Bartonella henselae infection induces a persistent mechanical hypersensitivity in mice.

Bartonella spp. are re-emerging and neglected bacterial pathogens. The natural reservoirs for several species of this genus are domestic animals such as cats and dogs, the most common pets in the USA and Brazil. Some cat studies suggest that the infection is more prevalent in tropical and poverty-stricken areas. These bacteria were associated with a wide spectrum of clinical manifestations: fever of unknown origin, endocarditis, angiomatosis, chronic lymphadenopathy, hepatitis, fatigue, paresthesia and pain. Our group has already demonstrated that B. henselae -infected sickle cell disease mice present with hyperalgesia. We hypothesized that even immunocompetent mice infected by B. henselae would show an increased and persistent mechanical sensitivity. Five ten-week old male BALB/c mice were intraperitoneally inoculated with a 30 µL of suspension containing 10 4 CFU/mL of B. henselae, while five others were inoculated with an equal volume of saline solution. Four days after bacterial inoculation, the mechanical paw withdrawal threshold was measured using von Frey filaments in all animals, for five consecutive days. The infected animals showed hypersensitivity to mechanical stimuli for five consecutive days. The present study has demonstrated that B. henselae infection induces persistent mechanical hypersensitivity, a signal consistent with pain.

Prevalence of Bartonella spp. Infection in Patients with Sickle Cell Disease.

Background: The inherent characteristics of the sickle cell disease (SCD), the most common genetic hematological disorder, increase the propensity of infections. Bartonella spp. are emerging and neglected bacteria. A large spectrum of clinical manifestations has been linked to bartonella bloodstream infection in the last two decades that can cause fatal outcomes, especially in immunodeficient patients. The goal of this study was to evaluate the prevalence of bartonella infection in SCD patients. Materials and Methods: We evaluated Bartonella spp. prevalence in 107 SCD patients. Blood samples and enrichment blood cultures were analyzed by molecular detection of Bartonella spp. DNA. Bartonella DNA was amplified using conventional genus-specific Bartonella PCR which amplifies the Intergenic Transcribed Spacer region and Bartonella henselae-specific nested PCR which amplifies the FtsZ gene. Positive patient DNAs were tested with ssrA conventional PCR. All amplicons were sequenced. Findings: Ten of 107 patients tested positive for B. henselae infection in at least one molecular test. All obtained amplicons were sequenced and similar to B. henselae sequences deposited in GenBank (accession number BX897699). Based on statistical results, bloodstream infection with B. henselae was not associated with animal contact or blood transfusions. Conclusion: We detected B. henselae DNA in 10 (9.3%) SCD studied patients. These patients were notified and treatment was offered to them.

Histomorphometric approach to differentiate skin lesions of tuberculoid leprosy from sarcoidosis.

BACKGROUND: More than 200 000 new cases of leprosy are detected worldwide annually. Physicians commonly have difficulty in differentiating tuberculoid form of leprosy (TL) from sarcoidosis' cutaneous manifestation. METHODS: Skin biopsies of 33 patients with TL and 24 with sarcoidosis were reviewed on hematoxylin and eosin- and Gomori-stained sections, in order to find reliable criteria for distinguishing one disease from another. RESULTS: Nine of the 24 features analyzed presented significant predictive value for diagnosis (P < .05). Predominance of tuberculoid granulomas in adnexal and neural distribution, and granulomas replacing the nerves localized within sweat gland glomeruli were predictive to TL diagnosis. For sarcoidosis, dermal fibrosis, back-to-back distribution of the granulomas, presence of atypical giant cells and plasma cells, greater number of conventional giant cells, and spared nerves beside the granuloma were predictive criteria. The median surface density of reticulin fibers was significantly higher in sarcoidosis (3.44) than in TL (2.99). Nonetheless, using logistic regression, this variable did not discriminate between the diseases (P = .096). CONCLUSIONS: Isolated histological features are not fully predictive to differentiate the 2 diseases. However, those with statistical value can assist this distinction in diagnostic practice. Although the results of the analysis of the reticulin fibers density did not tell apart TL from sarcoidosis, they corroborate the idea of fiber fragmentation within tuberculoid leprosy granulomas, reiterating the importance of morphometry in the histological examination.

Acute and Late Bartonella henselae Murine Model Infection.

Bartonella spp. are fastidious gram-negative neglected bacilli with worldwide distribution. They are able to cause intraerythrocytic and potentially fatal infection. Cats and dogs are reservoirs of some species of these agents. Blood-sucking arthropods are potential vectors. Our aim was to evaluate the blood, skin, liver, and spleen in BALB/c mice by using molecular tests and confocal microscopy to demonstrate Bartonella henselae infection in the bloodstream and organs after 4 and 21 days of intraperitoneally injected bacterial suspension. We demonstrate that the occurrence of infection in organs precedes the detectable infection in blood. Therefore, late manifestation in blood may be another challenge in early detection and diagnosis of B. henselae infection.

Bartonella henselae transmission by blood transfusion in mice.

BACKGROUND: Bartonella spp. are neglected fastidious Gram-negative bacilli. We isolated Bartonella henselae from 1.2% of 500 studied blood donors and demonstrated that the bacteria remain viable in red blood cell units after 35 days of experimental infection. Now, we aim to evaluate the possibility of B. henselae transmission by blood transfusion in a mouse model. STUDY DESIGN AND METHODS: Eight BALB/c mice were intraperitoneal inoculated with a 30 µL of suspension with 10(4) CFU/mL of B. henselae and a second group of eight mice were inoculated with saline solution and used as control. After 96 hours of inoculation, the animals were euthanized. We collected blood and tissue samples from skin, liver, and spleen. Thirty microliters of blood from four Bartonella-inoculated animals were transfused into a new group (n = 4). Another group received blood from the control animals. B. henselae infection was investigated by conventional and nested polymerase chain reaction (PCR). RESULTS: Blood samples from all 24 mice were negative by molecular tests though half of the tissue samples were positive by nested PCR in the intraperitoneal Bartonella-investigated animals. Tissues from two of the four mice that received blood transfusions from Bartonella-inoculated animals were also nested PCR positives. CONCLUSIONS: Transmission of B. henselae by transfusion is possible in mice even when donor animals have undetectable bloodstream infection. The impact of human Bartonella sp. transmission through blood transfusion recipients must be evaluated.

p53 immunoexpression in stepwise progression of cutaneous squamous cell carcinoma and correlation with angiogenesis and cellular proliferation.

Multistep carcinogenesis involves loss of function of tumor suppressor proteins such as p53 and induction of angiogenesis. Such mechanisms contribute to cutaneous squamous cell carcinoma progression and may be interconnected. We aimed to explore p53 immunoexpression in spectral stages of cutaneous squamous cell carcinoma and correlate expression to both neovascularization and cellular proliferation. We estimated the percentages of immunostained cells for p53 and Ki67 (proliferation marker) in three groups: 23 solar keratoses, 28 superficially invasive squamous cell carcinomas and 28 invasive squamous cell carcinomas. The Chalkley method was used to quantify the microvascular area by neoangiogenesis (CD105) immunomarker in each group. There was no significant difference for rate of p53- and Ki67-positive cells between groups. Significant positive correlation was found between the CD105 microvascular area and the rate of p53 positive cells in superficially invasive squamous cell carcinoma as well as between the rate of p53- and Ki67-positive cells in invasive squamous cell carcinoma. p53 and Ki67 immunoexpression did not increase with cutaneous squamous cell carcinoma progression. Neovascularization in the initial stage of invasion and proliferative activity in the frankly invasive stage were both associated with p53 immunoexpression. Loss of p53 tumor suppressor function through progressive steps may be directly involved in skin carcinogenesis.

Bartonella clarridgeiae bacteremia detected in an asymptomatic blood donor.

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.

Perforin and granzyme B involvement in oral lesions of lichen planus and chronic GVHD.

BACKGROUND: Oral lesions of lichen planus and chronic graft-vs.-host disease (cGVHD) have similar clinical and histological features, but distinct etiology. Apoptosis induced by cytotoxic T lymphocyte has been proposed as a mechanism of keratinocytes death. Cytotoxicity can be mediated by granules containing granzyme B and perforin. Since common features can reflect similarities in immunological mechanisms, we studied the role of those molecules in both diseases. METHODS: We analyzed 29 cases of oral lichen planus and 27 of oral cGVHD. The sections were studied on H&E, perforin and granzyme B staining. RESULTS: The total means (epithelium plus connective tissue number) of the granzyme B- and perforin-positive cells were significantly higher in cGVHD than in oral lichen planus lesions (P<0.05). Also, it was found that the higher the number of perforin+ cells, the higher the number of granzyme-B+ cells in the epithelium and in the connective tissue for both groups (P < 0.05). In oral lichen planus, the number of single apoptotic bodies had a positive correlation with connective tissue granzyme immunostaining and a negative correlation with perforin (P<0.01). On the contrary, in oral cGVHD, the number of apoptotic body clusters presented a positive correlation with connective tissue perforin (P<0.01). CONCLUSIONS: Our findings indicate that apoptosis in oral lichen planus seems to be correlated with granzyme B release, while in oral cGVHD, perforin seems to be more important. Although these diseases present clinical and histological similarities, subtle differences seem to exist in their pathogenetic mechanisms.