Post-mortem changes in hair bundles of the guinea pig and human cochlea studied by high-resolution scanning microscopy

High-resolution scanning electron microscopic studies have been made on the guinea pig cochlea on material fixed from 15 min to 4 h post-mortem. Changes in the surface texture and cross-links of stereocilia were detected after only 15 min. Such changes included an increase in granularity of the surface membrane, thickening, stretching and fracturing of all types of cross-links accompanied by splaying apart and loss of rigidity of stereocilia. These changes were more pronounced in the basal turns of the cochlea and in general increased in severity and spread more apically with increasing times post-mortem. By 4 h, many hair bundles consisted of a fused amorphous mass in which individual stereocilia were not discernible. Remarkably at this time, some hair bundles appeared to have suffered little damage. These results will facilitate better discrimination between effects solely due to post-mortem necrotic changes and those due to specific actions of ototoxic drugs and other insults.

Resistance of mice to genital infection with Neisseria gonorrhoeae

Five strains of mice (C3H, CBA, BALB/c, TO and ICR) were inoculated intra-vaginally with Neisseria gonorrhoeae in an attempt to produce an animal model of gonorrhoea. Of a total of 68 mice inoculated, only three (4.4%) were culture-positive after 3 days. Histological examination of both the genital mucosa of inoculated animals, and the mucosa of genital tract organ cultures inoculated in vitro failed to show any evidence of gonococcal adherence or colonisation. Mice of these strains, therefore, appear resistant to gonococcal infection of the genital tract.

High-level vancomycin-resistant enterococci causing hospital infections

Nosocomial infection or colonization due to enterococci with high-level resistance to vancomycin (minimal inhibitory concentrations [MICs] between 64 and greater than 2000 mg/L) has occurred in 41 patients with renal disease. These vancomycin-resistant enterococci were cultured from many sources including blood. All but one strain contained one or more plasmids ranging in molecular weight from 1.0 to 40 Megadaltons (MDa). Vancomycin resistance was transferable by conjugation to a susceptible recipient strain of Enterococcus faecalis but this was not always associated with plasmid DNA. The emergence of transferable high-level vancomycin resistance in enterococci causing significant clinical infections is of particular importance since vancomycin is widely regarded as a reserve drug for the management of infections with multi-resistant Gram-positive organisms.

[Diagnosis and therapy of ulcus molle today. Case report and review of the literature]

Chancroid, an ulcerous disease of the genitalia caused by Haemophilus ducreyi, occurs rarely but regularly in Germany. Exact diagnosis is based on the clinical features and a direct smear, and in particular on cultivation of the organism, showing its unique macromorphological characteristics. The sensitivity of cultivation has increased due to the development of selective media for primary isolation. Resistance problems during the last decade meant that a change to new therapeutic strategies was unavoidable. The work presented here includes a case report and a review of the recent literature, it illustrates modern methods of diagnosis and treatment of Haemophilus ducreyi infections 100 years after the first description of the organism.

[The etiopathogenesis of ulcus molle: current status of knowledge--approaches to future research]

Chancroid is a sexually transmitted disease characterized by genital ulceration. Although the pathology of chancroid lesions has been well described, we still know relatively little about the mechanism by which the causative agent, the bacterium Haemophilus ducreyi, produces disease. It is hoped that a better understanding of both the pathogenicity of H. ducreyi and the pathogenesis of chancroid will provide a rational basis for the development of improved strategies for the control of this disease.

Plasmid content, serotypes, and antimicrobial susceptibility of Neisseria gonorrhoeae strains isolated in Munich in 1987-88

Eighty-four strains of Neisseria gonorrhoeae isolated in Munich between January 1987 and June 1988 were characterized in terms of their plasmid content, protein I serovar and susceptibility or resistance to four antimicrobial agents. Eighty two percent of the strains belonged to serogroup 1B, the three most prevalent serovars being 1B-1, 1B-2 and 1B-6. Among the serogroup 1A strains, 1A-2 was the commonest serovar. Fourteen strains (16.7%) lacked the 2.6 Md cryptic plasmid, although two of these strains contained the conjugative gonococcal plasmid. Although some degree of resistance to penicillin and tetracycline was noted, all the strains were sensitive to spectinomycin and cefotiam.

Fine needle aspiration cytology in the management ENT of patients

Aspirates were obtained from 142 masses in 120 patients who presented with palpable swellings in the head and neck region. 120 specimens (84.51 per cent) were adequate for diagnostic purposes and the remaining 22 (15.49 per cent) were unsatisfactory. Final diagnosis was based on resection histology in 87 cases and close clinical follow-up in 55 patients. The overall sensitivity and specificity including unsatisfactory aspirates was 81.37 per cent and 93 per cent respectively (if the technically inadequate specimens were deleted 98.81 per cent and 94.44 per cent). In comparison with the final diagnosis typing of malignant tumours was possible in 58.33 per cent. The correct diagnosis was made in 63.89 per cent of benign lesions.

Antibiotic susceptibilities and plasmid profiles of Haemophilus ducreyi isolates from southern Africa

Thirty-eight strains of Haemophilus ducreyi isolated in southern Africa were tested in vitro against 15 antimicrobial agents including those frequently used for the treatment of chancroid. In addition, newer compounds which possess characteristics consistent with their possible use as single-dose therapy for the disease were tested. All isolates were found to be resistant to penicillin as a result of beta-lactamase production. The majority of strains were also resistant to tetracycline, sulphamethoxazole and trimethoprim, but susceptible to co-trimoxazole, erythromycin, spectinomycin, ceftriaxone, ceftizoxime, cefodizime, ciprofloxacin, fleroxacin, rifampicin, rifabutin and FCE 22250. beta-Lactamase production appeared to be associated with the presence of low molecular weight plasmids (5.7 or 7 Md). Sulphonamide resistance appeared to be either chromosomally-mediated or due to the presence of a 4.9 Md plasmid. No evidence of plasmid-mediated tetracycline resistance was observed.

Lectin typing of Haemophilus ducreyi

The cell wall carbohydrates of 43 strains of Haemophilus ducreyi isolated in different parts of the world were subjected to lectin analysis using commercial panels containing 14 different plant lectins of known specificity. Preliminary evidence indicated both intrastrain and inter-strain variation in cell wall carbohydrate composition. In addition, it was possible to group strains from different geographical areas by lectin agglutination patterns. Lectin typing might thus become a useful marker system for epidemiological investigation of Haemophilus ducreyi infections.

Antigenic analysis of Haemophilus ducreyi by Western blotting

Twenty-one strains of Haemophilus ducreyi were analysed by Western blotting using two antisera produced in mice. Common antigens of molecular weights 58, 46, 41, 28, 22 and 16 kDa were detected in all the strains. The antigens were protein in nature, since they could not be detected in whole-cell lysates which had been treated with proteinase K. The H. ducreyi strains showed antigenic cross-reactivity with strains of H. influenzae and H. parainfluenzae, but showed minimal or no cross-reactivity with seven other species of bacteria.

In vitro activity of eight antimicrobial agents against non-penicillinase-producing gonococci isolated in Munich

The susceptibility of 119 strains of Neisseria gonorrhoeae isolated in Munich in 1986 to eight antibiotics was assessed. Although some degree of resistance to penicillin and tetracycline, as well as high minimum inhibitory concentrations (MIC) of spectinomycin, were observed, all the strains were sensitive to ciprofloxacin, enoxacin, fleroxacin, cefotaxime, and FCE 22250.

Plasmid content and protein I serovar of non-penicillinase-producing gonococci isolated in Munich

One hundred and twenty-four strains of non-penicillinase-producing gonococci isolated in Munich in 1986 were characterized in terms of their plasmid content and protein I serovar. Eighty-two per cent of the strains belonged to serogroup 1-B with over half belonging to either serovar 1B-2 or 1B-3. Half of the 22 serogroup 1A strains belonged to serovar 1A-2. Nineteen strains (15.3%) were found to lack the 2.6 Md cryptic plasmid although seven of these strains contained the 24.4 Md conjugative plasmid. Nine of the 105 strains which harboured the cryptic plasmid also contained the conjugative plasmid. The 19 strains which lacked the cryptic plasmid comprised 10 different serovars, indicating the heterogeneous nature of this group of organisms.

Managing change in laboratory services

With increasing demands on limited budgets DGMs and UGMs are now looking at laboratory services often with cost containment and reducing duplication in mind. The most popular solutions being considered are centralisation and/or rationalisation both of which appear to be based on a view of the service as a simple supply and demand system. This view is inadequate and insufficient as a basis for planning and implementing change such as rationalisation.

The effect of campylobacter lipopolysaccharide on fetal development in the mouse

Purified lipopolysaccharide (LPS) obtained from isolates of Campylobacter fetus ss. fetus and Campylobacter jejuni impaired fetal development when administered to mice on day 13 of pregnancy. Strikingly more fetal resorption was produced by C. jejuni LPS than by similar amounts of C. fetus ss. fetus LPS. Three of the four Campylobacter strains examined produced LPS that had no effect on maternal health, but LPS from one C. jejuni strain killed all of the mice to which it was administered.

Characterisation of penicillinase producing gonococci isolated in Munich, 1981-6

Twenty three penicillinase producing strains of Neisseria gonorrhoeae (PPNG) isolated in Munich from 1981 to 1986 were characterised in terms of their plasmid content, auxotypes, protein I serovars, and sensitivity to antibiotics. Sixteen strains (70%) harboured a 4.4 megadalton plasmid, with 13 of these strains also containing a 24.4 megadalton plasmid. Seven strains (30%) contained a 3.2 megadalton plasmid, with only one of them containing a 24.4 megadalton plasmid. Thirteen strains (57%) were prototrophic, eight (35%) required proline, one required arginine, and one required proline and arginine for growth. Serovar analysis showed that 16 strains (70%) belonged to the protein IB serogroup and comprised four serovars (IB-1, IB-5, IB-7, and IB-8). The seven strains belonging to the IA serogroup also comprised four serovars (IA-2, IA-4, IA-6, and IA-10). Although 18 different categories of plasmid, auxotype, and serovar were found in the 23 PPNG strains, there was a similarity between the auxotypes in terms of the range of serovars they comprised. Measurement of minimum inhibitory concentrations (MICs) of antibiotics for the strains showed that they were all susceptible in vitro to spectinomycin (MIC less than or equal to 32 mg/l), enoxacin (MIC less than or equal to 0.25 mg/l), cefotaxime, ciprofloxacin, and ceftriaxone (MICs less than or equal to 0.064 mg/l), whereas about half showed some resistance to tetracycline or cefotiam, or both.

Presence of two strains of Neisseria gonorrhoeae in both the cervix and pharynx of a patient with disseminated infection caused by a single strain

Neisseria gonorrhoeae was cultured from the cervix, pharynx and blood stream of an 18-year-old woman who had a disseminated gonococcal infection. Two different phenotypes of N. gonorrhoeae, distinguished on the basis of their protein I serovar, whole-cell protein profile, lectin-type and antibiotic susceptibility, were isolated from both the cervix and pharynx, whereas only one of these phenotypes was isolated from the blood. This finding stresses the importance of blood cultures as a prelude to determining appropriate antimicrobial therapy in cases of disseminated gonococcal infection.

Plasmid content, auxotype and protein-I serovar of gonococci isolated in the Gambia

Twenty-nine strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) and 30 non-penicillinase-producing strains, all isolated in the Gambia, were characterized in terms of their plasmid content, auxotype and protein-I serovar. Sixty-two per cent of the PPNG strains contained the 3.2 MDa penicillinase-coding plasmid, and 38% had the 4.4 MDa plasmid. All the PPNG strains contained the 2.6 MDa cryptic plasmid but lacked the 24.4 MDa conjugative plasmid. In contrast, 46.7% of the non-PPNG strains harboured only the cryptic plasmid while 16.7% contained both the cryptic and conjugative plasmids. Seventeen per cent of the non-PPNG strains contained the conjugative plasmid only and 20% lacked plasmids. The PPNG and non-PPNG strains also differed in terms of their protein-I serovar. Eighty-six per cent of the PPNG strains belonged to serogroup 1 A, whereas the majority (60%) of non-PPNG strains belonged to serogroup 1 B. There was no significant difference in the auxotypes of the PPNG and non-PPNG strains, with both groups consisting predominantly of prototrophic and proline-requiring strains, with a minority of strains requiring arginine. When the 59 strains were each characterized in terms of their combined plasmid profile, auxotype and serovar, 39 different combinations were noted, which indicates the heterogeneous nature of the gonococcal population found in the Gambia.

Pili on Gardnerella vaginalis studied by electronmicroscopy

Fourteen recently isolated strains and two laboratory strains of Gardnerella vaginalis were examined by electronmicroscopy for the presence of pili. All strains isolated recently from both men and women were heavily pilated. In contrast only a few pili were seen on organisms of the two laboratory strains, with many of the organisms having no pili. The importance of multiple subculture in this loss was supported by the observation that the degree of pilation of one freshly isolated strain decreased on repeated subculture. Other findings suggested that this was probably due to gradual loss of pili and not to selection of organisms that were non-pilate originally.

Resistance of Gardnerella vaginalis to bactericidal activity of human serum

To assess the sensitivity of Gardnerella vaginalis to the complement mediated bactericidal activity of serum, six laboratory strains were incubated with normal human serum and two strains freshly isolated from women with non-specific vaginitis (NSV) were each incubated with homologous patient serum. There was no significant difference between the number of organisms recovered from unheated or heat inactivated serum after incubation at 37 degrees C for one hour with any of the strains tested. A suspension of G vaginalis incubated at 37 degrees C for one hour in heat inactivated homologous mouse antiserum with unheated normal human serum as a source of complement did not show any less viability than the control mixture using heat inactivated human serum. In contrast, a serum resistant strain of Neisseria gonorrhoeae incubated in heat inactivated homologous mouse antiserum with unheated normal human serum showed noticeably less viability than the control. G vaginalis therefore seems to be resistant to the bactericidal activity of both normal and immune serum.

Loss of ciliary activity in organ cultures of rat trachea treated with lipo-oligosaccharide from Haemophilus influenzae

Organ culture of rat trachea was used as an experimental model to examine the ability of lipo-oligosaccharide from Haemophilus influenzae to damage respiratory tract mucosal tissue. Lipo-oligosaccharide from two strains of H. influenzae produced a significant decrease in the ciliary activity of tracheal rings observed over a 3-5 day period. No loss of ciliary activity was observed with the lipid-free moiety of the lipo-oligosaccharide.

Detection of a species-specific antigen of Gardnerella vaginalis by Western blot analysis

Western blot analysis was used to identify antigenic components of Gardnerella vaginalis. Polypeptides bound to nitrocellulose membranes were probed with murine antisera raised to two strains of G. vaginalis, and antibody-antigen complexes were detected with 125I-labelled antimouse immunoglobulin followed by autoradiography. Although there was inter-strain variation in immunogenic polypeptide profiles, all 23 strains of G. vaginalis examined contained a common antigen of molecular mass 41 kDa. This antigen was not found in any of six other bacterial genera.

Pathogenesis and immunology of chlamydial infections of the genital tract

In recent years there has been a steady increase in our understanding of the pathogenesis and immunobiology of lower genital tract infections caused by Chlamydia trachomatis. Much of this increase in knowledge has stemmed from two areas of research: clinical, pathologic, and immunologic observations of patients and the development and study of animal models. Research on patients has included the use of techniques such as histologic examination of biopsy specimens and measurement of levels of antibody and/or leukocyte responses to chlamydial antigens. The animal models that have been developed include experimental genital tract infections not only with C. trachomatis but also with appropriate Chlamydia psittaci organisms, such as the agent of guinea pig inclusion conjunctivitis. Continued investigation of the pathophysiologic and immunologic bases of chlamydial genital tract disease should lead to the rational development of potential control measures, such as vaccines or other forms of prophylaxis or therapy.

Test procedures for continuous-flow anaesthetic apparatus

Equipment management arrangements in hospitals, including safety and function testing, relating to continuous-flow anaesthetic apparatus have been found wanting following examination of a number of recent incidents. A problem exists with the complexity of the tests required and the number of necessary test instruments. In this article the required tests are examined, and a specially designed test set to make fuller testing a practical proposition for hospital staff and for manufacturers' service technicians is described.

Susceptibility of different serovars of Chlamydia trachomatis to inactivation by normal human serum

The ability of a panel of normal human serum samples to inactivate 12 strains of Chlamydia trachomatis, each of a different serovar, was investigated. A wide range of antichlamydial activity was observed, with survival rates of C trachomatis varying from less than 1% in some experiments to 100% in others. The strain specificity of the anti-chlamydial activity exhibited by individual serum samples was not, however, related to the antigenic cross reactivity between serovars demonstrable by microimmunofluorescence testing, which suggested that type specific antigens were not predominantly involved in the inactivation process.

Azlocillin levels in human tears and aqueous humor

We administered 4 g of azlocillin sodium intravenously to 24 patients scheduled to undergo elective intraocular surgery and collected specimens of serum, tears, and aqueous humor from zero to six hours after infusion for assay by high-pressure liquid chromatography. We found that azlocillin is distributed into tears and penetrates into the aqueous humor of human volunteers with noninflamed eyes after a single intravenous dose. Levels of 4.17 micrograms/ml and 4.44 micrograms/ml were achieved in tears and aqueous humor, respectively.

Gentamicin, tobramycin, amikacin, and netilmicin levels in tears following intravenous administration

Peak and trough tear and serum concentrations were determined in 27 human volunteers undergoing intravenous (IV) gentamicin sulfate, tobramycin sulfate, amikacin sulfate, and netilmicin sulfate therapy. Although effective serum concentrations were achieved, tear levels were subtherapeutic. The mean peak tear concentrations were 0.4 microgram/mL, 0.5 microgram/mL, 1.7 micrograms/mL, and 0.3 microgram/mL for gentamicin, tobramycin, amikacin, and netilmicin, respectively. These levels did not approach the minimum inhibitory concentrations for Pseudomonas and raise some concern regarding the risk-benefit ratio of IV antibiotics for bacterial keratitis.

Demonstration by electron microscopy of pili on Gardnerella vaginalis

Eight strains of Gardnerella vaginalis were examined by electron microscopy for the presence of pili. Narrow pili ranging from 3.0 to 7.5 nm in diameter were seen on bacteria from five of the strains studied.

Adherence of Staphylococcus aureus to rabbit corneal epithelial cells

A system for the in vitro study of adherence of Staphylococcus aureus to rabbit corneal epithelial cells has been developed. Bacteria isolated from normal eyes showed the same adherence capacity, on the average, as bacteria from infected eyes. Adherence was not inhibited by preincubation of bacteria with bovine serum albumin, D-mannose, or N-acetyglucosamine.

Piperacillin levels in human tears and aqueous humor

Thirty patients scheduled to undergo elective intraocular surgery were each given 4 g of piperacillin intravenously. Specimens of serum, tears, and aqueous humor were collected from zero to nine hours after infusion and assayed for piperacillin content by high pressure liquid chromatography. In noninflamed eyes piperacillin sodium distributed into tears and aqueous humor in concentrations exceeding the minimum inhibitory concentration required for many gram-positive and gram-negative organisms. Higher levels of piperacillin were anticipated in patients with inflamed eyes who possessed an altered blood-aqueous barrier, and in patients receiving serial doses of this agent.

Radiotherapy for jugulo-tympanic paragangliomas (glomus jugulare tumours)

Sixty patients with glomus jugulare tumour, seen at St. Bartholomew's Hospital, London, over forty years, have been reviewed. The term 'jugulo-tympanic paraganglioma' is suggested as a more accurate name for these tumours. The following simple classification is recommended: Group I tumours (tympanic paragangliomas) are those with or without VIIth nerve palsy, but with no other cranial nerve involvement. Group II tumours (jugular paragangliomas) are those with involvement of any cranial nerve other than the VIIth. The method and results of treatment by radiotherapy are discussed. It is concluded that surgery and radiotherapy give comparable results in Group I tumours, but radiotherapy gives superior results in Group II tumours.

A study of the susceptibility of three species of primate to vaginal colonization with Gardnerella vaginalis

In an attempt to develop an animal model of Gardnerella-associated vaginitis, several strains of Gardnerella vaginalis were inoculated into the lower genital tract of female pig-tailed macaques, tamarins and chimpanzees. G. vaginalis was not recovered from either tamarins or chimpanzees, but was recovered from each of 1O pig-tailed macaques inoculated with either of two freshly isolated Gardnerella strains, colonization persisting for 11-39 days. Examination of Gram-stained vaginal smears obtained from infected pig-tailed macaques failed to demonstrate clue cells, a feature which is pathognomonic of Gardnerella-associated vaginitis in humans. Other features characteristic of non-specific vaginitis, namely an increase in vaginal pH, and an increase in the ratio of succinate to lactate (S/L ratio) in vaginal fluid were not found. However, the physiology of the macaque vagina was found to be different from that of the human, the vaginal pH and S/L ratio of uninfected macaques both being higher than that seen in humans. The physiological differences between the macaque and human vagina may be due, in part, to a difference in their anaerobic vaginal flora. While these inter-species differences in vaginal physiology and microbiology limit the relevance of the pig-tailed macaque as a model of Gardnerella-associated vaginitis, the ease with which macaques are colonized with G. vaginalis may prove useful in studying bacterial adhesion and local immunity.

A colposcopic and histological study of experimental chlamydial cervicitis in marmosets

A total of 14 marmosets were inoculated intra-vaginally with Chlamydia trachomatis and the development of genital tract disease was assessed microbiologically, by colposcopic examination of the cervical and vaginal mucosa and by cytological and histological examination of biopsy and autopsy specimens. Eight animals had infections which persisted microbiologically for 2-5 weeks, and six animals, three of which had been inoculated on multiple occasions in a previous study, apparently eliminated their infection within 1 week of inoculation. Colposcopic examination showed that four of the eight infected animals developed acute cervicitis characterized by erythema, occasional slight oedema, and the presence of cloudy or purulent cervical mucus. The other four infected animals showed minimal signs of cervical inflammation. Three of the six animals which rapidly cleared their infections developed slight cervical inflammation characterized by erythema and cloudy cervical mucus during the fortnight after inoculation. Six control animals inoculated with medium displayed minimal cervical changes. The diagnosis of acute cervicitis in the infected animals was confirmed by examination of histological sections and cervical smears, which revealed the presence of polymorphonuclear leucocytes, with lymphocytes occasionally being seen. Although inflammatory changes were occasionally noted in specimens from control animals, the changes were relatively mild and occurred at a later time than those seen in infected animals. Intracytoplasmic chlamydial inclusions in epithelial cells were not detected in any of the specimens studied. Examination of genital tract tissue obtained at autopsy from five inoculated animals generally showed inflammation of the cervix and vagina, but in only one of these animals was there evidence of endometriosis and salpingitis.(ABSTRACT TRUNCATED AT 250 WORDS)

A study of inactivation of Chlamydia trachomatis by normal human serum

To assess the effect of human serum on the viability of Chlamydia trachomatis, organisms were mixed with unheated and heat inactivated homologous serum, and the numbers surviving after incubation at 37 degrees C for 1 hour were compared. With a pool of sera obtained from 12 donors, the number of chlamydiae surviving incubation in unheated serum was less than 1% of that surviving incubation in heat inactivated serum. The antichlamydial activity of the unheated pooled serum samples could be noticeably reduced by treatment with Mg-EGTA (ethyleneglycolbis (beta-amino ethyl ether)-N,N'-tetra-acetic acid). This indicated a requirement for calcium ions and showed that the alternative pathway of complement activation played only a minor role, if any, in the inactivation process. When 12 serum samples were tested individually it was found that four inactivated chlamydiae to an extent comparable with that seen with the pooled serum. The other eight samples showed only moderate (or slight) antichlamydial activity, with survival rates in unheated serum of 20-60% (or more than 60%) of those in heat inactivated serum. There was no correlation between the titres of antichlamydial antibodies and antichlamydial activity, all serum samples having undetectable or low concentrations of antibody on measurement by micro-immunofluorescence. The antichlamydial activity destroyed by heating was restored, however, when heat inactivated serum was mixed with an equal volume of an unheated serum that was not inhibitory to chlamydiae. When the latter serum was heated before addition antichlamydial activity was not restored, indicating the requirement of both a heat stable and a heat labile factor. This observation and the need for calcium ions for inactivation of chlamydiae are compatable with killing mediated by antibody and complement. Thus serum samples from individuals with no clinical or serological evidence of infection with chlamydiae vary in their ability to inactivate the organism, some having antichlamydial activity which is possibly mediated by antibody and complement.