Persistently elevated IgA antibodies to Mycoplasma pneumoniae in patients with internal carotid artery stenosis

Background: It has been suggested that Mycoplasma pneumoniae may play a role in the development of atherosclerosis, but to date this association is still a matter of debate due to conflicting findings.

Methods: We have investigated the levels of specific IgA antibodies to M. pneumoniae in 91 patients with internal carotid artery (ICA) stenosis using a commercial kit (SeroMP™ IgA; Savyon Diagnostics, Israel; cut-off value: 20 binding units; BU). All patients underwent surgery for ICA stenosis. From each patient, the first serum sample (S1) was taken before surgery, and the second after an interval of 6 month (S2).

Results: The S1 seroprevalence was 18.7% (17/91). Thirteen of the 17 patients with positive S1 levels also remained positive after six month, whereby no decrease of IgA level was seen (median S1 level: 34 BU, range: 22–65 BU; median S2 level: 37 BU, range: 22–58 BU). Specifically, six of the patients showed an increased level after 6 months, and six a decrease, with the level remaining constant in one patient. In contrast, only 3 of the 74 S1 negative patients became positive for anti-M. pneumoniae IgA between the taking of the first and the second serum specimen (p<0.01). None of the assessed demographic factors or risk factors for atherosclerosis was associated with IgA seropositivity, neither were the degree CAVK or the degree of stenosis.

Conclusion: These findings cannot be explained throughout by the general seroprevalence, or by past respiratory tract infections with the pathogen, and therefore may suggest a role for M. pneumoniae in the development of atherosclerosis, since a chronic infection must be assumed.

Changing pattern of candidaemia 2001–2006 and use of antifungal therapy at the University Hospital of Vienna, Austria

A retrospective survey of candidaemia between 2001 and 2006 was performed at the University Hospital of Vienna, a 2200-bed centre with large organ transplantation and haematology-oncology units. The incidence rate of Candida spp. in blood cultures increased from 0.27 cases/1000 admissions in 2001 to 0.77 cases/1000 admissions in 2006 (p <0.005). The incidence of candidaemia caused by Candida albicans and by non-albicans Candida spp. both increased during this period; although there was a trend towards an increased incidence (37%) of non-albicans Candida spp., particularly Candida glabrata, in surgical wards, C. albicans remained the predominant pathogen (63%). In the haematology-oncology unit, C. albicans remained the leading pathogen (23/29 isolates, 79%), followed by Candida tropicalis and C. glabrata (2/29, 7% each), Candida sake and Candida lusitaniae (1/29, 3% each). The overall survival rate was 43.8%, ranging from 32.8% in 2004 to 63.6% in 2002. In total, 108 (33.2%) patients died within 4 weeks of the first isolation of Candida spp. from blood; 58 (54%) of these patients died within the first 7 days, and a further 34 patients died within the next 3 months. Fluconazole was used extensively (24 701.5 defined daily doses), followed by amphotericin B (8981.4 defined daily doses), during 2005. The consumption of antifungal agents increased continuously (p <0.05) because of increased use of voriconazole and caspofungin. Although the numbers of susceptible patients remained unchanged, the net increase in the number of cases of candidaemia warrants a re-evaluation of the risk-factors and the use of improved diagnostic procedures for invasive fungal infections.

Extended double disc synergy testing reveals a low prevalence of extended-spectrum β-lactamases in Enterobacter spp. in Vienna, Austria

OBJECTIVES

The aims of this study were to determine the prevalence of extended-spectrum beta-lactamases (ESBLs) in AmpC-carrying Enterobacter spp. in a tertiary care university hospital in Vienna, Austria, and to implement a cost-effective strategy to detect ESBLs in this particular genus on a routine basis.

METHODS

Clinical Enterobacter isolates (n=208) were investigated by means of (i) an inhibitor-potentiated diffusion test using cefpodoxime, (ii) an expanded double disc diffusion synergy test (discs of cefotaxime, ceftazidime, cefpodoxime and cefepime placed around amoxicillin/clavulanic acid), (iii) the Etest ESBL screening method and (iv) the cefoxitin-cefotaxime antagonist test. Cefepime MICs were determined by separate Etests.

RESULTS

Of 208 isolates, 76 (37%), 18 (9%) and 92 (44%) were derepressed, partially derepressed and inducible AmpC producers, respectively. Eight (4%) ESBL-producing Enterobacter strains could be detected, all of which would have been detected using disc-based tests. Six out of eight strains were genetically not related, as assessed by random amplification of polymorphic DNA. Typing results were confirmed by means of enterobacterial repetitive intergenic consensus PCR. The MIC(90) of cefepime was not different in ESBL carriers (range 2-4 mg/L), and was especially low in inducible AmpC producers (0.125 mg/L). More than half of all Enterobacter isolates (n=110; 53%) were partly derepressed or fully inducible AmpC producers. In the absence of cefoxitin, they appeared susceptible or intermediately susceptible to cefazolin (n=8; 9%), cefuroxime (n=75; 81.5%), ceftazidime (n=91; 99%), cefotaxime (n=92; 100%), cefpodoxime (n=75; 81.5%) and cefepime (n=91; 99%).

CONCLUSIONS

Susceptibility to third-generation cephalosporins would have been falsely assumed in more than half of all Enterobacter isolates, but ESBL in Enterobacter is currently rare in our institution. Integration of multiple double disc tests into the routine antibiogram seems a reliable approach to screen for emerging resistance mechanisms. Etests did not provide additional information in this study.

Somatostatin receptor scintigraphy in patients with cat-scratch disease

Aim: Somatostatin receptor scintigraphy images various neoplastic, granulomatous, and auto-immun diseases. Cat-scratch disease in an infectious granulomatous disease usually affecting the lymphnodes. It is not known whether cat-scratch disease provides positive somatostatin receptor scintigrams. Patients, methods: Twelve patients with lymphadenitis and suspected cat-scratch disease were investigated by immunofluorescence antibody testing and somatostatin receptor scintigraphy. Suppurated lymphnodes were extracted or drained and Bartonella henselae specific PCR was then performed. Results: Eleven of 12 patients showed IgG antibodies against B. henselea. SRS showed positive scintigraphic results in 6 of 11 patients with CSD. B. henselae DNA was detected in tissue of lymphnodes from 4 of 5 patients with lymphnode extraction or lymphnode drainage. SRS demonstrated positive scintigrams in all patients with a positive PCR. In one patient with suspected CSD SRS was negative as well as antibody testing. Conclusion: Somatostatin receptor scintigraphy correlated with positive Bartonella henselae specific PCR tests and positive Bartonella henselae specific antibody tests in patients with CSD.

Somatostatin receptor scintigraphy in patients with cat-scratch disease

AIM

Somatostatin receptor scintigraphy images various neoplastic, granulomatous, and auto-immune diseases. Cat-scratch disease in an infectious granulomatous disease usually affecting the lymphnodes. It is not known whether cat-scratch disease provides positive somatostatin receptor scintigrams.

PATIENTS, METHODS

Twelve patients with lymphadenitis and suspected cat-scratch disease were investigated by immunofluorescence antibody testing and somatostatin receptor scintigraphy. Suppurated lymphnodes were extracted or drained and Bartonella henselae specific PCR was then performed.

RESULTS

Eleven of 12 patients showed IgG antibodies against B. henselae. SRS showed positive scintigraphic results in 6 of 11 patients with CSD. B. henselae DNA was detected in tissue of lymphnodes from 4 of 5 patients with lymphnode extraction or lymphnode drainage. SRS demonstrated positive scintigrams in all patients with a positive PCR. In one patient with suspected CSD SRS was negative as well as antibody testing.

CONCLUSION

Somatostatin receptor scintigraphy correlated with positive Bartonella henselae specific PCR tests and positive Bartonella henselae specific antibody tests in patients with CSD.

Closed suctioning system reduces cross-contamination between bronchial system and gastric juices

In this prospective, randomized study, we evaluated whether a closed suctioning (CS) system (TrachCare) influences crossover contamination between bronchial system and gastric juices when compared with an open suctioning system (OS). The secondary aims were an analysis of the frequency of ventilator-associated pneumonia (VAP) and an analysis of alteration in gas exchange. Antibiograms were performed from tracheal secretions and gastric juice aspirates on Days 1 and 3 of intubation in 24 patients in a medical intensive care unit. Five cross-contaminations were observed in the OS group on Day 3 versus Day 1; the 5 strains shared common genotypes as determined by random amplification of polymorphic DNA. No cross-contaminations were seen in the CS group (P = 0.037). VAP occurred in 5 patients of the OS group but in none of the CS group patients (P = 0.037). Spao(2) decreased significantly in the OS group compared with presuctioning values--the opposite of the CS group. Whereas presuctioning values were comparable between groups, postsuctioning Spao(2) was significantly higher in the CS group. CS significantly reduced cross-contamination between bronchial system and gastric juices and reduced the incidence of VAP when compared with OS. Hypoxic phases can be reduced by the help of CS.

Inhibition of Platelet Function by Hydroxyethyl Starch Solutions in Chronic Pain Patients Undergoing Peridural Anesthesia

The use of hydroxyethyl starch (HES) solutions as a fluid replacement before peridural blockade may compromise blood coagulation, thus increasing the risk of neuraxial bleeding. In this prospective, double-blind, placebo-controlled, crossover study, we compared the influence of HES 130 (molecular weight in kilodalton), HES 200, and lactated Ringer's solution on platelet function and hemodynamics in chronic low back pain patients scheduled for peridural blockades. Patients received 3 test infusions of 10 mL/kg each administered IV for 30 min. Collagen/epinephrine and collagen/adenosine diphosphate were used as agonists for assessment of platelet function analyzer-closure times. Arterial blood pressure, heart rate, platelet counts, and hemoglobin levels were documented. Platelet function analyzer-closure times remained stable after lactated Ringer's solution but were significantly prolonged after HES. The platelet-inhibiting effect of HES 200 was more than that of HES 130. Hemodynamic stability was sufficiently maintained by all test infusions. In contrast to previous observations, a relevant antiplatelet effect of both low and medium molecular weight HES solutions was found in this study in chronic pain patients undergoing peridural anesthesia. Because hemostasiological competence is a prerequisite for safe neuraxial blockade, the decision of HES for intravascular fluid administration before blockade should be critically made.

Molecular typing of coagulase-negative staphylococcal blood and skin culture isolates to differentiate between bacteremia and contamination

In order to determine whether a blood culture positive for coagulase-negative staphylococci (CNS) represents bacteremia or contamination, a prospective study was conducted using molecular typing to analyze CNS blood culture isolates and corresponding CNS skin isolates collected after skin disinfection from 431 subjects. CNS bacteremia was not found in any of the 301 subjects not suspected of having bacteremia. In 130 patients suspected of having bacteremia, the rate of actual CNS bacteremia was 6%. The overall rate of CNS blood culture contamination was 1%. Chart analysis showed good agreement between our microbiological definitions of bacteremia and the clinical definitions previously published. Bacteremia and contamination can be differentiated using pulsed-field gel electrophoresis and molecular typing of CNS isolates obtained from cultures of blood and corresponding skin samples.

Monoclonal and biclonal gammopathy in two patients infected with Bartonella henselae

Two immunocompetent patients with cat-scratch disease due to infection with Bartonella henselae developed monoclonal and biclonal gammopathy. Neither patient had evidence of any other known cause of plasma cell dyscrasia, and antibiotic eradication of Bartonella henselae infection resulted in the prompt disappearance of the gammopathy. Hence, cat-scratch disease should be added to the list of possible underlying disorders in individuals presenting with monoclonal and biclonal gammopathy.

Intestinal Candida phospholipase is not elevated in patients with antibiotic-associated diarrhea

In order to assess the role of Candida-secreted phospholipase in antibiotic-associated diarrhea (AAD), 43 fecal Candida isolates from patients with AAD and from controls were tested on egg yolk agar for production of phospholipase. Phospholipase zones did not differ between the isolates from patients with AAD and from controls. The data indicate that the fungal virulence factor phospholipase may not be responsible for AAD in adults.

Omeprazole treatment diminishes intra- and extracellular neutrophil reactive oxygen production and bactericidal activity

OBJECTIVE

Neutrophils play a crucial role in host defense against infectious disease. The objective was to analyze the effect of omeprazole treatment on indexes of neutrophil function in healthy subjects.

DESIGN

Open.

SETTING

University hospital.

SUBJECTS

Ten healthy subjects.

INTERVENTION

Analysis of blood samples before and after omeprazole administration.

MEASUREMENTS AND MAIN RESULTS

Neutrophil Escherichia coli phagocytosis was assessed by microscopy and flow cytometry. Intracellular production of reactive oxygen intermediates was measured by flow cytometry. Extracellular reactive oxygen intermediate production was assessed with a cytochrome c reduction assay. Neutrophil bactericidal capacity and intracellular concentrations of Ca2+ were determined by fluorometry. Four hours after a single 40-mg dose of omeprazole, intra- and extracellular reactive oxygen intermediate production by neutrophils was significantly reduced compared with pretreatment values: -30% (24% to 42%) (median and range) and -22% (21% to 68%; p <.05 for both). The intracellular Ca2+ concentrations in resting neutrophils were significantly increased (+33%, 21% to 39%, compared with pretreatment concentrations, p <.001) and neutrophilic bactericidal activity was decreased (-30%, 19% to 47%, compared with pretreatment concentrations, p <.0001). Intracellular Ca2+ concentrations correlated with intracellular reactive oxygen intermediate production and neutrophilic bactericidal capacity (r =.730 and r =.618, p <.05 for both, respectively). In contrast, phagocytosis rates were not impaired by omeprazole.

CONCLUSIONS

Our results imply that omeprazole impairs production of reactive oxygen intermediates by neutrophils. Whether specific impairments of neutrophil host defenses occur in vivo remains uncertain. Reduced bactericidal activity is associated with an increase of intracellular Ca2+ concentrations in resting neutrophils.

A case of lung transplantation following Mycoplasma pneumoniae infection

Reported here is a case of severe necrotizing pneumonia following Mycoplasma pneumoniae infection that occurred in a 55-year-old man. The histological changes of lung parenchyma included granulomas and bronchiolitis obliterans. Mycoplasma infection was diagnosed by repeated antibody determination (complement fixation test) and confirmed using the polymerase chain reaction to detect the pathogen from a tracheal aspirate. Prior to this episode of pneumonia, the patient had been healthy, except for Reiter's disease that had been diagnosed 18 years previously. In addition to severe pulmonary involvement, the patient developed rhabdomyolysis with subsequent acute renal failure, Stevens-Johnson syndrome, biochemical pancreatitis, severe anemia, and an effusion of the right knee. Contrary to the symptoms of pulmonary disease, all of the extrapulmonary manifestations except anemia were transient. Due to persistent respiratory insufficiency and long-term failure to wean the patient from a respirator, a lung transplantation was performed. Five weeks after transplantation the patient died as a result of intrapulmonary hemorrhage. To the best of our knowledge, this is the first report of pneumonia due to Mycoplasma pneumoniae leading to lung transplantation. Furthermore, the multiple extrapulmonary manifestations in this case make it exceptional.

Role of Candida in antibiotic-associated diarrhea

To quantitatively assess the role of Candida species in antibiotic-associated diarrhea (AAD), stool samples from a total of 395 patients and control subjects were cultured in differential isolation medium: 98 patients had AAD, 93 patients were taking antibiotics but did not have diarrhea (A(+)D(-)), 97 patients were not taking antibiotics but had diarrhea (A(-)D(+)), and 107 patients were control subjects (A(-)D(-)). In addition, secreted aspartyl proteinase (Sap) production was tested. In AAD patients, Candida positivity (77/98) and Candida overgrowth (62/98) were not different from that among A(+)D(-) patients (75/93 [P= .860] and 52/93 [P= .375], respectively). Candida overgrowth among A(-)D(+) patients (40/97, P= .003) was less frequent than among AAD patients, but Candida positivity was not different (80/97, P= .612). In control subjects, Candida positivity and overgrowth were less common than in all other groups. Production of Sap did not differ between patients with AAD and control subjects (P= .568 and P= .590, respectively). Data indicate that elevated Candida counts are a result of antibiotic treatment or diarrhea rather than a cause of AAD.

Severe hemolytic anemia and excessive leukocytosis masking mycoplasma pneumonia

The formation of cold agglutinins is frequently observed during Mycoplasma pneumoniae infections. Nevertheless, severe hemolysis is exceptional. We report a case of life-threatening hemolytic anemia caused by M. pneumoniae. As the leucocyte count was excessively elevated, the differential diagnosis primarily comprised hematological malignancies. The presence of cold agglutinins indicated the correct diagnosis, which was confirmed by highly elevated levels of both IgG and IgM antibodies to M. pneumoniae and a chest X-ray suggestive of atypical pneumonia. The patient was treated with roxithromycin and showed a favorable recovery within ten days after admission. This case demonstrates that, even in patients with clinically mild pneumonia, M. pneumoniae may be the cause of severe anemia.

Effect of vitamin C on neutrophil function after high-intensity exercise

High-intensity exercise leads to an increased risk of upper respiratory tract infections in athletes, which had been related to an exercise-induced impairment of neutrophil function. In this study, several indices of neutrophil function were analysed before and after a biathlon and the effect of oral vitamin C on neutrophil function was determined. Six athletes took 2 g vitamin C daily for 1 week prior to a biathlon and four athletes did not take any supplementation. Neutrophil phagocytosis was analysed by fluorescence microscopy and flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil bactericidal ability was assessed by fluorescence microscopy. Reactive oxygen production was analysed by flow cytometry. Catecholamines were analysed by high-performance liquid chromatography. After high-intensity exercise there were significant reductions in the number of phagocytosed Escherichia coli per neutrophil and in neutrophil bactericidal ability. There was a significant exercise-dependent increase of catecholamines. There was no difference between the two groups of athletes. These results do not support the concept that vitamin C supplementation corrects neutrophil dysfunction after strenuous exercise.

The effect of fosfomycin on neutrophil function

Fosfomycin (cis-1,2-epoxypropyl phosphonic acid) is a cell wall synthesis-inhibiting antibiotic. We investigated the effect of fosfomycin on several indices of neutrophil function. Neutrophil phagocytosis was analysed by flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil bactericidal ability was assessed by fluorescence microscopy. Intracellular reactive oxygen intermediate (ROI) production was analysed by flow cytometry and extracellular ROI by cytochrome c reductase assay. After fosfomycin incubation, phagocytosis was unaffected as assessed by the FACS assay. Fosfomycin incubation resulted in enhanced bactericidal ability, in increased intracellular calcium concentrations, elevated extracellular ROI production and decreased chemotaxis but it did not affect intracellular ROI production and chemokinesis.

Osteomyelitis of the hip joint associated with systemic cat-scratch disease in an adult

Reported here is the case of a 29-year-old male with cervical lymphadenopathy, fever and weight loss, followed by acute painful osteomyelitis of the left hip joint due to cat-scratch disease. The diagnosis was established by detection of IgG antibodies to Bartonella henselae in serum and histologic examination of a lymph node including a positive polymerase chain reaction test. Treatment consisted of clarithromycin and cefotiam for 2 weeks. Four weeks after discharge, all of the patient's symptoms had completely resolved. Magnetic resonance imaging of the left hip joint showed marked regression of bone inflammation 4 months later and normalization after 8 months. Cat-scratch disease should be considered in the differential diagnosis of osteomyelitis in an adult, especially when lymphadenitis is present.

Serum concentrations of granulocyte-colony stimulating factor in complicated Plasmodium falciparum malaria

Involvement of neutrophils in the control of blood parasites in malaria has been reported. Both, mononuclear phagocytes and neutrophils are known to be stimulated by cytokines such as TNF-alpha in order to augment the defence potency against the parasites. Previously, it has been shown that serum-G-CSF concentrations are increased in patients with bacterial sepsis. In vitro studies have shown that P. falciparum - infected erythrocytes induce the release of G-CSF by several cells such as endothelial cells and monocytes, however, nothing is known about G-CSF serum concentrations during the clinical course of severe P. falciparum malaria. Thus, it was the aim of the present study to investigate the time course for G-CSF serum concentrations in patients with complicated P. falciparum malaria, and to correlate these values with other mediators of inflammation and hematopoesis. Twenty-six patients suffering from complicated P. falciparum malaria were included in the study, and 20, age and sex matched, healthy volunteers were used as the negative control group. Serum samples for determination of G-CSF were taken on day 0, 7 and 14, and measured by ELISA. We found significantly increased serum concentrations of G-CSF in patients with complicated P. falciparum malaria on day 0, values decreasing to within the normal range by day 7. A significant correlation was found between G-CSF (d0) and procalcitonin, the parasite count, erythropoietin and macrophage inflammatory protein, however no correlation could be shown for the neutrophil count. In conclusion, on the day of hospital admission, elevated serum concentrations of G-CSF were detected in patients with complicated P. falciparum malaria, which might indicate a role of G-CSF in the acute defence mechanism against the parasites.

Homocysteine and laminin are not prognostic markers in patients with septic inflammatory response syndrome

The aim of this study was to measure plasma homocysteine and laminin concentrations in patients with nonbacteremic systemic inflammatory response syndrome (SIRS) and to compare them with those of a healthy control group. Concerning laminin, significant increased concentrations could be observed in the SIRS group compared to the control group, but for homocysteine, no significance could be observed. In summary, homocysteine and laminin levels are not useful in the prediction of a patient's outcome.

Effect of age on human neutrophil function

Neutrophil phagocytosis, reactive oxygen intermediate production (intra- and extracellular), neutrophil bactericidal activity, and chemotaxis/chemokinesis were assessed in three age groups: 21-36, 38-56, and 62-83 years. A significant age-dependent reduction in the number of phagocytized Escherichia coli per neutrophil (measured by acridine orange staining) and Staphylococcus aureus phagocytosis (measured by flow cytometry) was seen (r = 0.669 and r = 0.684, P<0.001 for both). These findings correlated with an age-dependent increase in intracellular calcium concentrations in resting neutrophils (r = 0.698, P<0.001) and a reduced hexose uptake (r = 0.591, P<0.01). In addition, a significant reduction in the intracellular reactive oxygen production was seen after stimulation with S. aureus (P<0.001) with increasing age. In contrast, no differences between the groups in reactive oxygen production was seen after stimulation with E. coli. The neutrophil bactericidal activity was impaired with increasing age (64+/-4% of the phagocytized bacteria were killed in group 1; 66+/-2 in group 2, and 59+/-6 in group 3; P<0.01). In addition, a trend toward a reduced neutrophil chemotaxis was seen with increasing age (P = 0.022). The findings suggest that increased intracellular calcium concentrations in resting neutrophils and/or a reduced hexose uptake result in reduced phagocytic ability and decreased bactericidal activity of neutrophils in the elderly.