] were identified among the sequenced samples. Upon phylogenetic analysis, B. henselae and B. clarridgeiae from Paraguay clustered with sequences detected in domestic and wild cats, dogs, and cat fleas worldwide. Two to four haplotypes of B. henselae and B. clarridgeiae in cats from Paraguay were observed, with some being exclusive and others shared with worldwide distributed haplotypes. Here, we report B. henselae and B. clarridgeiae for the first time in cats from Paraguay. Its circulation in cats suggests the need to consider Bartonellae when testing clinical samples from suspected infectious diseases in humans from Paraguay.

Peliosis Hepatis with Chylous Ascites in a Dog

A 6-year-old spayed female Toy Poodle dog was referred to the Hokkaido University Veterinary Teaching Hospital for abdominal distension. Abdominocentesis yielded ascitic fluid that had a mildly increased total protein concentration and a 2.7-fold higher triglyceride concentration than plasma, and was interpreted as chylous ascites. The patient had an enlarged liver, which contained multiple, small, nodular masses and cyst-like structures. Microscopically, these lesions were multifocal dilated spaces containing lymphocytes, endothelial cells, fibrin and islands of hepatocytes. Increased α-smooth muscle actin-positive cells were observed in hepatic sinusoids. Based on these findings, we diagnosed peliosis hepatis with chylous ascites, which is likely to have been due to lymphangiectasia and disrupted hepatic sinusoids. Neither Bartonella spp DNA nor mutations in ACVRL1 and MTM1 genes were detected, although there was a 47-fold increase in hepatic ACVRL1 expression compared with age-matched control liver. To the authors' knowledge, this is the first report of chylous ascites resulting from peliosis hepatis in any species.

Hepatic lesions in captive owl monkeys (Aotus infulatus) with ultrasonographic "starry sky" liver

BACKGROUND

The "starry sky" (SK) liver is ultrasonographic pattern characterized by multiple hyperechogenic foci in hepatic parenchyma. The study aimed to characterize the microscopic hepatic lesions in captive owl monkeys with SK liver.

METHODS

Thirty-seven clinically healthy owl monkeys had their liver scanned and 18 of them had liver biopsy. Animals with SK and peliosis hepatis (PH) were subjected to immunohistochemical and molecular screening for Bartonella spp.

RESULTS

SK liver occurred in 59.4% (22/37) of the owl monkeys. Biopsied animals showed steatosis, hydropic degeneration, hemosiderosis, PH, and multifocal granulomatous hepatitis. Two monkeys had SK, granulomatous hepatitis, and PH which were negative for Bartonella spp.

CONCLUSIONS

PH and granulomatous hepatitis associated with hepatocellular degenerative lesions may present as hyperechoic nodular liver lesions consisted of SK liver; therefore, concomitant occurrence of two lesions or more contributed to the hepatic SK pattern among owl monkeys and such cases might be clinically monitored.

Bartonellosis in transplant recipients: A retrospective single center experience

BACKGROUND

Bartonellosis is a rare but challenging condition to diagnose with a spectrum of clinical presentations in the immunocompromised host.

AIM

To further characterize the presentation of Bartonella henselae (B. henselae) infections in solid organ and hematopoietic stem cell transplant recipients.

METHODS

We conducted a single-center retrospective study of all B. henselae testing for 5012 transplant recipients receiving care at a single institution between 2011 and 2018.

RESULTS

We identified 38 patients who underwent testing for B. henselae, and three of 38 were found to have bartonellosis. Two of the patients were renal transplant recipients who presented with visceral bartonellosis and symptoms concerning for post-transplant lymphoproliferative disorder. One autologous stem cell transplant recipient presented with cat scratch disease. We detail the clinical courses of these three cases and review the literature concerning the clinical presentations, differential diagnosis, and limitations of diagnostic tests for B. henselae infections in transplant recipients.

CONCLUSION

Although the incidence of B. henselae infection in transplant recipients is unknown, it merits inclusion in the differential diagnosis for fever of unknown origin in this population.

Cat Scratch Disease and Bartonellaceae: The Known, the Unknown and the Curious

Since the early 1900s, Bartonella species were known only to cause human disease resulting from very restricted geographic (bartonellosis) or environmental influences ("trench fever"). In the 1990s, and in parallel, cat scratch disease and bacillary angiomatosis were definitively linked to Bartonella species. Subsequently, widespread use of modern diagnostic methods revealed the broad ecologic niche of this organism and greatly expanded our knowledge of the epidemiology and clinical presentations associated with this genus. A large number of reservoirs and vectors involved with Bartonella propagation and transmission to humans have been identified; cats and various arthropods remain the most well-studied to date. Though not completely understood, it appears that specific immune-modulated interactions between the infecting species and host-related factors play a major role in the observed breadth of human clinical syndromes associated with Bartonellae, the large differences in immunopathologic features of tissue samples among different syndromes and potentially the varied responses to antimicrobial therapy. Further, the clinical management for cat scratch disease in particular is quite variable among clinicians, reflecting a poor evidence base. No preventive measures have been developed beyond suggestions to avoid at-risk behavior with known vectors.

What Is in a Cat Scratch? Growth of Bartonella henselae in a Biofilm

Bartonella henselae (B. henselae) is a gram-negative bacterium that causes cat scratch disease, bacteremia, and endocarditis, as well as other clinical presentations. B. henselae has been shown to form a biofilm in vitro that likely plays a role in the establishment and persistence of the bacterium in the host. Biofilms are also known to form in the cat flea vector; hence, the ability of this bacterium to form a biofilm has broad biological significance. The release of B. henselae from a biofilm niche appears to be important in disease persistence and relapse in the vertebrate host but also in transmission by the cat flea vector. It has been shown that the BadA adhesin of B. henselae is critical for adherence and biofilm formation. Thus, the upregulation of badA is important in initiating biofilm formation, and down-regulation is important in the release of the bacterium from the biofilm. We summarize the current knowledge of biofilm formation in Bartonella species and the role of BadA in biofilm formation. We discuss the evidence that defines possible mechanisms for the regulation of the genes required for biofilm formation. We further describe the regulation of those genes in the conditions that mimic both the arthropod vector and the mammalian host for B. henselae. The treatment for persistent B. henselae infection remains a challenge; hence, a better understanding of the mechanisms by which this bacterium persists in its host is critical to inform future efforts to develop drugs to treat such infections.

[Liver sinusoids: pathology of endothelial findings]

This review covers a spectrum of pathologic changes and diseases involving hepatic sinusoids. In the majority of patients, clinical findings are rather uncharacteristic such as hepatomegaly, portal hypertension, or lingering liver failure of unknown origin. In contrast to more common hepatic disorders, characteristic clinical, serological, immunoserological, and radiographical findings are lacking. In these cases, biopsy findings may be crucial to guide treatment decisions. This review covers a variety of hepatic disorders that practicing pathologists may encounter in their clinical routine.

Molecular prevalence of Bartonella, Babesia, and hemotropic Mycoplasma species in dogs with hemangiosarcoma from across the United States

Hemangiosarcoma (HSA), a locally invasive and highly metastatic endothelial cell neoplasm, accounts for two-thirds of all cardiac and splenic neoplasms in dogs. Bartonella spp. infection has been reported in association with neoplastic and non-neoplastic vasoproliferative lesions in animals and humans. The objective of this study was to determine the prevalence of Bartonella spp. in conjunction with two other hemotropic pathogens, Babesia spp. and hemotropic Mycoplasma spp., in tissues and blood samples from 110 dogs with histopathologically diagnosed HSA from throughout the United States. This was a retrospective, observational study using clinical specimens from 110 dogs with HSA banked by the biospecimen repository of the Canine Comparative Oncology and Genomics Consortium. Samples provided for this study from each dog included: fresh frozen HSA tumor tissue (available from n = 100 of the 110 dogs), fresh frozen non-tumor tissue (n = 104), and whole blood and serum samples (n = 108 and 107 respectively). Blood and tissues were tested by qPCR for Bartonella, hemotropic Mycoplasma, and Babesia spp. DNA; serum was tested for Bartonella spp. antibodies. Bartonella spp. DNA was amplified and sequenced from 73% of dogs with HSA (80/110). In contrast, hemotropic Mycoplasma spp. DNA was amplified from a significantly smaller proportion (5%, p<0.0001) and Babesia spp. DNA was not amplified from any dog. Of the 100 HSA tumor samples submitted, 34% were Bartonella PCR positive (32% of splenic tumors, 57% of cardiac tumors, and 17% of other tumor locations). Of 104 non-tumor tissues, 63% were Bartonella PCR positive (56% of spleen samples, 93% of cardiac samples, and 63% of skin/subcutaneous samples). Of dogs with Bartonella positive HSA tumor, 76% were also positive in non-tumor tissue. Bartonella spp. DNA was not PCR amplified from whole blood. This study documented a high prevalence of Bartonella spp. DNA in dogs with HSA from geographically diverse regions of the United States. While 73% of all tissue samples from these dogs were PCR positive for Bartonella DNA, none of the blood samples were, indicating that whole blood samples do not reflect tissue presence of this pathogen. Future studies are needed to further investigate the role of Bartonella spp. in the development of HSA.

Bleeding Liver Masses: Imaging Features With Pathologic Correlation and Impact on Management

OBJECTIVE. The purposes of this article are to discuss a variety of liver masses that can present with hemorrhage, including their characteristic imaging features, and to propose a diagnostic approach. CONCLUSION. A broad spectrum of pathologic conditions can present as spontaneous hemorrhage within or surrounding the liver and may present acutely or as a chronic or incidental finding. Imaging characteristics and clinical history can often narrow the differential diagnosis and guide management.

The trimeric autotransporter adhesin BadA is required for in vitro biofilm formation by Bartonella henselae

Bartonella henselae (Bh) is a Gram-negative rod transmitted to humans by a scratch from the common house cat. Infection of humans with Bh can result in a range of clinical diseases including lymphadenopathy observed in cat-scratch disease and more serious disease from persistent bacteremia. It is a common cause of blood-culture negative endocarditis as the bacterium is capable of growing as aggregates, and forming biofilms on infected native and prosthetic heart valves. The aggregative growth requires a trimeric autotransporter adhesin (TAA) called Bartonella adhesin A (BadA). TAAs are found in all Bartonella species and many other Gram-negative bacteria. Using Bh Houston-1, Bh Houston-1 ∆badA and Bh Houston-1 ∆badA/pNS2PTrc badA (a partial complement of badA coding for a truncated protein of 741 amino acid residues), we analyze the role of BadA in adhesion and biofilm formation. We also investigate the role of environmental factors such as temperature on badA expression and biofilm formation. Real-time cell adhesion monitoring and electron microscopy show that Bh Houston-1 adheres and forms biofilm more efficiently than the Bh Houston-1 ∆badA. Deletion of the badA gene significantly decreases adhesion, the first step in biofilm formation in vitro, which is partially restored in Bh Houston-1 ∆badA/pNS2PTrc badA. The biofilm formed by Bh Houston-1 includes polysaccharides, proteins, and DNA components and is susceptible to enzymatic degradation of these components. Furthermore, both pH and temperature influence both badA expression and biofilm formation. We conclude that BadA is required for optimal adhesion, agglutination and biofilm formation.

Cat-Scratch Disease in an AIDS Patient Presenting with Generalized Lymphadenopathy: An Unusual Presentation with Delayed Diagnosis

Patient: Female, 44

Final Diagnosis: Cat-scratch disease

Symptoms: Lymfadenopathy

Medication: —

Clinical Procedure: Lymph node biopsy

Specialty: Infectious Diseases

Bartonella henselae infection presenting as cervical spine osteomyelitis: case report

Bartonella henselae is a gram-negative bacillus implicated in cat-scratch disease. Cat-scratch disease is usually self-limiting and results in local lymphadenopathy. In rare circumstances, patients may develop endocarditis, neuroretinitis, or osteomyelitis. Osteomyelitis of the cervical spine is exceedingly rare, especially in the pediatric population, and to date there have been only 4 previously reported cases of cervical spine osteomyelitis caused by B. henselae, all of which were treated surgically. In this article, the authors report the case of a 7-year-old boy who presented with neck swelling and was found to have a C2-4 paravertebral B. henselae abscess with osteomyelitis of C-3 and epidural extension. To the authors' knowledge, this represents the first case in the literature of a cervical spine B. henselae infection managed conservatively.

The contribution of culturomics to the repertoire of isolated human bacterial and archaeal species

After a decade of research and metagenomic analyses, our knowledge of the human microbiota appears to have reached a plateau despite promising results. In many studies, culture has proven to be essential in describing new prokaryotic species and filling metagenomic gaps. In 2015, only 2172 different prokaryotic species were reported to have been isolated at least once from the human body as pathogens or commensals. In this review, we update the previous repertoire by reporting the different species isolated from the human body to date, increasing it by 28% to reach a total of 2776 species associated with human beings. They have been classified into 11 different phyla, mostly the Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. Finally, culturomics contributed up to 66.2% towards updating this repertoire by reporting 400 species, of which 288 were novel. This demonstrates the need to continue the culturing work, which seems essential in order to decipher the hidden human microbial content.

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.

Primary Hepatic Neoplasms of Vascular Origin: Key Imaging Features and Differential Diagnoses With Radiology-Pathology Correlation

OBJECTIVE

This article describes, illustrates, and correlates imaging and pathologic features of primary vascular mesenchymal neoplasms of the liver, which arise from the vascular endothelium and perivascular epithelioid cells.

CONCLUSION

Familiarity with the spectrum of benign, malignant-potential and malignant vascular neoplasms, and nonneoplastic mimickers allows consideration in the differential diagnosis of enhancing hepatic masses. Understanding relevant pathologic features facilitates recognition of key imaging features, specifically dynamic contrast enhancement patterns on CT and MRI, which provide a useful classification system.

Sepsis and Challenging Infections in the Immunosuppressed Patient in the Intensive Care Unit

In 2017, most intensive care units (ICUs) worldwide are admitting a growing population of immunosuppressed patients. The most common causes of pre-ICU immunosuppression are solid organ transplantation, hematopoietic stem cell transplantation, and infection due to human immunodeficiency virus. In this article, the authors review the most frequent infections that cause critical care illness in each of these 3 immunosuppressed patient populations.

Molecular detection of Bartonella henselae in 11 Ixodes ricinus ticks extracted from a single cat

BACKGROUND

Bartonella henselae is a highly prevalent, vector-borne pathogen. Transmission to humans and animals by ticks is discussed controversially. Here, we present a case report, where eleven Ixodes ricinus ticks all harbouring B. henselae DNA were removed from one single cat.

RESULTS

The first feeding tick was tested positive for B. henselae DNA. The cat was also found to be seropositive for anti-B. henselae IgG antibodies (titer 1:640). Bartonella henselae was not cultivatable from cat blood. Ten more feeding ticks removed 7 months later contained also B. henselae DNA. Sequence analysis of the 16SrDNA and the 16S-23S internal transcribed spacer (ITS) region revealed 100% sequence homology between all ticks. Bartonella adhesin A (badA) and VirB/VirD4 type IV secretion system (virB) DNA were also detected in all ticks.

CONCLUSIONS

Our results indicate that cats may serve as a reservoir for adult ticks to acquire B. henselae. Whether this observation implies an increased threat for human and animal health needs to be resolved.

Resolution of spontaneous hemoabdomen secondary to peliosis hepatis following surgery and azithromycin treatment in a Bartonella species infected dog

OBJECTIVE

To describe a case of hemoperitonium in a dog with Bartonellosis and peliosis hepatis (PH) lesions that resolved following antimicrobial therapy.

CASE SUMMARY

A 3-year-11-month-old 22.5 kg female spayed mixed breed dog presented for progressive lethargy and vomiting. An abdominal ultrasonographic examination revealed moderate ascites, which when sampled was nonclotting hemorrhagic fluid. An exploratory laparotomy revealed a large volume of nonclotted blood in the dog's abdomen and blood-filled vesicular lesions dispersed diffusely along multiple lobes of the liver. Biopsies revealed lesions indicative of PH. Serology testing for Bartonella species was positive. Treatment with azithromycin resulted in Bartonella serology negative status and no further evidence of hemoperitonium at recheck examination 12 months after initial presentation.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first reported case of PH and hemoperitoneum in a Bartonella species serology positive dog wherein treatment with azithromycin resulted in serology negative status. There have been no subsequent episodes of hemoperitoneum in the 12 months since treatment.

The significance of nonobstructive sinusoidal dilatation of the liver: Impaired portal perfusion or inflammatory reaction syndrome

Sinusoidal dilatation found in the absence of an impaired sinusoidal blood outflow has been so far of unclear significance. Sinusoidal dilatation may actually be a nonspecific feature of impaired portal venous blood inflow, whatever the cause, or a feature of severe systemic inflammatory reaction syndrome, whatever the cause. Sinusoidal dilatation is mainly located in the centrilobular area even in the absence of an outflow block. A predominantly periportal location is specifically found in oral contraceptive users, associated with an inflammatory condition. There is strong evidence for the association of sinusoidal dilatation and oxaliplatin-based chemotherapy but not for estroprogestative steroids or thiopurine derivatives. Exposure to anabolic androgen steroids appears to cause sinusoidal changes different from a mere sinusoidal dilatation.

CONCLUSION

There is evidence of activation of the interleukin-6 and vascular endothelial growth factor pathways in sinusoidal dilatation, but the mechanisms linking the activation of these pathways with the microvascular changes must be identified.

Visceral cat scratch disease with endocarditis in an immunocompetent adult: a case report and review of the literature

Infective endocarditis and hepatosplenic abscesses are rare manifestations of cat scratch disease (CSD), especially among immunocompetent adults. An otherwise healthy woman who presented with fever and abdominal pain was diagnosed with multiple abscesses in the spleen and the liver, as well as a mitral valve vegetation. PCR on spleen tissue was positive for Bartonella henselae. Prolonged treatment with doxycycline and gentamicin led to complete recovery. Review of the literature revealed 18 cases of hepatosplenic CSD in immunocompetent adults; the majority presented with fever of unknown origin and abdominal pain. In most cases the causative organism was B. henselae and the pathological findings were necrotizing granulomas, similar to the pathological features in classic CSD. Concomitant endocarditis was diagnosed in one case. Because Bartonella is one of the leading pathogens of culture-negative endocarditis, we raise the question of whether a comprehensive evaluation for endocarditis is needed in cases of systemic CSD.

Fatal hepatic hemorrhage by peliosis hepatis in X-linked myotubular myopathy: a case report

We report a 5-year-old boy with X-linked myotubular myopathy complicated by peliosis hepatis. At birth, he was affected with marked generalized muscle hypotonia and weakness, which required permanent ventilatory support, and was bedridden for life. He died of acute fatal hepatic hemorrhage after using a mechanical in-exsufflator. Peliosis hepatis, defined as multiple, variable-sized, cystic blood-filled spaces through the liver parenchyma, was confirmed by autopsy. To avoid fatal hepatic hemorrhage by peliosis hepatis, routine hepatic function tests and abdominal imaging tests should be performed for patients with X-linked myotubular myopathy, especially at the time of using artificial respiration.

Peliosis hepatis due to disseminated tuberculosis in a patient with AIDS

Peliosis hepatis is a rare histopathological entity of unknown etiology. We present a case of peliosis hepatis in a 44-year-old man with disseminated tuberculosis and acquired immunodeficiency syndrome. The diagnosis of peliosis hepatis was based on liver biopsy results which were suggestive of tuberculous etiology. Diagnosis of tuberculosis was confirmed by auramine stain, rRNA amplification and culture of Mycobacterium tuberculosis from synovial fluid of the elbow joint. The patient responded favourably to tuberculostatic treatment with four drugs and the early initiation of highly active antiretroviral therapy. Histopathological evidence of peliosis hepatis, without an obvious cause, makes it necessary to rule out tuberculosis, especially in the context of immunodeficiency diseases and immigrants from endemic areas.

Surgical treatment of a patient with peliosis hepatis: A case report

This report describes a case of a space-occupying lesion in the right liver in a 38-year-old man who was found to have peliosis hepatis. Clinical data of this patient were presented, including medical history, laboratory test and imaging results, and postoperative pathological findings (hematoxylin and eosin staining). Review of his medical history showed that the patient had been bitten by a dog three years earlier. B-mode ultrasonography revealed an uneven echo mass in the right hemiliver, and magnetic resonance imaging scans also showed a mass in the anterior segment of the right liver. Upon surgical removal, the mass was found to be 4.0 cm × 3.8 cm × 3.8 cm in size and located in segment VI. The mass had a dark and soft appearance, with an irregular edge on intraoperative ultrasonography. Postoperative pathological findings revealed many small capsules filled with blood cells. The patient was diagnosed with peliosis hepatis based on his medical history of having been bitten by a dog, presence of mild anemia, and lack of characteristic symptoms, including fever of unknown origin, abdominal pain, and hepatosplenomegaly, combined with intraoperative and postoperative pathologic findings. The operation was successful, and after being treated with anti-infection agents, the patient had a good recovery.

Depolymerization of cytokeratin intermediate filaments facilitates intracellular infection of HeLa cells by Bartonella henselae

Bartonella henselae is capable of invading epithelial and endothelial cells by modulating the function of actin-dependent cytoskeleton proteins. Although understanding of the pathogenesis has been increased by the development of an in vitro infection model involving endothelial cells, little is known about the mechanism of interaction between B. henselae and epithelial cells. This study aims to identify the binding candidates of B. henselae in epithelial cells and explores their effect on B. henselae infection. Pull-down assays and mass spectrometry analysis confirmed that some of the binding proteins (keratin 14, keratin 6, and F-actin) are cytoskeleton associated. B. henselae infection significantly induces the expression of the cytokeratin genes. Chemical disruption of the keratin network by using ethylene glycol tetraacetic acid promotes the intracellular persistence of B. henselae in HeLa cells. However, cytochalasin B and phalloidin treatment inhibits B. henselae invasion. Immunofluorescent staining demonstrates that B. henselae infection induces an F-actin-dependent rearrangement of the cytoskeleton. However, we demonstrated via immunofluorescent staining and whole-mount cell electron microscopy that keratin intermediate filaments are depolymerized by B. henselae. The results indicate that B. henselae achieves an intracellular persistence in epithelial cells through the depolymerization of cytokeratin intermediate filaments that are protective against B. henselae invasion.

Bartonella henselae infections in solid organ transplant recipients: report of 5 cases and review of the literature

Bartonella henselae is the causative agent of cat scratch disease and bacillary angiomatosis-peliosis. The spectrum of disease, diagnosis, and management of B. henselae infection in solid organ transplant recipients has not been well characterized. We identified 29 cases of solid organ transplant recipients who had Bartonella infection, 24 by a review of the English-language literature and 5 from our institution. Localized cat scratch disease was found in 8 patients (28%), and disseminated infection was found in 21 patients (72%). The mean time after transplantation to development of Bartonella infection among those with cat scratch disease was 5.6 ± 5.3 years, and among those with disseminated infection was 2.7 ± 2.4 years. Prominent clinical features included cat exposure in 26 patients (90%), fever in 27 patients (93%), lymphadenopathy in 12 patients (41%), and skin lesions in 7 patients (24%). Methods used in establishing the diagnosis of Bartonella infection included culture, polymerase chain reaction (PCR) assay, serologic assays, and histopathologic examination. Culture was positive in 2 of only 4 patients in whom this was performed, and PCR was positive in 12 of 14 patients (86%) in whom this test was performed. Serologic assays were positive in all 23 patients who were tested. Histopathologic examination of tissues in all 8 patients who had cat scratch disease revealed granulomatous inflammation in 4 (50%) and bacillary angiomatosis-peliosis in 2 (25%). Among the 15 patients who had disseminated infection and who had tissue examined, 8 (53%) had only granulomatous inflammation, 4 had only bacillary angiomatosis-peliosis (27%), and 2 had both granulomas and bacillary angiomatosis-peliosis (13%). A positive Warthin-Starry or Steiner stain was noted in 12 of 19 patients (63%) who had 1 of these stains performed. All 8 patients with cat scratch disease and 19 of 21 patients with disseminated bartonellosis were cured with antimicrobial therapy. Two patients, both of whom had endocarditis, died. Among solid organ transplant recipients, infection with B. henselae is uncommon and has diverse disease manifestations including disseminated disease. Persistent fevers or lymphadenopathy in a transplant recipient who has been exposed to cats should prompt clinicians to maintain a high index of suspicion for B. henselae infection. Identifying B. henselae as the causative organism often requires multiple diagnostic studies. Once the diagnosis is established, most solid organ transplant recipients respond appropriately to antimicrobial treatment.

Cutaneous bacillary angiomatosis in renal transplant recipients: report of three new cases and literature review

Bacillary angiomatosis (BA) is a rare vasculoproliferative disorder due to Bartonella henselae (BH) or Bartonella quintana. It can involve many organs, including the skin, and has been mainly reported in patients with acquired immunodeficiency syndrome. In organ transplant recipients (OTR), this disorder remains misdiagnosed and therapeutic guidelines are nonexistent. We report 3 cases of BA with skin involvement in OTR and review similar cases from the literature. BA manifests on the skin with violaceous lesions mimicking Kaposi sarcoma, and is associated with fever, lymphadenopathy, and liver, spleen, or lung nodules. Bartonellosis infections in OTR are due to BH, the agent causing cat-scratch disease (CSD), but BA comprises histologically a prominent vascular proliferation, which is usually lacking in CSD. Cultures and serologic tests are poorly reliable for the diagnosis, which relies on demonstration of BH within the lesions. A history of cat exposure exists in most cases and pediatric OTR are at higher risk. Prevention consists of regular use of a flea-control product in cats and prompt cleaning of scratches. Our cases highlight several original features of this rare condition, which could potentially improve the management of BA in OTR.

Bartonella infection: treatment and drug resistance

Bartonella species, which belong to the α-2 subgroup of Proteobacteria, are fastidious Gram-negative bacteria that are highly adapted to their mammalian host reservoirs. Bartonella species are responsible for different clinical conditions affecting humans, including Carrion's disease, cat scratch disease, trench fever, bacillary angiomatosis, endocarditis and peliosis hepatis. While some of these diseases can resolve spontaneously without treatment, in other cases, the disease is fatal without antibiotic treatment. In this article, we discuss the antibiotic susceptibility patterns of Bartonella species, detected using several methods. We also provide an overview of Bartonella infection in humans and animals and discuss the antibiotic treatment recommendations for the different infections, treatment failure and the molecular mechanism of antibiotic resistance in these bacteria.

Liver disease in the HIV-infected individual

Since the advent of effective antiretroviral therapy (ART) for human immunodeficiency virus-1 (HIV), there has been a substantial decrease in deaths related to acquired immunodeficiency syndrome (AIDS). However, in the ART era, liver disease is now the most common non-AIDS-related cause of death among HIV-infected patients, accounting for 14%-18% of all deaths in this population and almost half of deaths among hospitalized HIV-infected patients. Just as the burden of non-AIDS morbidity and mortality has changed in the ART era, the types of liver disease the clinician is likely to encounter among these patients have changed as well. This review will discuss the causes of liver disease in the HIV-infected population in the ART era, including chronic hepatitis C virus, chronic hepatitis B virus, medication-related hepatotoxicity, alcohol abuse, nonalcoholic fatty liver disease, and AIDS-related liver diseases.

An immunocompromised murine model of chronic Bartonella infection

Bartonella are ubiquitous gram-negative pathogens that cause chronic blood stream infections in mammals. Two species most often responsible for human infection, B. henselae and B. quintana, cause prolonged febrile illness in immunocompetent hosts, known as cat scratch disease and trench fever, respectively. Fascinatingly, in immunocompromised hosts, these organisms also induce new blood vessel formation leading to the formation of angioproliferative tumors, a disease process named bacillary angiomatosis. In addition, they cause an endothelial-lined cystic disease in the liver known as bacillary peliosis. Unfortunately, there are as yet no completely satisfying small animal models for exploring these unique human pathologies, as neither species appears able to sustain infection in small animal models. Therefore, we investigated the potential use of other Bartonella species for their ability to recapitulate human pathologies in an immunodeficient murine host. Here, we demonstrate the ability of Bartonella taylorii to cause chronic infection in SCID/BEIGE mice. In this model, Bartonella grows in extracellular aggregates, embedded within collagen matrix, similar to previous observations in cat scratch disease, bacillary peliosis, and bacillary angiomatosis. Interestingly, despite overwhelming infection later in disease, evidence for significant intracellular replication in endothelial or other cell types was not evident. We believe that this new model will provide an important new tool for investigation of Bartonella-host interaction.

Gender Differences in Emerging Infectious Diseases

This chapter focuses on gender differences in emerging infectious diseases. An urgent worldwide threat is posed by the introduction and spread of novel infectious diseases. The reasons for emerging infectious diseases are numerous and complex. Among the most significant explanations for these emerging diseases are changes in environment and ecology caused by natural phenomena such as droughts, hurricanes, and floods; and human-made phenomena such as agricultural development, urbanization, and denuding of forests. Worldwide conflict, including wars, ethnic cleansing, and genocide, have led to displacement of large populations into overcrowded settlements where safe water is not available and sanitation is poor. For example, unsanitary conditions led to a huge increase in the rat population in post-war Kosovo, resulting in a tularemia outbreak with 327 confirmed cases in 8 months. Regional conflict leads to breakdown in infection control, inadequate surveillance, impeded access to populations, and spread of infectious diseases through movement of refugees and aid workers. Increased precipitation, a result of climate change, leads to more agricultural run-off, allowing pathogens to enter drinking water systems. In developing countries where poverty and inadequate infrastructure are the norm, public health monitoring systems must be supported and improved so that new or more severe risks to health can be identified and curtailed. As new infectious diseases are recognized, critical issues arise regarding pregnant women and their unborn children. Physiologic changes during pregnancy and gestational age both alter decision-making regarding vaccinations and medications.

[Bartonella henselae, an ubiquitous agent of proteiform zoonotic disease]

Bartonella henselae is the causative agent of cat scratch disease, a human infection usually characterized by persistent regional lymphadenopathy. It is transmitted to humans by cat scratches or bites. Cats are the major reservoir for this bacterium thus B. henselae has a worldwide distribution. The bacterial pathogenicity may bay emphasized by the immune status of the infected host. Angiomatosis or hepatic peliosis are the most frequent clinical manifestations in immunocompromised patients. B. henselae is also responsible for endocarditis in patients with valvular diseases, and may induce various clinical presentations such as: bacteriemia, retinitis, musculoskeletal disorders, hepatic or splenic diseases, encephalitis, or myocarditis. Several diagnostic tools are available; they may be combined and adapted to every clinical setting. B. henselae is a fastidious bacterium; its diagnosis is mainly made by PCR and blood tests. No treatment is required for the benign form of cat scratch disease. For more severe clinical presentations, the treatment must be adapted to every clinical presentation.

Bartonella quintana in body lice and head lice from homeless persons, San Francisco, California, USA

Bartonella quintana is a bacterium that causes trench fever in humans. Past reports have shown Bartonella spp. infections in homeless populations in San Francisco, California, USA. The California Department of Public Health in collaboration with San Francisco Project Homeless Connect initiated a program in 2007 to collect lice from the homeless to test for B. quintana and to educate the homeless and their caregivers on prevention and control of louse-borne disease. During 2007-2008, 33.3% of body lice-infested persons and 25% of head lice-infested persons had lice pools infected with B. quintana strain Fuller. Further work is needed to examine how homeless persons acquire lice and determine the risk for illness to persons infested with B. quintana-infected lice.

Isolation of Bartonella vinsonii subsp. berkhoffii genotype II from a boy with epithelioid hemangioendothelioma and a dog with hemangiopericytoma

In this report, we describe isolation of Bartonella vinsonii subsp. berkhoffii genotype II from a boy with epithelioid hemangioendothelioma and a dog with hemangiopericytoma. These results suggest that B. vinsonii subsp. berkhoffii may cause vasoproliferative lesions in both humans and dogs.

Immunogenicity of Bartonella henselae P26 in cats

Cat scratch disease (CSD) has an estimated prevalence of approximately 200,000 persons in the USA, and approximately 22,000 new cases occur annually. Cats are the natural carriers of Bartonella henselae, the agent for CSD. Zoonotic transmission of B. henselae can result in CSD in immunocompetent humans and bacillary angiomatosis in immunosuppressed humans. Infection in cats often goes undetected. Development of a vaccine to prevent feline infection is warranted to reduce the prevalence of infection in the feline population and to decrease the potential for zoonotic transmission. One of the immunoreactive proteins identified from our previous study was P26. In this study, we demonstrated that B. henselae recombinant P26 (rP26) was immunogenic in cats. Four cats immunized with rP26 and four control cats were challenged with B. henselae type I and blood samples were collected for culture, PCR, and serology. Immunization with rP26 did not provide protection against B. henselae infection in cats at the doses used in this study. However, p26 PCR proved to be more sensitive for detection of infection in cats compared to gltA PCR. Furthermore, ELISA using rP26 as the substrate was more sensitive than ELISA using B. henselae type I outer membrane proteins.

[The diagnosis of cat-scratch-disease-associated adenitis: diagnostic value of serology and polymerase chain reaction]

The diagnosis of cat scratch disease (CSD) associated adenitis relies classically on the association of clinical, epidemiological and bacteriological criteria. The polymerase chain reaction (PCR) looks like a more competitive diagnostic trial than serology. We evaluated the sensitivity, specificity and predictive positive and negative values of serology in routine diagnosis of CSD. A retrospective study over five years was led among patients presenting a suspicion of CSD and having a serology and/or a PCR. The Gold standard for diagnosis was PCR. The serological tests of Bartonella henselae was performed once in 482 patients, of which 2% (11 out of 482) were positive, and twice in only 39 patients (8%). The PCR diagnosis method for B. henselae was performed in biopsy of specimen lymph nodes in 28 patients and 14 out of 28 were positive. In nine patients, the diagnosis was exclusively made by PCR. Among the 14 patients whose PCR was negative, two had a positive serology and in three others patients, the serology was not performed. The sensitivity of serology was 35%, this confirms the low sensitivity of the serology in the CSD diagnosis. The diagnosis was confirmed in 56% of cases where PCR was performed. This led us to propose to perform systematically the PCR test for B. henselae in case of adenitis possibly associated with CSD.

[Pathology along the liver sinusoids: endothelial and perisinusoidal findings]

Sinusoidal alterations unrelated to primary hepatocellular damage present without characteristic clinical findings and in these cases the liver biopsy is particularly important. Capillarization of sinusoids is characterized by closing of fenestration, formation of a basal membrane and by the expression of CD34 and is typical for active cirrhosis. In nodular regeneratory hyperplasia, capillarization indicates a local or general disturbance of perfusion. In large regenerative nodules, focal nodular hyperplasia and liver cell adenoma CD34-positive capillaries reflect afferent parts and CD34-negative sinusoids the efferent parts of the parenchymal vascular bed. HCC generally have a completely capillarized CD34-positive vascular bed. Hepatic angiosarcomas and epithelioid hemangioendotheliomas can be easily overseen in liver biopsies, if they spread along the sinusoids without detoriation of the acinar architecture and without significant alteration of the surrounding liver cell plates. Toxic damage of endothelial cells, post-sinusoidal stasis and sinusoidal hyperperfusion are the underlying pathogenetic principles of sinusoidal injury. Rupture and loss of the perisinusoidal reticulin fibres lead to peliosis hepatis. In these cases liver biopsy might disclose occlusion of the terminal liver veins (VOD). Perisinusoidal fibrosis can be caused by intrasinusoidal accumulation of pathologic cells, advanced intrasinusoidal macrophagocytic storage diseases and by activation of the vitamin A-storing hepatic stellate cells. Perisinusoidal amyloidosis can be the first sign of an underlying B-cell neoplasia.

Bacillary angiomatosis in an HIV-positive man with multiple risk factors: A clinical and epidemiological puzzle

A 36-year-old man with advanced AIDS presented with skin lesions, fever and weight loss. Physical examination revealed skin lesions suggestive of bacillary angiomatosis. Diagnostic imaging identified bone lesions, soft tissue masses and a single hepatic lesion. His clinical presentation was most consistent with Bartonella quintana; however, his risk for infection with B quintana was limited to a remote, brief period of homelessness. In contrast, his frequent contact with cats presented substantial potential exposure to Bartonella henselae.Diagnosing a Bartonella infection presents challenges. The detection of bacteremia is hindered by slow growth in BACTEC media (BD Diagnostic Systems, Canada). In the present case, recovery of the organism required blind subcultures after at least eight days of incubation. Speciation by 16s ribosomal RNA analysis confirmed B quintana as the pathogen.Because the patient presented with skin lesions, the diagnosis was straightforward; however, skin lesions are nondiagnostic in some cases. Microbiological confirmation of the diagnosis rests on sufficient clinical suspicion to apply labour-intensive laboratory protocols.

Cat scratch disease causing hepatic masses after liver transplant

Hepatic cat scratch disease is rarely reported in liver transplant recipients and has never been reported with discrete liver lesions in the graft. A 52-year-old woman was transplanted for hepatitis C cirrhosis and hepatocellular carcinoma. Her posttransplant course was uneventful. She presented 2.7 years after transplantation with fever of unknown origin and went on to develop multiple and diffuse discrete liver lesions. Despite an extensive work-up including percutaneous and laparoscopic biopsies, a subsegmental resection that included one of these masses was required to make the diagnosis of Bartonella henselae infection. Serologic tests were equivocal. Histology was consistent with cat scratch disease of the liver, and polymerase chain reaction (PCR) testing of the resected tissue confirmed the diagnosis. Response to doxycycline was rapid. Fevers resolved within 7 days. Repeat abdominal CT scan showed reduction of the liver masses. Cat scratch disease should be considered in postliver transplant patients presenting with fever and liver lesions, especially if close contact with cats has occurred. Diagnosis by PCR testing of involved tissue is preferred when serologies are equivocal due to immunosuppression.