Extra-Aortic Mycotic Aneurysm Due to Group A Streptococcus after Pharyngitis

Mycotic aneurysms, especially outside the aorta, are uncommon, with group A Streptococcus a particularly rare cause. We report a case of extra-aortic mycotic aneurysm following a sore throat without demonstrable bacteremia where identification of the pathological organism was made by molecular diagnostic techniques after a standard laboratory culture was negative.     

Mycotic Keratitis Due to Aspergillus nomius

We report the first known case of fungal keratitis caused by Aspergillus nomius. Ocular injury was known as a predisposing factor. The patient was treated with natamycin and econazole eye drops, itraconazole eye ointment, and oral ketoconazole. A therapeutic penetrating keratoplasty was performed 16 days after presentation. A sequence-based approach was used to assign the isolate to a species.     

Mycotic Aneurysm Caused by Streptococcus constellatus subsp. constellatus

An infected mycotic aneurysm due to Streptococcus constellatus subsp. constellatus has not previously been reported. We report on this condition in an 87-year-old woman who had aggravating abdominal pain and a large fusiform aneurysm over the thoracic-abdominal aorta with mural thrombus. Isolates from two sets of blood cultures and the debrided tissue were identified as S. constellatus subsp. constellatus by their biochemical reaction profiles, compatible 16S rRNA gene sequencing results, and sequencing results for the partial groESL gene and the 16S-23S intergenic spacer region.     

Complete Factor I Deficiency Due to Dysfunctional Factor I with Recurrent Aseptic Meningo-Encephalitis

Purpose

Complement regulators control the activated complement system. Defects in this homeostasis can result in tissue damage and autoimmune diseases with a heterogeneity in clinical presentation. Complement factor I (FI), a serine protease, is an important regulator of alternative pathway activation. We report a diagnostic work-up of a patient with relapsing inflammatory mediated meningo-encephalitis. Our work-up revealed a rare genetic factor I (FI) deficiency. So far, all cases of reported complete factor I deficiency have absent serum levels of FI. We present here a unique case of a complete factor I deficiency based on a functional FI defect.

Methods

Complement assays and measurement of FI activity were performed in the patient, her family, factor H-deficient patients, a patient with C3-nephritic factor and 11 healthy controls. Genetic sequencing of the FI coding regions in the patient and her parents was performed.

Results

The patient had absent alternative pathway activity with low levels of C3 and normal serum level of FI. The patient’s plasma FI did not degrade C3b, with normalisation of C3b degradation after adding purified FI. Mutation analysis of the complement factor I gene revealed two heterozygous mutations (I322T and D506V).

Conclusion

To our knowledge, this paper describes a complete FI deficiency caused by a defect of FI activity for the first time. Normal FI concentration does not exclude a complete FI defect, additional functional analysis of FI is required in any patient with a defect of complement activation. Recurrent aseptic meningo-encephalitis is a rare clinical presentation of complete FI deficiency.     

Cardiac Tamponade Due to Rupture of a Subepicardial Aneurysm Following Myocardial Infarction

A 71 year old male died of cardiac tamponade due to cardiac rupture 22 days after onset of acute myocardial infarction. Autopsy revealed rupture of an unusual ventricular aneurysm characterized by abrupt interruption of the myocardium, a narrow neck, a thin fibrous outer wall partially showing myocardial fibers, and lack of adhesion between the epicardium and pericardium. A review of the literature revealed that 11 among 32 autopsy cases of false aneurysm showed a similar morphology to the present case, these being classifiable as subepicardial aneurysm. Acta Pathol Jpn 41: 52 58, 1991.     

Cytokine response of T-cell subsets from Brucella abortus-infected mice to soluble Brucella proteins.

Hot saline extracts of Brucella abortus 19 were separated by successive differential precipitation with 50 and 70% ammonium sulfate, yielding fractions SBP50, with predominantly 36-kDa proteins and a number of medium-sized proteins (26 to 33 kDa), and SBP70, with 14-kDa and lower-molecular-mass proteins. Both fractions stimulated specifically proliferation and cytokine production by spleen cells from brucella-infected mice, although the activity of SBP50 was much higher than that of SBP70. Further separation of SBP50 by a DEAE-Sepharose column resulted in three distinct subfractions which were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The three subfractions were analyzed for their abilities to induce lymphocytes to proliferate and produce cytokines. The three subfractions were all active but with characteristic differences in magnitude. Subfraction 1 stimulated moderate proliferation, high interleukin 6 (IL-6) production, and relatively low production of gamma interferon (IFN-gamma). Subfraction 2 was the strongest stimulus for proliferation and production of IL-6 and IFN-gamma, while subfraction 3 stimulated moderate cell proliferation, a high level of IFN-gamma, and a low level of IL-6. IL-2 production stimulated by the three subfractions was similar. SBP50 and all three subfractions stimulated purified T cells of both CD4+ and CD8+ subsets to produce IFN-gamma. The production of IFN-gamma by CD8+ T cells to brucella antigens was enhanced with exogenous IL-2.     

Interleukin-10 downregulates protective immunity to Brucella abortus.

In vivo neutralization of interleukin-10 (IL-10) with an anti-IL-10 monoclonal antibody resulted in up to 10-fold fewer bacteria in the spleens of BALB/c mice infected with the virulent Brucella abortus strain 2308. In vitro neutralization of endogenous IL-10 in brucella antigen-stimulated cultures of splenocytes from infected mice resulted in increased gamma interferon production in these cultures, whereas exogenous recombinant IL-10 inhibited the ability of peptone-elicited peritoneal macrophages to control intracellular brucellae. These data suggest that IL-10 may be downregulating the immune response to B. abortus by affecting both macrophage effector function and the production of the protective Th1 cytokine gamma interferon.     

Enzyme-linked immunosorbent assay with major outer membrane proteins of Brucella melitensis to measure immune response to Brucella species.

We developed an enzyme-linked immunosorbent assay (ELISA) system to measure human immunoglobulin G (IgG) and IgM response to the major outer membrane proteins of Brucella melitensis. The ELISA was more sensitive in detecting antibody than a standard microagglutination (MA) test with B. abortus antigen. Of 101 sera from persons with suspected brucellosis, 79 (78.2%) gave ELISA IgM titers greater than or equal to the B. abortus MA titer without 2-mercaptoethanol (2ME), which measures both IgM and IgG. Of the 101 sera, 97% gave ELISA IgG titers greater than or equal to the MA with 2ME titer. A total of 58 sera, drawn from 11 human patients from 1 to 29 weeks after onset of brucellosis, gave higher geometric mean titers for the ELISA IgG test than for the MA with 2ME test. These 58 sera also gave ELISA IgM geometric mean titers that were greater than or within one doubling dilution of the geometric mean titers of MA without 2ME. In addition to detecting antibody response to B. abortus, B. melitensis, and B. suis, the ELISA was sensitive to antibody response to human and canine infections with B. canis. The B. canis antibody response is not detected by the MA test with B. abortus antigen. The ELISA, with a standard preparation of major outer membrane proteins of B. melitensis as antigen, appears to be useful in measuring antibody response in humans to infections by all species of Brucella known to infect humans.     

Immunological response to the Brucella abortus GroEL homolog.

Western blot (immunoblot) analysis of sera from cattle vaccinated with Brucella abortus S19 exhibit an elevated serologic response to Hsp62, the GroEL homolog (BaGroEL). Serologic screening of individual cows vaccinated with B. abortus S19 revealed no correlation between the immune response to BaGroEL and protection against a challenge with virulent organisms. The humoral immune response to BaGroEL was restricted to a region of the mature protein which mapped to amino acids 317 to 355 and may represent a useful diagnostic tool for monitoring exposure to B. abortus. Immunity to a challenge with virulent B. abortus S2308 was not observed in the BaGroEL vaccinated mouse model.     

Different responses of macrophages to smooth and rough Brucella spp.: relationship to virulence

By comparing smooth wild-type Brucella strains to their rough mutants, we show that the lipopolysaccharide (LPS) O side chain of pathogenic Brucella has a dramatic impact on macrophage activation. It favors the development of virulent Brucella by preventing the synthesis of immune mediators, important for host defense. We conclude that this O chain property is firmly linked to Brucella virulence.     

Bacteremia Due to Cedecea neteri sp. nov

Three of four blood cultures from a patient with possible endocarditis were positive for a new species of Enterobacteriaceae which is named Cedecea neteri. This is the first reported case of bacteremia caused by a strain of Cedecea.     

Blastogenic response of bovine lymphocytes to Brucella abortus lipopolysaccharide.

Brucella abortus lipopolysaccharide was tested in a blastogenesis assay with unfractionated and nylon wool-separated peripheral blood lymphocytes of Brucella-naive cattle and cattle immunized with B. abortus. Our results indicated that in cattle the lipopolysaccharide of B. abortus is not a B-cell mitogen. In immunized animals it stimulated predominantly nylon wool-adherent cells. The lipopolysaccharide of Escherichia coli O128:B12, in contrast, induced a substantially greater proliferative response in circulating lymphocytes, predominantly those adherent to nylon wool, of the Brucella-naive cattle.     

Sensitivity of Brucella spp to tetracycline and its analogues.

The sensitivity to eight tetracyclines of 100 strains of brucellae, comprising strains of Brucella abortus, Br. melitensis, and Br. suis, was determined. Demethylchlortetracycline was the most effecitve against all the groups of brucellae, whereas oxytetracycline and chlortetracycline were the least effective. The mean MIC value for demethylchlortetracycline, doxycycline, lymecycline, and tetracycline was less than or equal to 1 mug/ml. Strains of Br. abortus biotype 2 and Br. suis were the most sensitive strains examined.     

Endogenous gamma interferon mediates resistance to Brucella abortus infection.

Depletion of endogenous gamma interferon (IFN-gamma) with anti-IFN-gamma monoclonal antibody resulted in increased numbers of Brucella abortus in the spleen and liver of infected CBA mice. This increase was accompanied by a decrease in splenomegaly and a lower proportion of macrophages in the spleen. Furthermore, treatment of recipient mice with anti-IFN-gamma antibody blocked the adoptive transfer of resistance with immune T cells. Together, the results indicated that endogenous IFN-gamma plays an important role in mediating resistance to primary and secondary Brucella infection.     

Mycotic keratitis due to Engyodontium album: First case report from India

Engyodontium album is a rare and an unusual human pathogen. It is a common inhabitant of waste and moist material and frequently isolated from substrates such as paper, jute, linen and painted walls. This fungus grew within 3 days on SDA with chloramphenicol from corneal scrapping of a 70-year-old male farmer with a history of trauma by unknown vegetative matter. The fungus can be confused with Tritirachium sp and Beauveria sp.     

Porcine E-selectin: cloning and functional characterization.

E-selectin, a member of the selectin family, is believed to play an important role in mediating the initial adhesive events between leucocytes and the endothelium during inflammation. A monoclonal antibody against human E-selectin was found to cross-react with the porcine equivalent, a glycoprotein of 92,000 MW. Isolation of the cDNA for porcine E-selectin showed that it was 71% homologous with human E-selectin but had two less short consensus repeats. The porcine adhesion molecule could also support the adhesion of both porcine and human neutrophils. Expression of E-selectin on interleukin-1 alpha (IL-1 alpha)- or tumour necrosis factor-alpha (TNF-alpha)-activated porcine aortic endothelial cells in culture was prolonged, persisting for up to 48 hr. Binding studies using a chimeric molecule consisting of the lectin domain of porcine E-selectin and the epidermal growth factor (EGF) domain of human E-selectin fused to the human IgG constant region, further characterized porcine E-selectin as recognizing mainly granulocytic leucocytes and a subpopulation of lymphocytes.