High Incidence of Non-B and Recombinant HIV-1 Strains in Newly Diagnosed Patients in Galicia, Spain: Study of Genotypic Resistance

The objectives of this study are to describe the incidence of non-B and recombinant HIV-1 strains in newly diagnosed HIV-1 infections in Galicia, northwest of Spain, during a 2-year period (May 2000 to June 2002), and the frequency of resistance-associated mutations in reverse transcriptase (RT) and protease (PR) genes, analysing the polymorphisms more frequently detected in non-B and recombinant viruses. All newly diagnosed HIV-1-infected patients attending the nine public hospitals of the seven main cities of Galicia were included in this study. RT, PR and V3 regions from HIV-1 RNA plasma were amplified and sequenced, being the corrected sequences sent to the Stanford HIV RT and Protease Sequence Database. Nineteen of 85 patients (22.3%) were infected by non-B or recombinant viruses: three subtype C, two G, one F1, one Dpol/A1V3, five CRF02_AG, one CRF14_BG, five BGpol/BV3 and one UKpol/UV3 (U, unknown fragment). Eleven of these 19 patients (57.9%) were foreign individuals living in Galicia infected through heterosexual contact, and the other eight (42.1%) were Spanish intravenous drug users who had shared injection equipment. Five of 85 patients (5.9%), all infected with B subtype viruses, showed resistance-associated mutations in RT (M184V, M41L, L210W, T215Y/D and K219Q). In one patient (1.2%) infected with a subtype G strain, resistance-associated mutations in PR (K20I+M36I+M46I+V82I) were detected. In subtype B viruses resistance mutations in PR were not detected. Several polymorphisms in RT: D123S, Q174K, D177E, T200A, V245Q, and PR: I13V, K20I, M36I, R41K, H69K, L89M were detected more frequently in non-B and recombinants than in B strains ( P<0.01 to P<0.001). This study reports a high incidence (22.3%) of newly diagnosed patients infected by different non-B and recombinant HIV-1 strains, in a geographical area of Spain, showing also a high frequency of polymorphisms in RT and PR genes.

[Meningococcal infection caused by Neisseria meningitidis serogroup C]

BACKGROUND

In recent years an increase has been observed in the prevalence of meningococcal infection by Neisseria meningitidis serogroup C and in the appearance of strains with moderate resistance to penicillin.

PATIENTS AND METHODS

A microbiologic study of the cases of meningococcal infection of serogroup C treated from 1995 to 1996 in the health care area of Ferrol (La Coruña, Spain) was carried out.

RESULTS AND CONCLUSIONS

Twenty-nine cases were detected in 1995 and 28 in 1996. Meningococcal infection was observed in patients ranging from 8 months to 21 years of age (mean 5.7 years). Distribution by sex was homogeneous. Two patients died. According to the clinical presentation, 11 were sepsis (38%), 4 meningitis (14%) and 14 both processes (48%). In 4 LCR samples, the analytical study was normal with posterior positive culture results. The detection of bacterial antigen by latex agglutination in CSF only detected 32% of the cases. MIC study determined that 11 strains (38%) presented moderate resistance to penicillin, 9 with a MIC of 0.12 microgram/ml, one with a MIC of 0.25 microgram/ml and another with a MIC of 0.5 microgram/ml. In all the cases the strains were sensitive to cefotaxime (MIC < or = 0.06 microgram/ml) and rifampicin (MIC < or = 0.5 microgram/ml). All the strains belonged to serogroup C serotype 2b, serosubtype P1.2,5. During the study period 4 additional cases of meningococcal disease by serogroup B were observed.

[Listeria meningitis and HIV infection]

Although listeria monocytogenes is an opportunistic pathogen, infection by this bacteria is infrequent in AIDS patients. We were describe a case of L. monocytogenes meningitis in a patient infected by the human immunodeficiency virus (HIV). Literature is reviewed, and the pathogenesis of infection by this bacteria and its relation to AIDS is discussed.

Recovery of Campylobacter from human faeces stored at 4 degrees C

Six hundred and thirteen fresh diarrhoeal faeces were inoculated on Skirrow blood agar (SK), on Preston blood free agar (PBF), and in Campy-thioglycolate broth (CT). After 24 h of storage at 4 degrees C, specimens were again inoculated on SK and PBF, and in Campylobacter enrichment broth (CEB). CT tubes were placed overnight at 4 degrees C. Plates and CEB tubes were incubated at 43 degrees C in microaerophilic conditions. A total of 68 specimens was positive for campylobacter on direct plating. Sixty-four of them were also recovered after subculturing from CT, and only 51 from CEB. Delayed inoculation of plates after storage of samples at 4 degrees C yielded 57 isolates. The storage of faeces at 4 degrees C for 24 h significantly reduces the number of campylobacter isolates. When samples are not plated immediately we recommend inoculating a CT tube maintained at 4 degrees C overnight as a holding medium.

Rapid automated method for screening of enteric pathogens from stool specimens

A total of 800 colonies suggestive of Salmonella, Shigella, or Yersinia species isolated on stool differential agar media were inoculated onto both conventional biochemical test media (triple sugar iron agar, urea agar, and phenylalanine agar) and Entero Pathogen Screen cards of the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.). Based on the conventional tests, the AutoMicrobic system method yielded the following results: 587 true-negatives, 185 true-positives, 2 false-negatives, and 26 false-positives (sensitivity, 99%; specificity, 96%). Both true-positive and true-negative results were achieved considerably earlier than false results (P less than 0.001). The Entero Pathogen Screen card method is a fast, easy, and sensitive method for screening for Salmonella, Shigella, or Yersinia species. The impossibility of screening for oxidase-positive pathogens is a minor disadvantage of this method.

Enzyme-linked immunosorbent assay for diagnosis of brucellosis

The performance of an ELISA for detection of total antibodies to Brucella spp. was compared with that of the Rose Bengal, standard agglutination and Coombs test in the diagnosis of brucellosis. Sera tested were from 208 patients from whom Brucella melitensis had been isolated, 177 patients with significant results in at least two conventional tests, and 107 patients with fever from whom no Brucella spp. had been isolated and in whom all conventional tests were negative. ELISA was the most sensitive test (97%), showing greater specificity (96%) and good predictive positive and negative values (98% and 94% respectively). ELISA was the only positive test in 6% of patients in whom brucellosis had been confirmed by culture.

Evaluation of four enrichment media for isolation of Campylobacter jejuni

Diarrheal stool specimens were inoculated into the following media: alkaline peptone water (APW), Bruce-Zochowsky medium (BZ), Campylobacter enrichment broth (CEB), Campy-thio broth (CT), and Skirrow blood-agar (SK) plate. All media were incubated at 42 degrees C in microaerophilic conditions for 24 h. Afterwards, a new SK plate was inoculated from every liquid medium. Campylobacter jejuni was isolated from 43 of the 259 specimens when CT was used, from 45 when APW was used, from 46 when BZ was used, and from 46 when CEB was used; these totals include specimens that grew after enrichment only, on SK plates only, and both after enrichment and on SK plates. No significant differences were found between the isolates obtained with and without enrichment procedures.

Comparative efficacy of seven selective media for isolating Campylobacter jejuni

Diarrheal stools from 263 patients were inoculated on seven selective media: Butzler selective medium, Blaser medium, Skirrow blood agar, Preston campylobacter selective medium, Preston campylobacter blood-free medium, Butzler Virion medium, and modified Preston medium (with amphotericin B [2 mg/liter]). A similar number of Campylobacter jejuni strains were isolated from all the media studied; nevertheless, the presence of competing fecal flora (FF) made the detection of suspect colonies difficult. Preston campylobacter blood-free medium with cefoperazone yielded the greatest number of C. jejuni isolations, and contaminating FF grew in only 9% of the plates showing C. jejuni growth; all the other media allowed the abundant growth of other FF, regardless of whether C. jejuni was isolated from them or not.