In vitro activity of azithromycin against Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis in comparison with erythromycin, roxithromycin and minocycline

The in vitro activity of azithromycin against 40 strains of Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis was investigated in comparison with erythromycin, roxithromycin and minocycline. All C. trachomatis strains were inhibited by azithromycin at a concentration < or = 0.5 microgram/ml. The initial minimum inhibitory concentration (MIC) of the drug for U. urealyticum was 4 microgram/ml, whereas some resistance against the drug was shown by M. hominis. Erythromycin and roxithromycin presented almost comparable activities, whereas minocycline was slightly more active than macrolides against C. trachomatis (MIC < or = 0.25) and more active against M. hominis (initial MIC < or = 1 micrograms/ml). Only 97% of U. urealyticum strains were susceptible to 8 micrograms/ml of minocycline.

In-vitro activity of roxithromycin against Chlamydia trachomatis

Ten Chlamydia trachomatis isolates were tested for their sensitivity to roxithromycin, in comparison with erythromycin and tetracycline. The minimum inhibitory and minimum bactericidal concentrations of roxithromycin ranged from 0.03-0.12 and 0.25-1 microg/ml, respectively.

In-vitro activity of ofloxacin against Chlamydia trachomatis

The in-vitro activity of ofloxacin was evaluated against recently isolated Chlamydia trachomatis strains from patients suffering from non-gonococcal urethritis. The minimal inhibitory concentration (MIC) proved to be 1 mg/l against 8 of the 10 strains assayed (the MICs for the other two strains were 0.5 and 2 mg/l). The data obtained confirm that ofloxacin is active against Chlamydia trachomatis at concentrations achievable with the routine dosage regimen. The drug may thus be regarded as potentially useful for the treatment of non-gonococcal urethritis due to Chlamydia.

Enzyme-linked immunosorbent assay for the in-vitro detection of sensitivity of Chlamydia trachomatis to antimicrobial drugs

A new method of testing antimicrobial activity in vitro against Chlamydia trachomatis by enzyme-linked immunosorbent assay (ELISA) was developed by using a monoclonal antibody reacting with the major outer membrane protein of C. trachomatis LGV2 serotype. ELISA was compared with standard iodine stain, with immunofluorescence assay (IFA) and immunoperoxidase assay (IPA) performed with the same monoclonal antibody as in the ELISA. The MICs and MBCs of rifampicin, oxytetracycline, erythromycin, chloramphenicol and cefazolin detected by ELISA were higher than those determined by iodine stain and slightly lower than those determined by IFA and IPA. Since ELISA was at least as informative as the previously described techniques, but more rapid and standardizable and easier to perform, the assay may be useful in measuring the antimicrobial drug susceptibility of C. trachomatis.

Prevalence of enteric adenovirus from acute gastroenteritis: a five year study

Adenoviruses were detected in the stools in 459 of 3932 (11.6%) pediatric children hospitalized with acute gastroenteritis from January 1981 to December 1985. Out of the 459 adenovirus specimens 325 (8.3%) were presumptively identified as enteric adenovirus both by an adenovirus genus specific ELISA and by growth characteristics of adenovirus isolates in HEp-2 cells and in 293 cells. Enteral adenoviruses were found endemic since these viruses have been found for 5 successive years. A seasonal variation in the rates of adenovirus was also observed. Comparative data of rotavirus prevalence in the same study population are reported.

Class specific immunoglobulin response to individual polypeptides of Chlamydia trachomatis, elementary bodies, and reticulate bodies in patients with chlamydial infection

Sera from 10 women with Chlamydia trachomatis culture positive cervicitis and sera from six men with C trachomatis positive non-gonococcal urethritis were studied for the presence of IgG, IgM, and IgA antibodies to polypeptides of C trachomatis elementary bodies and reticulate bodies using immunoblotting techniques. All the sera with IgG, IgM, or IgA immunoglobulins specific to C trachomatis recognised the major outer membrane protein (MOMP) of elementary bodies. IgG antibodies also detected several other proteins, whereas IgM immunoglobulins recognised only MOMP and proteins of 60 kD, 62 kD, and 66 kD. The IgA reacted with MOMP and the 60 kD and 62 kD proteins in elementary bodies. Class specific antibody response against the proteins of reticulate bodies was similar to that observed for elementary body antigens--with one substantial difference: no reaction was observed in the 60 kD and 62 kD positions. This suggests that 60 kD and 62 kD proteins are deficient in reticulate bodies.

Antigenic specificity of serological response in Chlamydia trachomatis urethritis detected by immunoblotting

Sera from 19 patients with Chlamydia trachomatis culture positive non-gonococcal urethritis were studied for the presence of antibodies to chlamydial proteins by immunoblotting. Ten C trachomatis negative patients with non-gonococcal urethritis and 10 healthy controls were also studied. Acute phase sera from C trachomatis positive patients with non-gonococcal urethritis reacted only with the major outer membrane protein whereas all the convalescent phase serum samples reacted with the major outer membrane protein and with a 60,000 and a 62,000 molecular weight protein. Some sera also reacted with a 45,000 molecular weight protein. Five of 10 convalescent phase samples from patients with C trachomatis negative non-gonococcal urethritis showed a reaction pattern comparable with that observed in convalescent sera from C trachomatis from C trachomatis positive patients with non-gonococcal urethritis. Sera from healthy seronegative subjects were negative by blotting.

Evaluation of antibodies to Epstein-Barr virus in Italian patients with nasopharyngeal carcinoma

An association of Epstein-Barr virus (EBV) with nasopharyngeal carcinoma (NPC) has been established serologically in Italian patients. The finding of IgA antibodies to EBV-capsid antigen (VCA) and to early antigen (EA) showed a high degree of correlation for patients with NPC, thereby confirming previous reports. In addition, when considered together, IgA anti-VCA and IgG anti-EA antibody titres appeared to distinguish NPC-patients from those in control populations. Poorly differentiated and undifferentiated carcinomas with lymphoid cellular infiltrations showed the highest frequency of association with positive EBV serological tests.

A two-year longitudinal study on the etiology of acute diarrhea in young children in Northern Italy

During a 24-month period, 561 young children (6 months-2 years of age) hospitalized for acute diarrhea were studied for enteric pathogens. Patients positive for one or more pathogens were 359 (64.0%). Infection with one pathogen was found in 266 (47.4%) patients, whereas multiple infection was detected in 93 (16.6%) patients. Enteropathogens associated with disease were Rotaviruses: 150 (26.7%), Adenoviruses: 99 (17,6%), non-polio Enteroviruses: 48 (8.5%), Coronaviruses: 10 (1.8%), Parvoviruses: 5 (0.9%), Salmonella sp.: 41 (7.3%), Campylobacter fetus: 45 (8.0%), Giardia lamblia: 8 (1.4%), and "enteropathogenic" E. coli: 63 (11.2%) of which 15 (3%) produced heat labile enterotoxin. Seasonal occurrence of enteropathogens is also described.

In vitro activity of ciprofloxacin against Chlamydia trachomatis and Ureaplasma urealyticum

The in vitro activity of ciprofloxacin against 5 strains of Chlamydia trachomatis and 5 strains of Ureaplasma urealyticum was tested. Both C. trachomatis and U. urealyticum showed a certain degree of variability in their susceptibility to the drug. The minimum inhibitory concentration (MIC) of ciprofloxacin against C. trachomatis was 1 micrograms/ml, whereas the minimum bactericidal concentration was greater than or equal to 10 micrograms/ml. The MIC of ciprofloxacin against U. urealyticum was 1 micrograms/ml for 3 strains and higher than 10 micrograms/ml for two strains.

Serum specific IgA antibody to Chlamydia trachomatis in patients with chlamydial infections detected by ELISA and an immunofluorescence test

Sera obtained from 34 men with Chlamydia trachomatis positive non-gonococcal urethritis, 34 men with C trachomatis negative non-gonococcal urethritis, 42 women with acute salpingitis, 38 healthy women, and 34 healthy men were studied for the presence of specific serum C trachomatis IgA and IgG antibodies. Serological results were correlated with C trachomatis isolation in cell culture. An enzyme linked immunosorbent assay (ELISA) for C trachomatis specific serum IgA was employed using highly purified elementary bodies of C trachomatis serotype L2 grown in LLC-MK2 cells. Results obtained for C trachomatis IgA antibody by the ELISA test were compared with results obtained for the same sera by a single antigen immunofluorescence technique. A good correlation (r = 0.91) was found between two methods. Serum IgG antibody was also determined in the same sera by the immunofluorescence technique. Patients with C trachomatis positive non-gonococcal urethritis had a significantly (p less than 0.0005) higher prevalence (94.1%) of serum IgA antibody by ELISA compared with patients with C trachomatis negative non-gonococcal urethritis (20.5%) or healthy men (5.9%). Similarly, women with acute salpingitis had a significantly (p less than 0.005) higher prevalence of serum IgA antibody (45.2%) compared with healthy controls (5.2%). Comparable results were obtained for C trachomatis serum IgA antibody using the immunofluorescence technique. The prevalence of C trachomatis IgG antibody was significantly higher in patients with C trachomatis positive non-gonococcal urethritis (97.0%) compared with those with C trachomatis negative non-gonococcal urethritis (33.3%) and healthy controls (23.5%). The importance of using specific C trachomatis serum IgA in the identification of chlamydial infection is discussed.

An immunoperoxidase assay for the detection of specific IgA antibody in Epstein-Barr virus infections

A technique using indirect immunoperoxidase antibody was developed for the detection of specific serum IgA antibody to Epstein-Barr virus capsid antigen and early antigen. The IgA technique was compared with an immunofluorescence antibody method. Epstein-Barr virus IgA antibody against viral capsid antigen was detected in all nine patients with Epstein-Barr virus associated undifferentiated nasopharyngeal carcinoma, in 13 (72.2%) of 18 patients with infectious mononucleosis, in 21 (28.3%) of 74 patients with acute lymphoblastic leukaemia, and in six (20%) of 30 patients who had recently had kidney transplants. Epstein-Barr virus IgA antibody against viral capsid antigen was also detected in four (10%) of 40 healthy subjects, but it was not found in any of 20 cord blood samples. Epstein-Barr virus IgA antibody to early antigen was detected in six (66.6%) patients with nasopharyngeal carcinoma and in two (2.7%) patients with acute lymphoblastic leukaemia. The immunoperoxidase assay for Epstein-Barr virus specific IgA was simple, reliable, and rapid and correlated well (r = 0.94) with the immunofluorescence antibody technique.

A simple immunoperoxidase method for detecting enteric adenovirus and rotavirus in cell culture

A technique which includes the use of indirect immunoperoxidase antibody (IPA) has been developed for detecting enteric adenovirus and rotavirus antigens in cell cultures and has been compared with immunofluorescence antibody assay (IFA). The IPA technique was as sensitive as the IFA. The number of positive cells detected by both techniques in tissue cultures was the same; false positive results were not observed. The applicability of IPA in clinical virology is discussed.

Rapid immunoperoxidase assay for detection of respiratory syncytial virus in nasopharyngeal secretions

Samples of nasopharyngeal secretions obtained from 70 infants and young children with acute respiratory disease were examined for the presence of respiratory syncytial virus by immunoperoxidase assay (IPA). The IPA was compared with the immunofluorescence assay and with cell culture isolation. Respiratory syncytial virus antigen-positive cells were detected by both IPA and immunofluorescence assay in 28 specimens; 25 samples were positive in cell culture. The agreement between virus isolation and IPA and IFA was 89%. The applicability of IPA to rapid viral diagnosis of respiratory syncytial virus infection is discussed.

Evaluation of a new latex agglutination test for detecting human rotavirus in faeces

Four methods for detecting rotaviruses (latex agglutination, electron microscopy, immunofluorescence and ELISA) have been compared on 57 faecal samples from children with acute diarrhoea. Complete agreement among the four techniques was found in 38 samples. One sample was positive by ELISA and latex agglutination but negative by the other two. For all the other samples there was agreement among three of the techniques only. In a blocking ELISA test, samples positive by ELISA only, turned out to be falsely positive. Assuming true positive or negative for those samples for which at least three techniques were in agreement, electron microscopy, ELISA and latex agglutination were more sensitive (96 per cent) than immunofluorescence (84 per cent). Electron microscopy was the most specific (96.4 per cent), followed by immunofluorescence (92.9 per cent), ELISA (89.4 per cent) and latex agglutination (85.9 per cent).

Virological course of herpes zoster in otherwise normal hosts

The virological course of herpes zoster infection in 42 otherwise normal hosts was studied by virus isolation and antibody titration. Varicella-zoster virus (VZV) was isolated from vesicle fluid from all three patients examined on the first day of the vesicular eruption and from five out of six examined on the second day. The isolation rate fell to one out of six patients on the seventh day of illness and VZV was not isolated from patients at a later stage of the illness. IgG antibodies were detected by IFAMA and ELISA, in sera from all the patients by the end of the first week of illness; IgG antibody titres were highest during the second and the third weeks. IgM antibodies to VZV were detected in sera from six of the 42 patients with herpes zoster after fractionation by ion-exchange chromatography.

A rapid immunoperoxidase assay for the detection of specific IgG antibodies to Chlamydia trachomatis

A technique, using indirect immunoperoxidase antibody (IPA), was developed for the detection of IgG antibody to Chlamydia trachomatis. The IPA technique employs glass slides with air-dried and acetone-fixed C trachomatis infected cells, which can be stored at -70 degrees C and used for several months. Antibody titres detected by IPA were comparable to those detected by the indirect fluorescent antibody technique.

Cytological and histopathological abnormalities of the cervix in genital Chlamydia trachomatis infections

Since genital infection with Chlamydia trachomatis may be associated with cervical abnormalities 160 patients with grandular ectopia attending a gynaecological outpatient clinic were examined for antibodies against C trachomatis, the presence of C trachomatis infection, and cytological and histopathological abnormalities of the cervix.A significantly higher incidence of histological dysplasia was found in women with glandular ectopia who had antichlamydial antibodies than in those without.