Antimicrobial resistance and epidemiological study of Haemophilus influenzae strains isolated in Portugal. The Multicentre Study Group

In the course of a multicentric surveillance study, nine laboratories sent 375 isolates of Haemophilus influenzae to the Sector de Resistência aos Antibióticos (SRA) from the National Institute of Health in Lisbon, between 1 January and 31 December 1992. The majority of the H. influenzae isolates were from the respiratory tract (84.8%); only 5.1% were of invasive origin. Overall resistance for ampicillin was 11.7%, tetracycline 3.7%, and chloramphenicol 2.4%. All isolates tested were fully susceptible to cefotaxime, ceftriaxone, ciprofloxacin and rifampicin. Multiresistance was rare, occurring only in 2.4% of the isolates, although 50% of the ampicillin resistant strains had at least one additional resistance marker. Forty two isolates (11.2%) produced a TEM-1 type beta-lactamase, as shown by isoelectric focusing. beta-lactamase production was not detected in two of the ampicillin resistant strains. Fifteen of the 42 beta-lactamase producing strains (35.7%) contained detectable DNA plasmid: nine harboured large plasmids with an apparent molecular mass of 45 or 54 kb depending on their resistance phenotype and six harboured a small plasmid of 5 kb. In order to study transfer of resistance in both ampicillin and multiresistant strains conjugation experiments were performed for 14 isolates, seven of which harboured a large plasmid and seven had no detectable plasmid DNA. All 14 transferred their resistance phenotype but only a single large plasmid could be demonstrated in ten transconjugants. Restriction endonuclease analysis of plasmids from six representative transconjugants, isolated in different hospitals, revealed that there was no dissemination of a single R plasmid, which suggests an independent process of acquisition of resistance genes.

[Sexually transmitted diseases in men]

Sexually transmitted diseases (STD) constitute a frequent presenting complaint. The epidemiology of human immunodeficiency virus (HIV) infection is identical to that of STD and must therefore be systematically investigated in the presence of any STD. Chlamydia trachomatis (CT) is involved in the majority of cases of urethritis and epididymitis in young subjects and is present in the urethra of 10% of subjects with a genital ulcer. Genital ulcers are due to either Treponema Pallidum, Haemophilus ducreyi, or Herpes simplex virus: there is little clinicobacteriological correlation and it is therefore essential to perform laboratory examinations in order to establish the diagnosis. The prevalence of venereal vegetations due to HPV viruses has increased markedly over recent years and require effective treatment and surveillance because of the risk of carcinoma induced by viral oncogenesis. Other viral diseases such as hepatitis B are also classified as STD. The main diagnostic techniques used at the present time for each STD are reviewed and the consensually accepted therapeutic protocols are also proposed.

Genotypic identification of two groups within the species Bacteroides fragilis by ribotyping and by analysis of PCR-generated fragment patterns and insertion sequence content

Molecular typing allowed the separation of the species Bacteroides fragilis into two genotypically distinct groups. A unique set of 50 strains of B. fragilis carrying the chromosomal metallo-beta-lactamase gene cfiA was subjected to a comparative analysis with respect to sets of up to 250 randomly collected strains devoid of this gene. The two groups were found to be distinct on the basis of the following results: (i) ribotyping, after DNA digestion with AvaI, revealed a practically homogeneous DNA fragment pattern for the cfiA-positive strains and distinct multiple patterns for the cfiA-negative strains; (ii) PCR, arbitrarily primed with an experimentally selected decamer, generated fragment patterns typical for the strains of each group; (iii) the three insertion sequences described to date in the species B. fragilis, i.e., IS4351, IS942, and IS1186, were all but confined to the cfiA-positive group, in which they were capable of providing promoter sequences for the transcription of cfiA; and (iv) the cepA gene, encoding the so-called endogenous cephalosporinase of B. fragilis, was found exclusively in the cfiA-negative group, in which it was present in ca. 70% of the strains. The cfiA-, cepA-negative fraction was not characterized further. In a natural population of 500 randomly selected strains of B. fragilis, the cfiA-positive and cfiA-negative groups represented ca. 3 and 97% of the strains, respectively. Analysis of 82 metabolic traits revealed no difference between the two groups.

Campylobacter infections in HIV-infected patients: clinical and bacteriological features

OBJECTIVE

To study the clinical and bacteriological features of Campylobacter infections in HIV-infected patients.

DESIGN

A retrospective analysis (1989-1992), followed by a prospective analysis (1992-1994).

SETTING

Hospital HIV inpatient unit.

PATIENTS AND METHODS

All patients with Campylobacter spp. identified by the laboratory of microbiology at Saint-Louis Hospital, Paris were studied, and their clinical features as well as their response to therapy recorded.

RESULTS

During the study period, Campylobacter infection was documented in 38 HIV-infected patients, 76% of whom had AIDS. Campylobacter spp. was isolated from stools in 36 cases and from blood cultures in four cases. Species identification yielded C. jejuni (84%) and C. coli (16%). High-level resistance to quinolones was frequently observed (21%), but resistance to erythromycin (3%) and tetracycline (5%) was rare. Diarrhoea, fever and abdominal pain were the main clinical features of infection. Other intestinal pathogens were found in 42% of patients. Most patients had an acute illness with rapid resolution under appropriate antimicrobial therapy. However, eight patients (21%), experienced chronic diarrhoea with persistent isolation of Campylobacter and in vivo selection of resistant strains, requiring multiple courses of antibiotics.

CONCLUSIONS

Campylobacter usually cause acute diarrhoea in patients with HIV infection. Antimicrobial therapy should be guided on in vitro susceptibility testing because of the prevalence of antibiotic resistance. Despite appropriate therapy, some patients will present with prolonged diarrhoea and in vivo selection of multiresistant isolates.

Male urethritis with and without discharge: a clinical and microbiological study

BACKGROUND

The definition of male urethritis in the absence of urethral discharge has not been well established. The sensitivity of urethral swabs and first-catch urine is controversial.

GOAL OF THIS STUDY

To correlate clinical data (discharge or not), urethral swabs, and first-catch urine examinations with the microorganisms found within the urethra in a cohort of men attending the sexually transmitted disease clinic of Hôpital Saint Louis (Paris) for treatment of urethral symptoms with or without discharge.

STUDY DESIGN

Two-hundred-seventy-three consecutive male patients entered this prospective study between October 1, 1992 and November 30, 1992. Fifty-two patients were excluded because they had been treated with antibiotics in the previous 3 months. All patients were screened for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Ureaplasma urealyticum, Mycoplasma hominis, and Candida albicans.

RESULTS

Two-hundred-nineteen patients were eligible for the study (122 with discharge and 97 with no discharge). The prevalence of microorganisms was as follows: Chlamydia trachomatis in 13%, Neisseria gonorrhoeae in 11%, Ureaplasma urealyticum in 7%, Mycoplasma genitalium in 17%, Trichomonas vaginalis in 1%, and indeterminate pathogens alone in 20%. All major pathogens and Mycoplasma genitalium were more common in patients with discharge. Stratification of results according to the presence of polymorphonuclear leukocytes on the urethral swab and first-catch urine showed a low sensitivity of both tests for Chlamydia trachomatis (29%), Mycoplasma genitalium (50% and 62%), and Ureaplasma urealyticum (33%) in patients with no discharge.

CONCLUSION

A specific and sensitive search for Chlamydia trachomatis should be done in every patient with urethral symptoms whether or not the classic symptoms of urethritis are present (discharge, presence of polymorphonuclear leukocytes in the urethra or first-catch urine).

Molecular epidemiology of Klebsiella pneumoniae strains that produce SHV-4 beta-lactamase and which were isolated in 14 French hospitals

Preliminary results suggested that the diffusion in France of the SHV-4 extended-spectrum beta-lactamase was probably due to the spread of one single epidemic strain of Klebsiella pneumoniae. In this study, we tested various phenotypic and genotypic markers to compare K. pneumoniae strains producing this enzyme isolated in 14 French hospitals between 1987 and 1989. All of the strains were of the same capsule serotype, K25. Twelve of them were of the same biotype: weak urease activity and no sucrose fermentation. Among the six plasmid profiles observed, one accounted for eight strains. Large plasmids of 170 kb encoding SHV-4 beta-lactamase were present in all strains of K. pneumoniae and could be transferred by conjugation with high frequency to Escherichia coli J53-2 or HB101 from all except one strain. Plasmid EcoRI restriction patterns suggested that these plasmids were closely related and similar to pUD18 encoding SHV-3 beta-lactamase, originally described in France and differing from SHV-4 by one amino acid substitution. Ribotyping with EcoRI and HindIII and genomic fingerprinting with XbaI by pulsed-field gel electrophoresis were concordant and suggested that 12 of the isolates recovered from the 14 hospitals were probably the same strain. Dissemination in France of the SHV-4 extended-spectrum beta-lactamase was thus essentially due to the diffusion of a single K. pneumoniae clone.

[Beta-lactamase-producing Haemophilus influenzae isolated in Portugal, 1989-1992]

Within the framework of a national multicentric study between 1989 and 1992, 118 strains of betalactamase producing Haemophilus influenzae were isolated. Biotyping demonstrated the predominance of biotypes I, II and III, with 22, 36 and 24% of the strains, respectively. Encapsulated strains accounted for 13% of the total; all, but one, were serotype b. The antimicrobial susceptibility test (dilution method) of the 118 ampicillin--resistant strains showed: 33.9% resistance to tetracycline, 29.7% to chloramphenicol, 10.2% to erythromycin, 9.3% to trimethoprim, 0.8% to rifampicin, and 29.7% of multiresistance. All strains were susceptible to augmentin, cefotaxime, ceftriaxone and ceprofloxacin. Ninety strains were screened for resistant plasmids. A large plasmid (30-50 Mdal) was isolated in 38.9% of the strains and a small plasmid (3-4.4 Mdal) in 10%. No plasmid was found in 51% of the strains. Isoelectric focusing of 54 beta-lactamases showed that all were type TEM-1 (pI = 5.4), with the exception of one, which was type TEM-2 (pI = 5.6).

Risk factors for Clostridium difficile-associated diarrhoea in HIV-infected patients

OBJECTIVE

To identify risk factors associated with a first episode of Clostridium difficile-associated diarrhoea (CDAD) in patients with HIV infection.

DESIGN

A case-control study.

SETTING

University teaching hospital HIV inpatient unit.

PATIENTS AND METHODS

Nineteen HIV-infected patients with CDAD, defined as diarrhoea with positive stool culture for Clostridium difficile (CD) and positive stool cytotoxin B assay, were compared with 38 randomly selected controls (HIV-infected patients hospitalized on the ward on the day the matched case was diagnosed). CD isolates were phenotyped by electrophoretic protein patterns.

RESULTS

The incidence of CDAD among HIV-infected patients was 4.1/100 of patient-admissions. On univariate analysis, cases were more likely to have used clindamycin [11 out of 19 compared with four out of 38; odds ratio (OR) 19; 95% confidence interval (CI), 2-160; P = 0.0007], and pyrimethamine (14 out of 19 compared with 13 out of 38; OR, 4.8; 95% CI, 1.4-16, P = 0.02) in the month before diagnosis, and to have had cerebral toxoplasmosis (12 out of 19 compared with 13 out of 38; OR, 2.8; 95% CI, 0.9-8.6; P = 0.09). There was also a significant increase of the risk of CDAD as duration of hospitalization in the ward increased (chi 2 for trend, P = 0.007). Multivariate models associated two risk factors with CDAD: clindamycin use (OR, 42; 95% CI, 2-813; P = 0.01), and prolonged hospitalization in the ward (OR, 3.6 per week in the ward; 95% CI, 1-13, P = 0.048). Of 18 available CD isolates, 15 (83%) had identical electrophoretic protein pattern.

CONCLUSIONS

Clindamycin use and prolonged hospitalization in the ward were the main risk factors associated with CDAD in this study. These observations, together with the occurrence of one major phenotype of CD, suggest nosocomial transmission of CD in the ward.

Intestinal microsporidiosis in human immunodeficiency virus-infected patients with chronic unexplained diarrhea: prevalence and clinical and biologic features

Eighteen patients infected with human immunodeficiency virus and with chronic unexplained diarrhea were prospectively studied to investigate the prevalence and clinical and biologic features of intestinal microsporidiosis. All patients underwent extensive evaluation for bacterial, viral, and parasitic pathogens. Enterocytozoon bieneusi was found in 9 patients (50%; 95% confidence interval, 27-73) in stools and duodenal and jejunal biopsies. In 8 patients, it was the sole pathogen found. Other pathogens were also isolated from the intestinal tracts of 4 patients, but diarrhea remained unexplained in 6. Patients with intestinal microsporidiosis had significantly lower mean Karnofsky scores (69.4 vs. 85.5, P = .009), CD4 cell counts (18.6 vs. 209.8/microL, P = .02), and D-xylose absorption tests (0.13 vs. 0.36 g/L, P < .001) than did patients without intestinal microsporidiosis. Intestinal microsporidiosis appears to be a frequent cause of unexplained chronic diarrhea in patients with AIDS and is associated with diminished D-xylose absorption.

[Microbiological study of male genital ulcers. Apropos of 75 cases]

Between November 1986 and June 1987, the microbial aetiology of genital ulcers was assessed in 75 male patients attending the Sexually Transmitted Disease (STD) clinic in Hôpital Saint-Louis, Paris. Evidence of Haemophilus ducreyi was found in 18 patients (24%), Herpes simplex virus in 19 (25.3%). Syphilis was diagnosed on the basis of dark field microscopy and/or positive serology test in 19 patients (25.3%). Lymphogranuloma venereum was not diagnosed in any patient. Primary pathogens were not identified from the remaining 19 (25.3%) men. Neisseria gonorrhoea was isolated in five patients, from the ulcer in three cases, from the urethra in two. Asymptomatic urethral carriage of Chlamydia trachomatis was culture proven in seven cases. The presence of IgM antibodies to C. trachomatis at a titre greater than 40 found in 17 patients was a indication of a current chlamydial infection. Three patients (4%) were discovered to be HIV-1 positive.

Lymphogranuloma venereum: 27 cases in Paris

Twenty-seven men with laboratory-confirmed lymphogranuloma venereum (LGV) were identified among 211 patients tested for LGV or chancroid during a 6-y period. The patients with LGV ranged in age from 17 to 73 y; most were from countries other than France. Twenty-five sought care because of inguinal adenopathy (with spontaneous draining fistulae in two patients) and two because of proctitis. Chlamydia trachomatis was isolated from nine patients; all isolates were the LGV biovar as demonstrated by biologic characterization and monoclonal antibody reactivity. In patients without isolation of C. trachomatis, the diagnosis was based on chlamydial complement fixation antibody titers greater than or equal to 1:32 (mean titer, 1:128). Genital herpes was an associated diagnosis in one patient and syphilis in two patients. Serologic evidence of exposure to human immunodeficiency virus (HIV) type 1 was present in five patients and to HIV-2 in one patient.

Serum antibody response to the 70,000-molecular-weight neisserial common antigen in humans infected by Neisseria gonorrhoeae

We evaluated the presence of antibodies directed against a 70,000-molecular-weight (70K) common neisserial antigen in sera from patients with first or repeated gonococcal infections and in sera from healthy controls. Sera were taken as soon as possible after the onset of disease, and anti-70K antibodies were detected by Western blot (immunoblot). Results show that significantly fewer patients with gonococcal infection possessed anti-70K antibodies than controls (P less than 0.001). This suggests a possible role of anti-70K antibodies in natural immunity against Neisseria gonorrhoeae.

Rapid determination of MICs of 15 antichlamydial agents by using an enzyme immunoassay (Chlamydiazyme)

An enzyme immunoassay (EIA), Chlamydiazyme (Abbott Laboratories), was evaluated for its determination of MICs of 15 antimicrobial agents against Chlamydia trachomatis (MRC-1, LB, TRIC/GB/MRC-1 Gf [ATCC VR-1]). The inoculum size, incubation time, and enhancers were defined for the assessment of chlamydial antigen synthesis in HeLa 229 cells seeded as monolayers in 96-well plates. MICs were determined and defined as the lowest antibiotic concentrations required to inhibit, after 24 or 48 h of incubation, antigen production as determined by the EIA. The MICs (after 48 h) were similar to those determined by the peroxidase-antiperoxidase staining of inclusions. MIC determinations after 24 h were suitable for screening the activities of quinolones, but less so for measuring the susceptibility of C. trachomatis to macrolides and tetracyclines. MIC determination by EIA was rapid, appropriate for standardization, and less cumbersome than determination by quantification of inclusions.

rRNA gene restriction patterns of Haemophilus influenzae biogroup aegyptius strains associated with Brazilian purpuric fever

The rRNA gene restriction patterns of 92 isolates of Haemophilus influenzae biogroup aegyptius, associated with conjunctivitis or Brazilian purpuric fever in the State of São Paulo, Brazil, were studied with 16 + 23S rRNA from Escherichia coli as a probe. All strains were classified into 15 patterns. Isolates from Brazilian purpuric fever cases were seen only in patterns 3 (most frequently) and 4 (rarely), whereas isolates from conjunctivitis were found in all 15 patterns. The study demonstrated that rRNA from E. coli can serve as a probe for molecular epidemiology.

Biotypes, serotypes, and susceptibility to antibiotics of 60 Haemophilus influenzae strains from genitourinary tracts

Sixty strains of Haemophilus influenzae were isolated from the genitourinary tracts of adults: 19 from cervicovaginal secretions, one from a woman with bartholinitis, 37 from urethral exudates, and three from urine. Non-capsulated strains were recovered predominantly, and biotype III accounted for 28 isolates and biotype IV for 25. Many of the H influenzae strains were found to be resistant to one or more of the antibiotics commonly used against sexually transmitted diseases. Resistance to tetracycline was prevalent and was found in 17 of the strains. Ten strains were ampicillin resistant and beta lactamase producing. Kanamycin resistance was less common (two strains). Trospectomycin (U-63366), a new spectinomycin analogue, was eight to 16 times more active than spectinomycin. All the quinolones tested were very active against all strains and may provide an effective alternative for the treatment of resistant H influenzae in genitourinary infections.

Sexual behavior and smoking: risk factor for urethritis in men

Two hundred men who had symptoms of urethritis and 207 controls were interviewed. Because 60% of the men were of foreign nationality, the analysis of risk factors for urethritis was undertaken separately for the French and foreign subpopulations. The risk factors for urethritis were different for the French and foreign men. For the French men who had smoked, the risk of infection was 2.9 times greater than that for men who had never smoked (95% confidence interval, 1.2-7.6), after taking type of sexual behavior into account. There is a significant increase in the risk of urethritis when the amount of tobacco consumed daily increases (P less than 0.02). This finding suggests that smoking is an independent risk factor.

[Characteristics of penicillinase-producing strains of Neisseria gonorrhoeae isolated in France, 1979-1986]

Penicillinase producing Neisseria gonorrhoeae PPNG, had been first isolated in France in 1979. Since, they regularly increased if we considered France on the whole. From 1979 to 1986, 284 strains had been collected by a multicentric group. The frequency of isolation was strongly different in France, unknown in some region they rose 12% in specific areas in Paris. The PPNG strains were more frequently isolated from male than female (sex ratio was higher with PPNG than for non producing strain). They were more often responsible of complicated infections in female than male at the same rate than the non producing strains. Auxotype distribution was different between producing and non producing strains. Plasmidic content from african type (Af) was almost the same than from asian type (As). Strains with Af type associated with the conjugative plasmid were increasing.