Recommendations for treatment of human infections caused by Bartonella species

Arthropod-borne diseases in homeless

Homeless people are particularly exposed to ectoparasite. The living conditions and the crowded shelters provide ideal conditions for the spread of lice, fleas, ticks, and mites. Body lice have long been recognized as human parasites and although typically prevalent in rural communities in upland areas of countries close to the equator, it is now increasingly encountered in developed countries especially in homeless people or inner city economically deprived population. Fleas are widespread but are not adapted to a specific host and may occasionally bite humans. Most common fleas that parasite humans are the cat, the rat, and the human fleas, Ctenocephalides felis, Xenopsylla cheopis, and Pulex irritans, respectively. Ticks belonging to the family Ixodidae, in particular, the genera Dermacentor, Rhipicephalus, and Ixodes, are frequent parasites in humans. Sarcoptes scabiei var. hominis is a mite (Arachnida class) responsible for scabies. It is an obligate parasite of human skin. The hematophagic-biting mite, Liponyssoides sanguineus, is a mite of the rat, mouse, and other domestic rodents but can also bite humans. Finally, the incidence of skin disease secondary to infestation with the human bedbug, Cimex lectularius, has increased recently. Bacteria, such as Wolbacchia spp. have been detected in bedbug. The threat posed by the ectoparasite in homeless is not the ectoparasite themselves but the associated infectious diseases that they may transmit to humans. Except for scabies all these ectoparasites are potential vectors for infectious agents. Three louse-borne diseases are known at this time. Trench fever caused by Bartonella quintana (B. quintana), epidemic typhus caused by Rickettsia prowazekii, and relapsing fever caused by the spirochete Borrelia recurrentis. Fleas transmit plague (Xenopsylla cheopis and Pulex irritans), murine typhus (Xenopsylla cheopis), flea-borne spotted rickettsiosis on account of the recently described species Rickettsia felis (C. felis), and occasionally cat scratch disease on account of Bartonella henselae (C. felis). The role of fleas as potential vector of B. quintana has recently been suggested. Among the hematophagic-biting mites, L. sanguineus, is responsible for the transmission of Rickettsia akari, the etiologic agent of rickettsialpox. Virtually, no data are available on tick-borne disease in this population. This article will deal with epidemiology, diagnosis, prevention, and treatment of these ectoparasite and the infectious diseases they transmit to the homeless people.

Cloning, characterization, and expression of Bartonella henselae p26

In order to identify immunoreactive Bartonella henselae proteins, B. henselae antiserum from an experimentally infected cat was used to screen a B. henselae genomic DNA expression library. One immunoreactive phage clone contained a gene (p26) with significant nucleotide identity with orthologs in brucellae, bartonellae, and several plant-associated bacteria. p26 gene sequences from four B. henselae strains, one B. koehlerae strain, and one B. clarridgeiae strain were cloned. Comparative nucleotide sequence analysis showed that p26 is a potential marker for molecular diagnosis of infection, as well as for identification to species level and genotyping of Bartonella sp. isolates. Alignment of the predicted amino acid sequences illustrated conserved putative protein features including a hydrophobic transmembrane region, a peptide cleavage site, and four dominant antigenic sites. Expression of p26 in Escherichia coli produced two proteins (26 and 27.5 kDa), both of which were reactive with feline anti-B. henselae antisera. Furthermore, murine hyperimmune serum raised against either recombinant protein reacted with both proteins. No reactivity to either recombinant protein was detected in nonimmune serum, and reactivity persisted as long as 20 weeks for one cat. The p26 protein product is an immunodominant antigen that is expressed during infection in cats as a preprotein and is subsequently cleaved to form mature P26.

Molecular characterization of resistance to macrolides in Bartonella henselae

We selected in vitro erythromycin-resistant strains of Bartonella henselae. The mutants obtained had point mutations in domain V of 23S rRNA and/or in ribosomal protein L4. One lymph node of a patient with cat-scratch disease had such a mutation in 23S rRNA, suggesting that natural resistant strains may infect humans.

Atteinte hépatosplénique de la maladie des griffes du chat : à propos de deux observations chez l'immunocompétent

INTRODUCTION

Cat-Scratch Disease (CSD) is a well-recognized benign cause of localized lymphadenopathy, which often recovers spontaneously. However systemic clinical presentations are described in immunodeficient adults (bacillary angiomatosis, bacillary splenitis) and are less common in immunocompetent ones.

EXEGESIS

We report two cases of disseminated CSD in immunocompetent patients, presenting hepatosplenic nodules, associated in the second case with an endocarditis.

CONCLUSION

Bartonella serology must be achieved in case of hepatosplenic nodules with fever. Treatment of disseminated CSD in immunocompetent adults is still empirical and recovery can occur without antibiotherapy when endocarditis is not associated.

[Endocarditis due to Bartonella spp. Three new clinical cases and Spanish literature review]

INTRODUCTION

Infections by Bartonella spp. include a wide spectrum of emerging and re-emerging infectious diseases, such as culture-negative endocarditis.

METHODS

Description of 3 cases of endocarditis due to Bartonella spp. and review of those previously reported in Spain.

RESULTS

Including these 3 new cases of endocarditis due to Bartonella spp., a total of 6 cases have been reported in Spain. The median age of the patients was 51.6 years and 83.3% were men. There was history of contact with cats in 66.7%, and 50% were alcoholic. Only one patient had prior valvular disease. There were no clinical manifestations typical to any of the Bartonella species. The aortic valve was the one most commonly affected. In all cases, B. henselae was the agent implicated. The diagnosis was made by serology in 5 cases (83.3%). The outcome was favorable in all patients, although 4 of them (66.7%) required valve replacement.

CONCLUSION

Endocarditis due to Bartonella spp. is present in Spain and is likely to be underestimated. We should suspect this pathogen in patients with negative blood cultures and a history of chronic alcoholism, homeless patients, and those who have had contact with cats or who have been bitten by fleas or lice, as well as patients with endocarditis and positive serology against Chlamydia spp.

Disseminated Bartonella infection following liver transplantation*

Bartonella henselae has not only been identified as the causative agent of cat scratch disease, but it is also associated with other significant infectious syndromes in the immunocompromised population. We describe two cases of B. henselae associated diseases in liver transplant recipients who both had contact with cats. The first recipient developed localized skin manifestation of bacillary angiomatosis in association with granulomatous hepatitis. He tested positive for Immunoglobulin G (IgG) antibodies against B. henselae. The second patient developed axillary lymphadenopathy, with biopsy showing necrotizing granulomatous inflammation and polymerase chain reaction studies were positive for B. henselae DNA. Her serology for bartonellosis showed a fourfold rise in antibody titers during her hospitalization. Both patients responded to treatment with Azithromycin in combination with Doxycycline. These were the only cases within a series of 467 consecutive liver transplants performed in 402 patients performed during a 4-year period. Although bartonellosis is a rare infection in liver transplantation recipients, it should always be included in the differential diagnosis of patients presenting with fever, central nervous system (CNS) symptoms, skin lesions, lymphadenopathy, and hepatitis especially if prior contact with cats is reported.

Bartonella spp. in pets and effect on human health

Pets represent a large reservoir for human infection.

Among the many mammals infected with Bartonella spp., pets represent a large reservoir for human infection because most Bartonella spp. infecting them are zoonotic. Cats are the main reservoir for Bartonella henselae, B. clarridgeiae, and B. koehlerae. Dogs can be infected with B. vinsonii subsp. berkhoffii, B. henselae, B. clarridgeiae, B. washoensis, B. elizabethae, and B. quintana. The role of dogs as an important reservoir of Bartonella spp. is less clear than for cats because domestic dogs are more likely to be accidental hosts, at least in nontropical regions. Nevertheless, dogs are excellent sentinels for human infections because a similar disease spectrum develops in dogs. Transmission of B. henselae by cat fleas is better understood, although new potential vectors (ticks and biting flies) have been identified. We review current knowledge on the etiologic agents, clinical features, and epidemiologic characteristics of these emerging zoonoses.

Multifocal osteomyelitis in a child: a rare manifestation of cat scratch disease: a case report and systematic review of the literature

We present a case of a 9-year-old immunocompetent girl who presented with pain in her left elbow and a painful swelling at her left clavicle. She had no lymphadenopathy or fever. Four hot spots were seen at her left clavicle, proximal and distal left humerus and lumbo-sacral spine on a bone scan. A magnetic resonance imaging showed an inflammatory process with bone destruction at her clavicle. Serological testing and polymerase chain reaction performed on a bone biopsy identified a Bartonella henselae infection. She was treated with rifampin and trimethoprim-sulphamethoxazole. After a relapse half a year later, the patient recovered fully. Multifocal osteomyelitis is a rare manifestation of cat scratch disease in children.

Broad-range polymerase chain reaction for the diagnosis of Bartonella henselae endocarditis

We present a case of subacute bacterial endocarditis in a 10-year-old girl with Di-George syndrome, congenital heart disease, and mild immunodeficiency. She was afebrile at initial presentation but was found to have massive splenomegaly, and signs of congestive heart failure. No causative organism could be identified on routine blood and tissue cultures. A detailed clinical history revealed a history that she had been scratched by a cat and developed intermittant fevers over 3 months. Bartonella henselae was identified by broad-range 16S r-DNA polymerase chain reaction on valvular tissue specimens.

Bartonella quintana characteristics and clinical management

The pathogen is reemerging in the United States and Europe and is responsible for a number of clinical conditions.

Bartonella quintana, a pathogen that is restricted to human hosts and louse vectors, was first characterized as the agent of trench fever. The disease was described in 1915 on the basis of natural and experimental infections in soldiers. It is now recognized as a reemerging pathogen among homeless populations in cities in the United States and Europe and is responsible for a wide spectrum of conditions, including chronic bacteremia, endocarditis, and bacillary angiomatosis. Diagnosis is based on serologic analysis, culture, and molecular biology. Recent characterization of its genome allowed the development of modern diagnosis and typing methods. Guidelines for the treatment of B. quintana infections are presented.

Antimicrobial susceptibility of Bartonella henselae using Etest methodology

OBJECTIVES

Bartonella henselae is a fastidious slow growing pathogen which is seldom cultured in the laboratory. Previous descriptions of antimicrobial susceptibility have been largely limited to feline isolates and/or laboratory reference strains, with no accounting for genotypic or phenotypic diversity.

METHODS

An optimal method of antimicrobial susceptibility testing by Etest was established to compare the antimicrobial susceptibilities of 12 different isolates of B. henselae, 5 human and 7 feline, which have previously been well characterized by 16S rRNA sequencing, multi-locus sequence typing (MLST), phase variation and passage number.

RESULTS

No difference in susceptibility could be attributed to differences in genotype, source of the isolate or passage number. Where comparisons were drawn with previously published results, these were found to be concordant.

CONCLUSIONS

We conclude that antibiotic susceptibility can be determined by a simple Etest method for B. henselae isolates. This method is reproducible among diverse strains, and is sufficiently predictable that generalizations can be confidently made about optimal antibiotic choices.

Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America

BACKGROUND

Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness.

METHODS AND RESULTS

This work represents the third iteration of an infective endocarditis "treatment" document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen.

CONCLUSIONS

The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.

The Expanded Spectrum of Bartonellosis in Children

Bartonella spp cause various clinical syndromes immunocompetent and immunocompromised hosts. Domestic cats are the natural reservoir, and vectors of B henselae. B henselae infection usually occurs early in childhood, is generally asymptomatic, and in most cases revolves spontaneously. It may, however, produce a wide spectrum of clinical symptoms, the most frequent feature being cat-scratch disease. Disseminated atypical B. henselae infection may follow cat-scratch disease alter a symptom-free period or may present de novo mimicking a wide range of clinical disorders. A careful clinical history researching an intimate contact with a kitten associated with a specific serology and an abdominal ultrasound for typical hepatosplenic involvement may follow a rapid and accurate diagnosis.

Enfermedades producidas por Bartonella spp

The genus Bartonella is cause of a broad number of emerging and re-emerging infectious diseases. Clinical manifestations depend on the implicated Bartonella sp. and the immunity of the host. Because there is not a universal therapy for this infection, treatment should be chosen individually. Bartonella sp. is responsible of potentially serious clinical pictures (endocarditis, chronic bacteremia, bacillary angiomatosis, Carrion's disease, etc.), so clinical suspicion, a quick diagnosis and an early treatment provide a better resolution.

Cat-Scratch Disease (Ocular Bartonellosis) Presenting as Bilateral Recurrent Iridocyclitis

An otherwise healthy 9-year-old girl presented with bilateral recurrent anterior uveitis. Thirteen months later, the diagnosis of cat-scratch disease (ocular bartonellosis) was suspected when neuroretinitis appeared. Confirmation was based on serological test results positive for Bartonella henselae. Antibiotic treatment completely cured the disease, and there have been no further manifestations during a follow-up period of 6 years.