Helicobacter cinaedi septic arthritis and bacteremia in an immunocompetent patient.

We report on the first case of documented Helicobacter cinaedi septic arthritis in an immunocompetent heterosexual young man. The patient presented no identified risk factor except for contact with animals that have been incriminated as a possible source of infection, particularly for these patients. Despite prolonged bacteremia, the response to long-term therapy with ciprofloxacin and rifampin was excellent.

Safety, efficacy, and cost-effectiveness of mechanical ventilation with humidifying filters changed every 48 hours: a prospective, randomized study.

OBJECTIVE: To determine whether three hydrophobic and hygroscopic heat and moisture exchangers (HMEs) retain their heating and humidifying properties (assessed by psychrometric measurements of absolute humidity, relative humidity, and tracheal temperature) for 48 hrs without any drop in their bacteriologic efficiency. DESIGN: Prospective randomized clinical trial. PATIENTS: Sixty-one consecutive unselected mechanically ventilated intensive care unit patients. INTERVENTIONS: Patients were randomly allocated to one of the three HMEs studied (Hygrobac-Dar from Mallinckrodt, n = 21; Humid-Vent from Gibeck, n = 20; and Clear-Thermal from Intersurgical, n = 20). MEASUREMENTS AND MAIN RESULTS: Hygrometric parameters were measured by psychrometry after 3, 24, and 48 hrs of use. Peak airway pressure was recorded every 6 hrs and averaged over 24 hrs. Bacterial colonization of both patients and circuits was studied. Patients in all three groups were similar in terms of age, indications for, and overall duration of mechanical ventilation. Tracheal tube occlusion never occurred. Hygrometric data included 371 measurements whereas bacteriologic data included >700 samples and cultures. The Hygrobac-Dar HMEs gave a significantly higher absolute humidity whatever the time of measurement (3, 24, or 48 hrs) than the other two HMEs (p < .001). The Clear-Thermal HMEs gave the poorest hygrometric parameters (p < .01); five of them were replaced prematurely (24 hrs) because the absolute humidity was <25 mg H2O/L. This did not occur for the other HMEs. Mean peak airway pressures were identical in the three groups. The bacterial colonizations of both patient and circuit were similar (and negligible for circuits) for all three groups. CONCLUSION: Some HMEs may be used safely for 48 hrs without change. However, this does not pertain to every brand of HME. Objective in vivo evaluation of their humidifying performances is decisive before extending their duration of use.

[Pancytopenia in acute brucellosis]. / Pancytopénie au cours d'une brucellose aiguë.

Leuconeutropenia is a common manifestation of acute brucellosis, whereas other hematological abnormalities and pancytopenia are uncommon. We report a patient presenting with acute brucellosis and pancytopenia.

Prevalence and pathogenicity of Clostridium difficile in hospitalized patients. A French multicenter study.

BACKGROUND: Although Clostridium difficile is the main agent responsible for nosocomial diarrhea in adults, its prevalence in stool cultures sent to hospital microbiology laboratories is not clearly established. OBJECTIVES: To determine the prevalence of C difficile in inpatient stools sent to hospital microbiology laboratories and to assess the relationship between serotypes and toxigenicity of the strains isolated and the clinical data. METHODS: From January 18, 1993, to July 31, 1993, the presence of C difficile was systematically investigated in a case-control study on 3921 stool samples sent for stool culture to 11 French hospital microbiology laboratories. The prevalence of C difficile in this population (cases) was compared with that of a group of 229 random hospital controls matched for age, department, and length of stay (controls). Stool culture from controls was requested by the laboratory although not prescribed by the clinical staff. Serotype and toxigenesis of the strains isolated were compared. RESULTS: The overall prevalence of C difficile in the cases was twice the prevalence in the controls (9.7% vs 4.8%; P < .001) and was approximately 4 times as high in diarrheal stools (ie, soft or liquid) as in normally formed stools from controls (11.5% vs 3.3%; P < .001). The strains isolated from diarrheal stools were more frequently toxigenic than those isolated from normally formed stools. Serogroup D was never toxigenic, and its proportion was statistically greater in the controls than in the cases (45% vs 18%; chi 2 = 5.2; P < .05). Conversely, serogroup C was isolated only from the cases. Clostridium difficile was mainly found in older patients ( > 65 years), suffering from a severe disabling disease, who had been treated with antibiotics and hospitalized for more than 1 week in long-stay wards or in intensive care. CONCLUSIONS: This multicenter period prevalence study clearly supports the hypothesis of a common role of C difficile in infectious diarrhea in hospitalized patients. Disease associated with C difficile should therefore be systematically evaluated in diarrheal stools from inpatients.

Changing heat and moisture exchangers every 48 hours rather than 24 hours does not affect their efficacy and the incidence of nosocomial pneumonia.

Heat and moisture exchangers (HME) (Dar-Hygrobac II, Peters) can safely be used every 24 h for long-term mechanical ventilation and provide a cost-saving alternative to heated humidifiers. We have prospectively determined whether changing HMEs every 48 h only affects their clinical and bacteriological efficiency in a series of consecutive nonselected ICU patients requiring long-term mechanical ventilation. Two consecutive periods were compared. During period 1, HMEs were replaced every day; during period 2, they were changed every 48 h. Patients from the two periods were similar in terms of age and indication for and overall duration of MV (10 +/- 8.6 versus 10 +/- 9 d, p = 0.9). Minute ventilation and maximum values for peak airway pressure were identical during the two periods. These values were also identical after 1 and 2 d of HME use during period 2, indicating that HME resistance was not increased by prolonged use. Obstruction of the tracheal tube occurred only once in a period 1 patient. The results of quantitative cultures indicate that the maximum and mean levels of bacterial colonization during the two periods were similar for the pharynx, trachea, Y-connector, patient, and ventilator side of the HME. More importantly, the incidence of nosocomial pneumonia was similar during the two periods (6/61 versus 8/68, p = 0.7). Thus, prolonged HME use is safe and provides a substantial reduction in the cost of mechanical ventilation.

Mechanical ventilation with heated humidifiers or heat and moisture exchangers: effects on patient colonization and incidence of nosocomial pneumonia.

The contribution of ventilator circuit bacterial contamination to the occurrence of ventilator-associated pneumonia remains controversial. In a previous study, we found that the incidence of pneumonia was identical with ventilator circuit changes every 48 h and with no ventilator circuit changes. The present study prospectively assessed whether keeping ventilator circuits clean with a heat and moisture exchanger exhibiting antimicrobial barrier properties affects patient colonization and the incidence of nosocomial pneumonia in patients receiving mechanical ventilation for more than 48 h. Consecutive patients were randomly allocated to humidification with either a heat and moisture exchanger (Group 1, n = 61) or a heated humidifier (Group 2, n = 70). In both groups, no circuit changes were performed throughout ventilatory support. Duration of mechanical ventilation was identical in both groups (10 +/- 8.6 d (range: 2 to 47) in Group 1 and 12.5 +/- 14.2 d [range: 2 to 85] in Group 2). The incidence of pneumonia (positive quantitative culture of protected brush specimen) was similar in both groups (6/61 and 8/70 in Groups 1 and 2, respectively; p = 0.8), as was duration of ventilation prior to pneumonia (9 +/- 5.9 versus 8.2 +/- 5.7 d; p = 0.8). Ventilator tubing contamination was considerably reduced with the use of a heat and moisture exchanger. In contrast, bacterial colonization of the pharynx and trachea was identical in both groups. These results suggest that circuit colonization plays little or no role in the occurrence of ventilator-associated pneumonia, provided usual maintenance precautions are applied.(ABSTRACT TRUNCATED AT 250 WORDS)

[Osteoarticular tuberculosis. Diagnostic contribution of local sampling]. / Tuberculose ostéoarticulaire. Apport diagnostique du prélèvement local.

Bone and joint tuberculosis have recently gained a renewal of interest, especially with the spread of HIV infection which may increase its frequency. Bone and joint locations of tuberculosis are pauci-bacillary often requiring local sampling in order to confirm the diagnosis and to initiate early therapy. From 1983 to 1992 we have studied 19 patients with bone and joint tuberculosis. Seventeen local sampling were performed: 12 biopsies and five abscess punctures. Pathological examination of samples disclosed diagnosis of tuberculosis in eight cases out of 12. Among the remaining four patients, direct smear was positive once, and cultures grew Mycobacterium tuberculosis in two, yielding the diagnosis in 11 out of the 12 patients. Bacteriological and pathological examinations were non contributive in only one patient. Microbiological examination of pus disclosed two positive direct smear and three positive cultures. Treatment lasted 9 to 18 months. The outcome was favourable in all patients.

Clinical significance of borderline quantitative protected brush specimen culture results.

In patients with clinical suspicion of pneumonia, quantitative cultures of protected brushing specimens (PBS) yielding > or = 10(3) CFU/ml of at least one microorganism have been found useful for differentiating airway colonization and lung infection, especially in mechanically ventilated patients. The amount of secretions collected by protected catheter brushing is small and difficult to determine accurately. Thus, the clinical significance of PBS cultures yielding organisms in concentrations > or = 10(2) but < 10(3) CFU/ml, in the absence of active antimicrobial treatment, is unknown. The 34 consecutive results of PBS cultures yielding organisms in concentrations > or = 10(2) but < 10(3) CFU/ml in 30 patients under mechanical ventilation or weaned for < or = 4 days were prospectively studied. No patients were receiving agents active on the organism recovered. In 5 cases, the diagnosis of pneumonia was ruled out by recovery without treatment (n = 4) or negative postmortem lung cultures (n = 1). A second PBS was cultured in 29 episodes (2.7 +/- 1.8 days after the first PBS). In 12 instances (Group 1), cultures of the second PBS yielded > or = 10(3) CFU/ml of the same organism as that found in the first PBS (S. pneumoniae, 1; S. aureus, 1; H. influenzae, 1; E. coli, 1; P. aeruginosa, 4; and A. baumannii, 4), and these patients were therefore treated with appropriate antibiotics. A total of 17 patients had a negative repeat PBS culture (no growth or trivial concentrations) and were considered free of pneumonia and given no antibiotic treatment for this episode.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of primary tuberculosis in children by amplification and detection of mycobacterial DNA.

Standard microbiologic techniques were compared with a rapid diagnostic method based on the amplification by polymerase chain reaction (PCR) of a fragment of the IS6110 insertion element (present in multiple copies in the Mycobacterium tuberculosis genome) for the detection of M. tuberculosis in specimens obtained from children diagnosed as having primary tuberculosis on clinical grounds. Two (n = 7) or three (n = 15) gastric aspirates were obtained from the 22 children with primary tuberculosis. All specimens were negative for mycobacteria by acid-fast staining and culture. When DNA was purified from the clinical specimens and aliquots of each sample were amplified in duplicate, 15 of 59 (25%) specimens gave at least one positive result. Increasing beyond two the number of times that samples were tested did not appreciably improve sensitivity. Testing multiple samples from the same individual increased the diagnostic yield. Thus, when three different samples from the same subject were tested two times each, two or more positive results were obtained from 9 of 15 children with primary tuberculosis but 0 of 17 control subjects. Samples from children with symptoms, recent contact with patients with active tuberculosis, vesicular tuberculin responses, or abnormal chest radiographs were more frequently positive than those from patients whose only manifestation of tuberculosis was a positive (but not vesicular) tuberculin response. Thus, M. tuberculosis DNA can be detected by PCR in gastric aspirates of many children with primary tuberculosis, despite that specimens from these patients are negative by culture. Multiple samples must be tested to optimize the diagnostic yield.

[Neonatal digestive implantation of streptococcus group B. Influence of antibiotic therapy]. / Implantation digestive néonatale du streptocoque B. Influence de l'antibiothérapie.

Group B streptococcus (GBS) is an important cause of neonatal infection. Early-onset diseases are due to perinatal contamination. The epidemiology of late-onset infections is poorly known. Maternal colonization may be responsible for some of them. The relationships between neonatal colonization and late disease could be a colonization of the gut. The purpose of this 3 year-prospective study was to analyse the kinetics of gut colonization in neonates and the influence of antibiotherapy. One hundred and nineteen infants less than one month of age were included because of the presence of GBS in their gastric aspirates or GBS infection. Depending on the therapeutic strategy, the infants were separated into 3 groups: 1) amoxicillin plus aminoside greater than or equal to 10 days because of neonatal infection (28 infants), 2) same combination less than or equal to 5 days because a GBS infection was suspected but not confirmed (17 infants), 3) no antibiotics (77 infants). Fecal flora was regularly analysed by differential count. Antibiotics caused rapid disappearance of GBS from the gut. However, the same strain reappeared after stopping the antibiotics at a rate of 13.5%. Without antibiotics, GBS was implanted in 33% of cases. This difference of implantation rate is statistically significant (p less than 0.05). No GBS infection was observed in any infant after a follow-up examination of 6 months to 2 years. Among the clinical and bacteriological factors studied, adhesion only was correlated with the GBS implantation. These results allow to discuss therapeutic abstention in colonized infants without any signs of infection.

Use of a reamplification protocol improves sensitivity of detection of Mycobacterium tuberculosis in clinical samples by amplification of DNA.

We have compared the sensitivity and specificity of quantitative mycobacterial culture against results obtained by using the polymerase chain reaction for the detection of DNA from organisms of the Mycobacterium tuberculosis complex in 82 clinical specimens from patients suspected of having tuberculosis. Two amplification protocols were used, a standard amplification protocol, which amplifies a segment of the gene coding for the 65-kDa antigen, and a protocol in which the initial amplification products are reamplified with a second set of nested oligonucleotide primers. Although the standard amplification protocol gave positive results for 18 of 18 samples which grew greater than 100 CFU/ml and gave positive results in 4 of 35 specimens from patients with tuberculosis which were negative by culture, only 1 of 6 samples which grew less than 100 CFU/ml was positive. This lack of sensitivity could not be explained by the presence of inhibitors of Taq polymerase present in the original samples. In contrast, the reamplification protocol gave positive results for 24 of 24 samples which were positive by culture as well as for 13 of 35 samples from patients with tuberculosis which were negative by culture (overall sensitivity, 63%, P less than 0.02, compared with the standard amplification protocol and routine culture). Two of 23 samples from patients not diagnosed as having tuberculosis gave positive results when the standard amplification protocol was used, but no additional false-positive results were seen with the reamplification protocol (overall specificity, 91%). We conclude that the use of a reamplification protocol improves the sensitivity of detection of mycobacterial DNA in clinical samples without sacrificing specificity. The sensitivity of this approach appears to be superior to that of standard culture techniques.

Prospective study of nosocomial pneumonia and of patient and circuit colonization during mechanical ventilation with circuit changes every 48 hours versus no change.

Circuits on mechanical ventilators with cascade humidifiers are routinely changed every day or every other day, although humidifying cascades have been considered unlikely to increase the risk of respiratory infection because they do not generate aerosols. Moreover, changing ventilator tubings every 24 rather than every 48 h increases the risk of ventilator-associated pneumonia. To study the effects of ventilator circuit changes on the rate of nosocomial pneumonia and on patient and circuit colonization, 73 consecutive patients requiring continuous mechanical ventilation for more than 48 h were randomly assigned to either ventilator circuit changes every 48 h (Group 1, n = 38) or no change (Group 2, n = 35). Patients dying or being weaned before 96 h were not analyzed (Group 1 n = 3; Group 2 n = 7; leaving Group 1 n = 35 and Group 2 n = 28; p = 0.13). Ventilator-associated pneumonia was defined as the occurrence during mechanical ventilation or within 48 h after weaning of a new and persistent infiltrate on chest X-ray, purulent tracheal secretions, and a positive culture of a protected brush specimen (greater than or equal to 10(3) cfu/ml). Bacterial colonization was assessed every 48 h by quantitative cultures of pharyngeal swab, tracheal aspirate, humidifying cascade, and expiratory tubing trap. The two groups were similar in terms of age, indication for and duration of ventilation, and severity of illness.(ABSTRACT TRUNCATED AT 250 WORDS)

In-vitro activity of cefpodoxime against pathogens responsible for community-acquired respiratory tract infections.

The in-vitro activity of cefpodoxime, the active compound of the ester prodrug, cefpodoxime proxetil, was compared with that of other antibiotics. The susceptibility of bacterial isolates from patients with respiratory tract infections was determined by an agar dilution method. The MIC90s of cefpodozime for ampicillin-sensitive and beta-lactamase-producing strains of Haemophilus influenzae were 0.12 and 0.25 mg/l, respectively; the MIC90s for ampicillin-resistant non-beta-lactamase-producing strains was 1 mg/l. Time-kill curves of cefpodoxime against ampicillin-sensitive and ampicillin-resistant beta-lactamase producing strains showed a time-dependent bactericidal activity. The MIC90s for ampicillin-sensitive and ampicillin-resistant Branhamella catarrhalis were 0.50 and 1 mg/l, respectively. The MIC90s for penicillin-sensitive pneumococci, beta-haemolytic streptococci and Streptococcus agalactiae were 0.06, 0.06 and 0.12 mg/l, respectively. The inhibitory activity against penicillin-resistant pneumococci was limited: the MIC90 was 4 mg/l.