The invasive pathogen Yersinia pestis disrupts host blood vasculature to spread and provoke hemorrhages

Yersinia pestis is a powerful pathogen with a rare invasive capacity. After a flea bite, the plague bacillus can reach the bloodstream in a matter of days giving way to invade the whole organism reaching all organs and provoking disseminated hemorrhages. However, the mechanisms used by this bacterium to cross and disrupt the endothelial vascular barrier remain poorly understood. In this study, an innovative model of in vivo infection was used to focus on the interaction between Y. pestis and its host vascular system. In the draining lymph nodes and in secondary organs, bacteria provoked the porosity and disruption of blood vessels. An in vitro model of endothelial barrier showed a role in this phenotype for the pYV/pCD1 plasmid that carries a Type Three Secretion System. This work supports that the pYV/pCD1 plasmid is responsible for the powerful tissue invasiveness capacity of the plague bacillus and the hemorrhagic features of plague.

The plague bacillus, Yersinia pestis, is a powerful pathogen with a rare invasive capacity and is among the few bacteria capable to provoke disseminated hemorrhages. However, the mechanisms used by this bacterium to cross and disrupt the endothelial vascular barrier remain poorly understood. Recent technical progress in microscopy, associated with the use of original fluorescent mutant in mice, allowed us to develop an innovative model of infection in vivo. This model permitted to look directly into the interaction between Y. pestis and its host vascular system, in 3D reconstructed tissues without physical alteration. We were able to observe the degradation of blood vessels in the draining lymph nodes and to visualize the spreading of the bacteria into secondary organs directly through the vascular barrier. Classical in vitro experiments validated the in vivo observation and demonstrated the role of some of the bacterial components in this phenotype. This work shows an unprecedented visualization of the pathogenesis of Y. pestis and decipher part of the powerful invasiveness capacity of the plague bacillus and the hemorrhagic features of plague.

Spontaneous rupture of pyogenic liver abscess with subcapsular hemorrhage mimicking ruptured hepatocellular carcinoma: A case report

RATIONALE

Spontaneous rupture of PLA (pyogenic liver abscess) is an extremely rare and life-threatening event. Ruptured PLA is very difficult to distinguish from malignant HCC (hepatocellular cancer) rupture or cholangiocarcinoma rupture on CT (computed tomography) scan.

PATIENT CONCERNS

We describe the case of a 71-year-old man with fever, right upper abdominal pain, nausea with intermittent vomiting, and general fatigue. He had no medical or surgical history.

DIAGNOSIS

CT scan showed a hypodense mass in right hepatic lobe and MRI (magnetic resonance imaging) revealed a heterogenous mass of ∼6 cm in segment VI of the liver and heterogenous fluid in the subcapsular region. We made a tentative diagnosis of HCC rupture with subcapsular hemorrhage based on these findings.

INTERVENTION

After improving the patient's condition by administering empirical therapy consisting of intravenous antibiotics and fluids, we performed surgical exploration. Gross examination of the abdomen showed that almost the entire right hepatic lobe was hemorrhagic and affected by peritonitis. Therefore, we performed right hepatectomy. The intraoperative frozen biopsy revealed suspicious PLA with marked necrosis, neutrophil infiltration, and hemorrhagic rupture, although no malignant tissue or fungus was observed. The postoperative secondary pathology report confirmed the diagnosis of PLA with hemorrhagic rupture.

OUTCOMES

The patient was discharged 13 days after the operation. Follow-up CT was performed 5 months after discharge and revealed no abnormal findings.

LESSONS

A high index of suspicion is key to preventing misdiagnosis of ruptured PLA and improving prognosis. Furthermore, even if rupture of the PLA is initially localized, delayed peritonitis may occur during medical treatment. Therefore, vigilant monitoring is essential.

Clinical Characteristics of Rapidly Progressive Fatal Hemorrhagic Pneumonia Caused by Stenotrophomonas maltophilia

Objective Hemorrhagic pneumonia due to Stenotrophomonas maltophilia (SM) in severely immunocompromised patients has a very poor prognosis. However, the risk factors for hemorrhagic pneumonia are not clear. Methods This study assessed the predictive factors of hemorrhagic pneumonia caused by SM. The medical records of patients admitted to Osaka City University Hospital with SM bacteremia between January 2008 and December 2017 were retrospectively reviewed. Patients All patients who had positive blood cultures for SM were included in this study. They were categorized into two groups: the SM bacteremia with hemorrhagic pneumonia group and the SM bacteremia without hemorrhagic pneumonia group. The clinical background characteristics and treatments were compared between these groups. Results The 35 patients with SM bacteremia included 4 with hemorrhagic pneumonia and 31 without hemorrhagic pneumonia. Hematologic malignancy (p=0.03) and thrombocytopenia (p=0.04) as well as the prior use of quinolone within 30 days (p=0.04) were more frequent in the SM bacteremia patients with hemorrhagic pneumonia than in those without hemorrhagic pneumonia. The mortality of the SM bacteremia patients with hemorrhagic pneumonia was higher than that of those without hemorrhagic pneumonia group (p=0.02). Conclusion Patients with SM bacteremia who have hematologic malignancy, thrombocytopenia, and a history of using quinolone within the past 30 days should be treated with deliberation.

Epidemiology and molecular characterization of the antimicrobial resistance of Pseudomonas aeruginosa in Chinese mink infected by hemorrhagic pneumonia

Hemorrhagic pneumonia in mink is a fatal disease caused by Pseudomonas aeruginosa. Very little is known about P. aeruginosa in relation to genotype and the mechanisms underlying antimicrobial resistance in mink. A total of 110 P. aeruginosa samples were collected from mink from Chinese mink farms between 2007 and 2015. Samples underwent molecular genotyping using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST), antimicrobial susceptibility and its mechanism were investigated at the molecular level. The PFGE identified 73 unique types and 15 clusters, while MLST identified 43 (7 new) sequence types (ST) and 12 sequence type clonal complexes (STCC). Sequence types and PFGE showed persistence of endemic clones in cities Wendeng (Shandong, China) and Dalian (Liaoning, China), even in different timelines. The MLST also revealed the gene correlation of the mink P. aeruginosa across different time and place. The ST1058 (n = 14), ST882 (n = 11), and ST2442 (n = 10) were the predominant types, among which ST1058 was the only one found both in Shandong province and Dalian (Liaoning, China). The MLST for P. aeruginosa infection in mink was highly associated with that in humans and other animals, implying possible transmission events. A small proportion of mink exhibited drug resistance to P. aeruginosa (9/69, 13%) with resistance predominantly to fluoroquinolone, aminoglycoside, and β-lactamase. Eight strains had mutations in the quinolone-resistance determining regions (QRDR). High proportions (65%; 72/110) of the fosA gene and 2 types of glpt deletion for fosmycin were detected. Furthermore, in the whole genome sequence of one multidrug resistant strain, we identified 27 genes that conferred resistance to 14 types of drugs.

Severe pulmonary haemorrhage syndrome in leptospirosis in a returning traveller

Clinical presentation of leptospirosis ranges from asymptomatic infection to fulminant, life-threatening disease. Pulmonary involvement in terms of severe pulmonary haemorrhage syndrome (SPHS) has recently become a more frequently reported facet of leptospirosis and correlates with high mortality rates. It has not yet been described in returning German travellers. We present a case of a healthy young man developing massive pulmonary haemorrhage and severe ARDS requiring mechanical ventilation and high-dose catecholamines after travelling to Indonesia. Leptospirosis was verified by blood PCR as well as serology and treated with high-dose, intravenous penicillin. Outcome was favourable, the patient recovered completely. Leptospirosis and SPHS should be taken into account as an emerging infectious disease in patients with fever and lung involvement.

Intraplaque hemorrhage, a potential consequence of periodontal bacteria gathering in human carotid atherothrombosis

Periodontal diseases are multifactorial inflammatory diseases, caused by a bacterial biofilm involving both innate and adaptative immunity, characterized by the destruction of tooth-supporting tissues. In the context of periodontitis, the spread of weak pathogenic bacteria into the bloodstream has been described. These bacteria will preferentially localize to existing clot within the circulation. Atherothrombosis of the carotid arteries is a local pathology and a common cause of cerebral infarction. Intraplaque hemorrhages render the lesion more prone to clinical complications such as stroke. The main objective of this study is to explore the biological relationship between carotid intraplaque hemorrhage and periodontal diseases. This study included consecutive patients with symptomatic or asymptomatic carotid stenosis, admitted for endarterectomy surgical procedure (n=41). In conditioned media of the carotid samples collected, markers of neutrophil activation (myeloperoxidase or MPO, DNA-MPO complexes) and hemoglobin were quantified. To investigate the presence of DNA from periodontal bacteria in atherosclerotic plaque, PCR analysis using specific primers was performed. Our preliminary results indicate an association between neutrophil activation and intraplaque hemorrhages, reflected by the release of MPO (p<0,01) and MPO-DNA complexes (p<0,05). Presence of DNA from periodontitis-associated bacteria was found in 32/41 (78%) atheromatous plaque samples. More specifically, DNA from Pg, Tf, Pi, Aa was found in 46%, 24%, 34% and 68% of the samples, respectively. Hemoglobin levels were higher in conditioned media in carotid samples where the bacteria were found, but this was not statistically significant. Our data confirm the relationship between intraplaque hemorrhage and neutrophil activation. In addition, the presence of periodontal bacteria DNA in carotid atheromatous plaque, may contribute to this activation. Further analysis is needed to fully explore the raw data and specimens.

Bacteria prevalence in a large Italian population sample: a clinical and microbiological study

The present study detects those bacterial species which are more strongly related to bleeding on probing, suppuration and smoking in periodontal-affected patients. Nine hundred and fifty-one patients with periodontal diseases were admitted to the Department of Periodontology and Implantology, Dental School of Bologna University where they underwent microbiological tests for six periodontal pathogens (Actinomyces actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Fusobacterium nucleatum and Tannerella forsythia). Cluster analysis explored the variables that mostly influence both the presence and absolute\relative bacterial load. Logistic regression and multivariate linear regression quantifies these relations. The probability of recovering bacteria belonging to the Red Complex is greater by 25-48% in presence of bleeding on probing. When probing depth is less than 3 mm the probability of presence of each bacterial species is inferior in comparison with depth >6 mm both for Red Complex (of 20-37%), the Orange complex (of 41-61%) and Actinomyces actinomycetemcomitans (46%). Total bacterial cell count increases with pocket depth above all for the Red Complex. As Treponema Denticola and Tannerella Forsytia presence is associated with bleeding on probing and Prevotella intermedia presence with suppuration and smoking. The examination of these three as indicators of periodontitis evolution is suggested.

Diffuse alveolar hemorrhage in a patient with acute poststreptococcal glomerulonephritis caused by impetigo

We herein report a case of pulmonary renal syndrome with nephritis in a 17-year-old boy with diffuse alveolar hemorrhage (DAH) associated with acute poststreptococcal glomerulonephritis (APSGN). The patient exhibited hemoptysis two weeks after developing impetigo, and DAH was diagnosed on bronchoscopy. Respiratory failure progressed, and high-dose methylprednisolone therapy was administered; the respiratory failure regressed immediately after the onset of therapy. Streptococcus pyogenes was detected in an impetigo culture, and, together with the results of the renal biopsy, a diagnosis of APSGN was made. This case demonstrates the effects of high-dose methylprednisolone therapy in improving respiratory failure.

Does cervical ureaplasma/mycoplasma colonization increase the lower uterine segment bleeding risk during cesarean section among patients with placenta previa? A cross-sectional study

OBJECTIVE

The underlying inflammation of endometrium may impede normal implantation of placenta during pregnancy. Our objective is to show cervical colonization of ureaplasma and/or mycoplasma as a marker of endometritis in pregnancies complicated with placenta previa that can be a risk factor for placenta accreta and peripartum hemorrhage.

PATIENTS AND METHODS

Cervical cultures for ureaplasma urealyticum and mycoplasma genitalium have been taken from the endocervical region of the cervix of the patients. Subsequent uterine lower segment bleeding suggesting placenta implantation defects have been evaluated during cesarean section.

RESULTS

Of 25 patients: ten (40%) had negative cervical cultures for cervical mycoplasma and/or ureaplasma, 9 (36%) were found to be culture positive for cervical ureaplasma, 1 (4%) was found to be culture positive for cervical mycoplasma. Half of the 10 patients with positive cervical cultures for ureaplasma or mycoplasma and 6 of (40%) 15 patients with negative results had experienced lower uterine segment bleeding during cesarean section.

CONCLUSIONS

Bacterial colonization of cervix in particular with ureaplasma and/or mycoplasma is found to be strongly associated with placenta previa. Before a planned pregnancy, treatment of this infection with appropriate antibiotics is necessary to prevent underlying uterine endometritis that increases the risk for abnormal implantation of placenta.

[Comparative evaluation of efficacy of histological and cytological methods of H. pylori primary diagnosis in pyloroduodenal ulcer complicated by hemorrhage]

In 48 patients, suffering gastroduodenal ulcer disease, complicated by hemorrhage, cytological and histological investigations were conducted to reveal helicobacter infection. There was established, that sensitivity, specificity and accuracy of smears--the gastric mucosa imprints--cytological investigation exceeds such of histological investigation of biopsies. In more than 80% patients, in whom pyloroduodenal ulcer, complicated by hemorrhage, was diagnosed, Helicobacter pylori (H. pylori) was revealed in gastric mucosa.

[Acute hemorrhagic syndrome by lupus anticoagulant]

Antiphospholipid antibodies are correlated to antiphospholipid syndrome, that is characterized by one or more thrombotic episodes and obstetric complications. Some recent studies have evidenced as antiphospholipid antibodies can be correlated to an transitory hemorrhagic syndrome with prolonged aPTT. This syndrome compares 7-10 days after a bacterial or viral infection and it is characterized by a spontaneous regression into a period of three months. The aim of this paper is to evidence the pathogenesis and the clinical aspects of this syndrome.

Tumor invasion of Salmonella enterica serovar Typhimurium is accompanied by strong hemorrhage promoted by TNF-alpha

Background

Several facultative anaerobic bacteria with potential therapeutic abilities are known to preferentially colonize solid tumors after systemic administration. How they efficiently find and invade the tumors is still unclear. However, this is an important issue to be clarified when bacteria should be tailored for application in cancer therapy.

Methodology/Principal Findings

We describe the initial events of colonization of an ectopic transplantable tumor by Salmonella enterica serovar Typhimurium. Initially, after intravenous administration, bacteria were found in blood, spleen, and liver. Low numbers were also detected in tumors associated with blood vessels as could be observed by immunohistochemistry. A rapid increase of TNF-α in blood was observed at that time, in addition to other pro-inflammatory cytokines. This induced a tremendous influx of blood into the tumors by vascular disruption that could be visualized in H&E stainings and quantified by hemoglobin measurements of tumor homogenate. Most likely, together with the blood, bacteria were flushed into the tumor. In addition, blood influx was followed by necrosis formation, bacterial growth, and infiltration of neutrophilic granulocytes. Depletion of TNF-α retarded blood influx and delayed bacterial tumor-colonization.

Conclusion

Our findings emphasize similarities between Gram-negative tumor-colonizing bacteria and tumor vascular disrupting agents and show the involvement of TNF-α in the initial phase of tumor-colonization by bacteria.

Lethal Pulmonary Hemorrhage Caused by a FulminantStenotrophomonas maltophiliaRespiratory Infection in an Acute Myeloid Leukemia Patient

Stenotrophomonas maltophilia (Sm) pneumonia in immunocompromized hosts is an increasingly common nosocomial infection. Even though resistant to multiple antimicrobials, this gram-negative bacteria usually does not present with a fulminant course leading to a fatal hemorrhagic respiratory infection in neutropenic patients. We report here the case of a 63-year-old woman treated by intensive chemotherapy for acute myeloid leukemia (AML) who presented while severely neutropenic and thrombocytopenic a Sm pulmonary infection with hemoptysis leading to death in 48 h. The bronchoalveolar lavage (BAL) performed shortly before death was highly hemorrhagic and contained a striking amount of extra- and intra-cellular pathogens. Blood and BAL cultures grew S. maltophilia. Post-mortem examination revealed bilateral extensive intra-alveolar hemorrhage (IAH) associated with a great amount of microorganisms and severe bone marrow aplasia was observed without evidence of leukemia residual disease. Sm pneumonia usually does not evolve into such a devastating clinical picture although infections due to the bacteria are known to be associated with high morbidity and mortality. So far, the present observation is the fourth similar case reported in the literature. Even though an early diagnosis and an adequate antibiotic prescription may improve Sm infection prognosis, S. maltophilia proves difficult to eradicate due to a high resistance rate in part intrinsic but also in part acquired.

Fatal Staphylococcus aureus haemorrhagic pneumonia producing Panton-Valentine leucocidin

We present 2 cases of community acquired S. aureus pneumonia carrying Panton Valentine leucocidin (PVL). These cases illustrate this clinical entity characterized by a younger and healthier population than usual staphylococcal pneumonias and complicated by a 75% mortality rate. We also discuss the diagnosis and therapeutic difficulties.

[Cross-sectional study of leptospirosis cases admitted to the Iaşi Clinic of Infectious Diseases over a 5-years period]

Leptospirosis is a zooantroponosis manifested as an infection with a severe evolution, with liver and renal failure and haemoragic manifestation. The aim of the study was to present the epidemiologic, clinic and therapeutical aspects of 100 cases of leptospirosis admitted in the clinic of Infectious Diseases of Iaşi, during 5 years (2002-2006).

MATERIAL AND METHOD

The diagnostic was based on the clinical-biologic study and risk factors with febrile syndrome, mialgic syndrome, headache, meningial, liver and renal failure and hematological syndromes, with the serologic evidence of serotypes of leptospirosis.

RESULTS

All the patients were serologic confirmed with leptospirosis. Leptospirosis is an emergent disease with the possibility of severe evolution in some forms, with lever and renal failure.

Corynebacterial necrohemorrhagic cystitis in two female macaques

We describe severe necrohemorrhagic cystitis in a female rhesus macaque and a female cynomolgus macaque due to colonization of the urinary bladder by Corynebacterium sp. Clinically, both macaques presented with perineal bleeding and depression and, despite extensive and prolonged treatment, succumbed to the disease. At necropsy, the contents of the urinary bladders in both cases were hemorrhagic to greenish black, and the bladder mucosa was necrotic. The major microscopic finding in each case was transmural necrohemorrhagic cystitis, with vasculitis, fibrin thrombi, and myriad gram-positive coryneform bacilli. Corynebacterium renale, Streptococcus acidominimus, and S. oralis were cultured from the urinary bladder of the rhesus macaque, and a nondiphtheritic Corynebacterium was cultured from the urinary bladder of the cynomolgus macaque. Neither animal had any other noteworthy pathologic lesions unrelated to bacterial cystitis. Corynebacterial necrohemorrhagic cystitis therefore was determined to be the cause of death in both animals. To our knowledge, this is the fi rst report of corynebacterial cystitis in nonhuman primates.

Syndrome de Waterhouse-Friderichsen au cours d'une péritonite à Morganella morganii et Enterococcus faecium

About fifty to sixty percent of patients with septic shock acquire acute adrenal insufficiency. This insufficiency is most often relative, but can sometimes be absolute. Bilateral adrenal haemorrhage is a rare aetiology of absolute acute adrenal insufficiency. It is classically described in patients with severe meningococcemia (purpura fulminans), who commonly present many of the risk factors associated with bilateral adrenal haemorrhage (shock, coagulation disorders, sepsis). We report a case of bilateral adrenal haemorrhage during a peritonitis complicated by a septic shock, with no coagulation disorder. This observation shows up that this bilateral adrenal haemorrhage can complicate severe sepsis of various origins, and not only severe meningococcemia. It can be suspected in face of a septic shock with an unfavourable evolution despite adequate treatment.

Acute pulmonary hemorrhage during isoflurane anesthesia in two cats exposed to toxic black mold (Stachybotrys chartarum)

CASE DESCRIPTION

Acute pulmonary hemorrhage developed during isoflurane anesthesia in 2 Himalayan cats undergoing routine dental cleaning and prophylaxis.

CLINICAL FINDINGS

The cats were siblings and lived together. In both cats, results of pre-operative physical examinations and laboratory testing were unremarkable. Blood pressure and oxygen saturation were within reference ranges throughout the dental procedure. Approximately 15 to 20 minutes after administration of isoflurane was begun, frothy blood was noticed within the endotracheal tube. Blood was suctioned from the endotracheal tube, and the cats were allowed to recover from anesthesia.

TREATMENT AND OUTCOME

1 cat initially responded to supportive care but developed a second episode of spontaneous pulmonary hemorrhage approximately 30 hours later and died. The other cat responded to supportive care and was discharged after 4 days, but its condition deteriorated, and the cat died 10 days later. Subsequently, it was discovered that the home was severely contaminated with mold as a result of storm damage that had occurred approximately 7 months previously. Retrospective analysis of banked serum from the cats revealed satratoxin G, a biomarker for Stachybotrys chartarum, commonly referred to as "toxic black mold."

CLINICAL RELEVANCE

Findings highlight the potential risk of acute pulmonary hemorrhage in animals living in an environment contaminated with mold following flood damage.

Specificity of immunomodulator secretion in urinary samples in response to infection by alpha-hemolysin and CNF1 bearing uropathogenic Escherichia coli

Escherichia coli are the most common etiological agents of urinary tract infections (UTIs). Uropathogenic E. coli (UPECs) produce specific toxins including the cytotoxic necrotizing factor-1 (CNF1) and the alpha-hemolysin (alpha-Hly). CNF1 triggers, through Rho protein activation, a specific gene response of host cells, which results in the production for instance of interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1) and the macrophage inflammatory protein-3alpha (MIP-3alpha). The alpha hemolysin alpha-Hly also triggers the production of inflammatory mediators. Cnf1 is always associated with alpha-hly in a pathogenicity island conserved among UPECs. Using two complementary approaches we have investigated whether alpha-hly and cnf1 bearing UPECs are associated with a specific type of UTI both in term of pathology and host response. Here we report that UPECs bearing alpha-hly/cnf1 have a prevalence of 50% in UPECs isolated from hemorrhagic UTIs, as compared to 30% in the overall UPEC population. In addition, we observed that MCP-1, and IL-8 to a lower extent, is produced in urine at higher concentrations in UTIs caused by UPECs carrying alpha-hly/cnf1.

Sex differences in clinical leptospirosis in Germany: 1997-2005

BACKGROUND

Although the majority of patients with reported leptospirosis are male, several seroepidemiologic studies demonstrated that leptospirosis seroprevalences are at least identical between both sexes. To study the effect of sex on the severity--and possibly, recognition--of leptospirosis, we conducted a sex-specific analysis of the clinical manifestations of the disease among patients with reported leptospirosis in Germany during 1997-2005.

METHODS

Data on demographic characteristics, symptoms, place of infection and place of residence when infection occurred, possible exposure risks, infecting serovars, and mortality were evaluated for patients with laboratory-confirmed leptospirosis reported in Germany during 1997-2005. Mantel-Haenszel odds ratios (OR(MH)), adjusted for age, were used to determine the association between sex and the frequency of reported symptoms.

RESULTS

Among 338 patients with leptospirosis (263 male patients and 75 female patients) reported in Germany during 1997-2005, male patients were more likely than female patients to be hospitalized (OR, 2.6; P<.01) and to exhibit symptoms of severe leptospirosis with jaundice (OR(MH), 3.7; P<.01), renal impairment (OR(MH), 3.4; P<.01), and hemorrhage (OR(MH), 7.8; P<.05). These sex-related differences were not associated with differences in exposure risks, presumptive infecting serogroups, or health-seeking behavior.

CONCLUSIONS

Our results indicate that male sex is associated with a higher severity of clinical leptospirosis. Reports on male predominance in leptospirosis may thus reflect sex-related variability in the incidence of severe disease, rather than different infection rates. In clinical practice, sex differences in the manifestation of leptospirosis may cause systematic underinvestigation and undertreatment of the disease in female patients.

Pathology of fatal traumatic and nontraumatic clostridial gas gangrene: a histopathological, immunohistochemical, and ultrastructural study of six autopsy cases

We prospectively investigated six fatal cases of clostridial gas gangrene using autopsy, histology, immunohistochemistry, microbiology, and scanning electron microscopy. The causative pathogen was Clostridium perfringens in four cases, C. sordellii in one case, and a mixed infection with both C. perfringens and C. sordellii in one case. According to the previous medical history and autopsy findings, clostridial infection was related to trauma in three cases. Characterized by extensive tissue necrosis and total absence of an accompanying leukocyte infiltration and tissue inflammatory response, the histopathological picture of clostridial gas gangrene is distinctly different from other bacterial infections. In medicolegal casework, the proof of the source of infection and the portal of entry of the responsible pathogen is not always an easy task, especially in the absence of trauma.

Severe pulmonary haemorrhage accompanying hepatorenal failure in fulminant leptospirosis

Leptospirosis is a re-emerging spirochetal zoonosis with a worldwide distribution affecting both animals and humans. The clinical syndromes may vary from a subclinical infection to a severe illness. Although it may potentially have a fulminant and fatal course, leptospirosis usually remains as an underdiagnosed cause of multiorgan failure. In this study, we report a patient with leptospirosis who presented with a fulminant course of diffuse alveolar haemorrhage and hepatorenal failure. His clinical condition deteriorated, despite appropriate antibiotic therapy and haemodialysis. However, he showed prompt clinical improvement when corticosteroids and plasma exchange were instituted in addition to the original therapy. We conclude that leptospirosis should be considered in any case presenting with pulmonary haemorrhage and hepatorenal failure. Plasma exchange and corticosteroids may be a choice of treatment in selected patients unresponsive to conventional therapy. Potential benefits of plasma exchange and corticosteroids may be based on a toxin- and/or cytokine-mediated pathogenesis of the disease.

Pathophysiological manifestations in mice exposed to anthrax lethal toxin

Pathophysiological changes associated with anthrax lethal toxin included loss of plasma proteins, decreased platelet count, slower clotting times, fibrin deposits in tissue sections, and gross and histopathological evidence of hemorrhage. These findings suggest that blood vessel leakage and hemorrhage lead to disseminating intravascular coagulation and/or circulatory shock as an underlying pathophysiological mechanism.

Fever, pulmonary haemorrhage, and acute renal failure in a young girl

Leptospirosis is rarely reported in children. It is easily treated with antibiotics but can be fatal if treatment is delayed. A 12-year-old girl was diagnosed with Weil syndrome, a severe form of leptospirosis, 10 days after returning from Mainland China. She presented with fever, hypotension, jaundice, and acute renal failure. She had used well water for bathing and swum in freshwater.

Isolation of necrotoxigenic Escherichia coli from a dog with hemorrhagic pneumonia

A 7-month-old sexually intact male Cocker Spaniel was admitted to the North Carolina State University Veterinary Teaching Hospital for evaluation of lethargy, panting, and excessive salivation that had become progressively severe during a 5-hour period. Despite intensive medical care, the dog died within the first 24 hours of hospitalization, and death was attributed to acute, severe, necrotizing pneumonia. Lung tissue collected at necropsy by use of swabs was cultured and yielded an isolate of Escherichia coli; because of the rapid progression of illness in an otherwise healthy dog, the isolate underwent virulence typing and was determined to be a necrotoxigenic E. coli. Necrotoxigenic E. coli produce a toxin called cytotoxic necrotizing factor and are known to be involved in extraintestinal infections, including urinary tract infection, in humans and animals. Virulence typing of E. coli isolates from dogs with peracute pneumonia is recommended to further characterize the epidemiologic characteristics and public health importance of necrotoxigenic E. coli.

Helicobacter pylori infection and platelet counts during pregnancy

OBJECTIVE

To investigate whether there is any correlation between Helicobacter pylori infection and platelet counts during pregnancy.

METHODS

One hundred and twenty pregnant women without any complications were evaluated. Platelet counts were determined during pregnancy and postpartum. H. pylori infection was assessed by the detection of serum antibodies at the 3rd day postpartum. Statistically significant differences of platelet count between H. pylori-positive and -negative patients were determined.

RESULTS

H. pylori infection was found in 29 of 120 (24.2%). Platelet counts in the 3rd trimester were 22.7+/-4.7 x 10(3)/microl in H. pylori-positive group and 22.8+/-5.6 x 10(3)/microl in negative group (p=0.98). Platelet count in the 3rd trimester in positive and negative patients were 93+/-17% and 94+/-20%, respectively, of that of the 1st trimester (p=0.92). The incidence of hyperemesis gravidarum in both groups was not significant (p=0.28).

CONCLUSION

A correlation between H. pylori infection and thrombocytopenia during pregnancy was not found in this study.

Leptospirosis: a case report of a patient with pulmonary haemorrhage successfully managed with extra corporeal membrane oxygenation

Leptospirosis is a zoonosis of worldwide significance. Pulmonary involvement is common but often mild and of little clinical significance. However, over the last two decades an increasing number of cases have been reported with pulmonary haemorrhage as a prominent feature [Carvalho CR, Bethlem EP. Pulmonary complications of leptospirosis. Clin Chest Med, 2002;23(2):469-78]. These cases are particularly challenging to treat as they often have resistant hypoxaemia despite maximal invasive mechanical ventilation. Consequently, there is a high mortality rate. Here, we present a case of severe leptospirosis complicated by massive pulmonary haemorrhage which was successfully managed by extra corporeal membrane oxygenation (ECMO).

The ultimate development of mitral valve endocarditis: atrioventricular separation, atrioventricular groove abscess and hemorrhagic pericarditis

A 52-year-old non-insulin-dependent diabetic man presented with cerebral emboli and mitral valve endocarditis with posterior leaflet vegetations and perforation. Surgical intervention demonstrated hemorrhagic pericarditis and an atrioventricular groove abscess. Extensive debridement of the pericardium, valve and abscess cavities, reconstruction of the mitral annulus with a patch of fresh autologous pericardium, and mitral valve replacement with a pericardial bioprosthesis was performed. The chest was left open. Postoperatively, the patient required dialysis and prolonged mechanical ventilation, but recovered well without recurrent endocarditis and was discharged home after 40 days.

Fatal hemorrhagic pneumonia concomitant with Chlamydia pneumoniae and parainfluenza virus 4 infection

CONTEXT

Cases of fatal hemorrhagic pneumonia need to be investigated for highly contagious viral causes. While not all hemorrhagic pneumonias are caused by very contagious agents, the etiology must be correctly determined in order to administer appropriate patient care.

OBJECTIVE

To determine whether chlamydia, paramyxovirus, or mycoplasma was the causative agent in a case of fatal hemorrhagic pneumonia, and to evaluate the possibility that this was the first case of hantavirus pulmonary syndrome in Illinois.

DESIGN

Nonroutine virological and molecular analyses were performed on lung tissue taken during an unrestricted autopsy of a patient who died in 2002. SETTING AND PATIENT: An elderly, male, Chicago-area resident with a 3-week history of nonspecific, mild upper respiratory tract infection was admitted for hospital treatment of the respiratory infection and viral myositis without cardiac involvement. The patient became febrile, hypoxic, developed hemorrhagic pneumonia, and died. Because he had proven exposure to mice and had developed hemorrhagic pneumonia, hantavirus pulmonary syndrome was suspected as the cause of death. Mice known to carry hantaviruses live in Illinois, including the Chicago area.

INTERVENTIONS

Gatifloxacin and heparin anticoagulation were initiated because community-acquired pneumonia and pulmonary embolism were considered likely etiologies for an acute exacerbation of hypoxemia.

RESULTS

Two respiratory pathogens were isolated and identified: Chlamydia pneumoniae and human parainfluenza virus 4a.

CONCLUSIONS

A mixed (polymicrobial) infection contributed to the patient's death. Hemorrhage was likely a result of anticoagulation therapy superimposed on lung tissues damaged by pneumonia. The uncommon nature of this case and the pathogens involved underscore the challenges in infection control and clinical evaluation that hospitals will face when confronted with possibly new and potentially deadly communicable diseases.

Quantitative polymerase chain reaction analysis of fungi in dust from homes of infants who developed idiopathic pulmonary hemorrhaging

Fungal concentrations were measured in the dust of 6 homes in Cleveland, Ohio, where an infant developed pulmonary hemorrhage (pulmonary hemorrhage homes [PHH]) and 26 reference homes (RH) with no known fungal contamination. Quantitative polymerase chain reaction assays for 82 species (or assay groups) were used to identify and quantify fungal concentrations. The ratios of the geometric means of PHH to RH were >1 for 26 species (group I). However, the same ratios were <1 for 10 species (group II). Probit analysis of the sum of the logs of the concentrations of these 2 groups resulted in a 95% probability range for separating PHH from RH homes. The same 82 fungal species were also tested for hemolysin production on sheep's blood agar (incubated at 37 degree C). Hemolysins were more commonly produced by group I species (42%) compared with group II species (10%).

A family outbreak of haemolytic uraemic syndrome and haemorrhagic colitis caused by verocytotoxigenic Escherichia coli O157 from unpasteurised cow's milk in Slovakia

This report describes a family outbreak of verocytotoxigenic Escherichia coli O157 (VTEC) infection, involving nine persons from one extended family, which occurred in eastern Slovakia. Three children suffered from haemolytic uraemic syndrome, two children had bloody diarrhoea, and four adults were asymptomatic carriers. Fourteen sorbitol-non-fermenting E. coli O157 isolates harbouring the vtx2, eae and ehxA genes were obtained. Verocytotoxin 2 activity was demonstrated in all 14 isolates. After epidemiological surveillance, the source of infection was identified as unpasteurised cow's milk.

Waterhouse-Friderichsen syndrome as a result of non-meningococcal infection

Waterhouse-Friderichsen syndrome--massive adrenal haemorrhage in the setting of overwhelming clinical sepsis--is usually taken at necropsy to indicate meningococcal infection, and may be the only evidence of this pathogen. This report describes three fatal cases of the syndrome in which the causative organism proved to be a streptococcus. The organisms were detected during routine coroners' autopsies with histology and microbiological investigations. In two cases, the syndrome followed Streptococcus pneumoniae infection and in a third beta haemolytic streptococcus group A. Thus, adrenal haemorrhage alone cannot be taken to indicate meningococcal disease and other pathogens, particularly streptococcus, must be considered.

Attributes of Stachybotrys chartarum and its association with human disease☆

Mold contamination and toxicities are not limited to crops and animals; they are also a concern in human health. Molds occur in outdoor and indoor environments, and water-damaged buildings harbor and provide substrate for several mold species. Of these, Stachybotrys chartarum poses a particular threat to occupants. Patients with building-related symptoms and infant idiopathic pulmonary hemorrhage often have histories of living in moldy, water-damaged buildings. Although a causal connection is far from being unequivocally proven, S. chartarum has been associated with such clinical conditions. These illnesses could be attributed in part to mycotoxins released by S. chartarum. Recently, a hemolysin released by this mold was found to be hemolytic in vitro and in vivo. In addition, allergenic proteins have been characterized from S. chartarum. The exact mechanism of S. chartarum pathogenesis has not yet been defined. Moreover, a causality-effect relation is not yet established. This review summarizes available information on the pathogenic attributes of S. chartarum and calls for well-controlled objective studies.

Fatal pulmonary hemorrhage associated with micrococcal infection in two children with acute lymphoblastic leukemia

Pulmonary hemorrhage is a rare cause of death in patients with acute leukemia. Within a 2-month period the authors observed two fatal pediatric cases, which were associated with opportunistic organisms of the genus Micrococcus. Both patients were receiving consolidation treatment for acute lymphoblastic leukemia. The authors discuss the causes of pulmonary hemorrhage in patients with leukemia and review the relevant literature. Micrococci have previously been considered as non-pathogenic, but there is considerable evidence for morbidity and mortality occurring, particularly in immunocompromised patients. The authors propose that micrococcal infection may have been a major predisposing factor for pulmonary hemorrhage in these thrombocytopenic patients.

[Features of clinical course of enteric fever associated with polyresistant strains of Sp.typhi 61-0 ]

Particular features have been studied of the clinical course of present-day abdominal typhoid caused by Sp. typhi 61-0 polyresistant strains. The clinical analysis performed has shown that Sp. typhi 61-0 polyresistant strain-associated enteric fever runs a moderately severe and severe course. There is an increased frequency of complications such as intestinal hemorrhage, perforated intestine, pneumonia, in the above patients. In the time-related course of the disease, Widal's reaction is not considered to be expedient for use in the diagnosis of Sp. typhi 61-0 strain-associated abdominal fever.

[Haemorrhagic cellulitis: three cases]

BACKGROUND

Haemorrhagic erysipelas (cellulitis) is a recently described clinical condition. We report 3 new cases of this rare bacterial dermatosis requiring both antibiotics and systemic corticosteroids for complete resolution.

CASE REPORTS

Case 1 was a 75 year-old male patient, with a past history of hypertension and diabetes mellitus. Case 2 was a 69 year-old female patient with a past history of hepatic cirrhosis. Case 3 was a 56 year-old female patient without medical past history, except for obesity. All patients presented with a haemorrhagic and bullous erysipelas of the leg without clinical improvement under parenteral antibiotics. In all cases, adjuvant systemic corticosteroids (prednisone: 0.5 mg/kg/d) for 5-8 days in addition to antibiotics provided dramatic and complete resolution of skin lesions and disappearance of pain and fever.

DISCUSSION

Haemorrhagic cellulitis may be misdiagnosed as necrotizing fasciitis because of ecchymotic areas with frequent bullae resulting in haemorrhagic crusts and partial inefficacy of antibiotics given alone. Adjuvant anticoagulant therapy or coagulation abnormalities may have facilitated the clinical condition in 2 of our 3 cases. The efficacy of adjuvant systemic corticosteroids during 5-8 days, in addition to antibiotics is the hallmark of this syndrome.

Forage feeding to reduce preharvest Escherichia coli populations in cattle, a review

Although Escherichia coli are commensal organisms that reside within the host gut, some pathogenic strains of E. coli can cause hemorrhagic colitis in humans. The most notable enterohemorrhagic E. coli (EHEC) strain is O157:H7. Cattle are asymptomatic natural reservoirs of E. coli O157:H7, and it has been reported that as many as 30% of all cattle are carriers of this pathogen, and in some circumstances this can be as high as 80%. Feedlot and high-producing dairy cattle are fed large grain rations in order to increase feed efficiency. When cattle are fed large grain rations, some starch escapes ruminal microbial degradation and passes to the hind-gut where it is fermented. EHEC are capable of fermenting sugars released from starch breakdown in the colon, and populations of E. coli have been shown to be higher in grain fed cattle, and this has been correlated with E. coli O157:H7 shedding in barley fed cattle. When cattle were abruptly switched from a high grain (corn) diet to a forage diet, generic E. coli populations declined 1000-fold within 5 d, and the ability of the fecal generic E. coli population to survive an acid shock similar to the human gastric stomach decreased. Other researchers have shown that a switch from grain to hay caused a smaller decrease in E. coli populations, but did not observe the same effect on gastric shock survivability. In a study that used cattle naturally infected with E. coli O157:H7, fewer cattle shed E. coli O157:H7 when switched from a feedlot ration to a forage-based diet compared with cattle continuously fed a feedlot ration. Results indicate that switching cattle from grain to forage could potentially reduce EHEC populations in cattle prior to slaughter; however the economic impact of this needs to be examined.