Cultural method for large-scale screening for Chlamydia trachomatis genital infection.

Idoxuridine-treated McCoy cells grown as monolayers in 96 well microplates provide a convenient method for the isolation of Chlamydia trachomatis. Staining of infected monolayers with periodic acid-Schiff reagent (PAS) allows easy recognition of C trachomatis inclusions without the need for dark-ground microscopy. By this method 384 clinical specimens can be examined concurrently. It is sufficiently sensitive to form the basis of a chlamydial culture service for patients attending Sexually Transmitted Diseases (STD) Clinics.     

Multicenter evaluation of the AntigEnz Chlamydia enzyme immunoassay for diagnosis of Chlamydia trachomatis genital infection.

To evaluate the AntigEnz Chlamydia enzyme immunoassay (EIA) (Baxter/Bartels, Issaquah, Wash.), we studied 320 men and 1,209 women attending clinics for sexually transmitted diseases in Baltimore, San Francisco, and Seattle. At examination, two separate swabs were obtained from each patient, one for chlamydial culture and one for EIA. Cervical samples were collected from women, and urethral samples were collected from men. The prevalence of chlamydial infection by culture was 9% in Baltimore (n = 532), 11% in Seattle (n = 500), and 9% in San Francisco (n = 497). To resolve specimens with discrepant culture and EIA results, the EIA transport buffer was centrifuged and the resuspended pellet was stained by direct immunofluorescence to determine whether elementary bodies were present. Overall sensitivity of the AntigEnz Chlamydia assay compared with culture was 87% in men and 86% in women, and overall specificities were 94 and 97%, respectively. Differences between centers were seen, with sensitivities ranging from 76% among men and 79% among women in Seattle to 100% among men and 95% among women in Baltimore. With a true positive considered to be either a culture-positive or an EIA- and direct immunofluorescence-positive specimen, the revised sensitivity was 91% in men and 88% in women. Overall revised specificity was 99% in both men and women. We conclude that in this high-prevalence population, the sensitivity and specificity of this assay compare favorably with those of other noncultural antigen detection tests for the diagnosis of chlamydial genital infection.     

Experimental infection of the marmoset genital tract with Chlamydia trachomatis.

A strain of Chlamydia trachomatis isolated in McCoy cells from the urethra of a patient suffering from non-gonococcal urethritis was inoculated into the vagina of 8 female marmosets. Chlamydiae were isolated repeatedly for 10-42 days from the lower genital tract of 7 of the marmosets. Six of the infected animals developed an acute inflammatory reaction in the genital tract and chlamydial inclusions in epithelial cells were seen in smears from 2 of them. In addition, each of 6 infected marmosets examined developed humoral antibodies to C. trachomatis. In contrast, 3 control animals inoculated intravaginally with chlamydia-free McCoy cells showed no evidence of chlamydial infection. Since the marmoset is small and easily bred in captivity, it should provide a useful model for studying the mechanisms of chlamydial pathogenicity.     

Chlamydia trachomatis genital tract infection of antibody-deficient gene knockout mice.

The importance of antibody-mediated immunity in primary and secondary Chlamydia trachomatis genital tract infections was examined by using a definitive model of B-cell deficiency, the microMT/microMT gene knockout mouse. Vaginally infected B-cell-deficient microMT/microMT mice developed a self-limiting primary infection that was indistinguishable from infection of control C57BL/6 mice. Sera and vaginal secretions from infected mice were analyzed for anti-Chlamydia antibodies. C57BL/6 mice produced high-titered serum anti-Chlamydia immunoglobulin G2a (IgG2a), IgG2b, and IgA antibodies, and vaginal washes contained predominately anti-Chlamydia IgA. Serum and vaginal washes from infected B-cell-deficient mice were negative for anti-Chlamydia antibody. T-cell proliferation and delayed-type hypersensitivity assays were used as measures of Chlamydia-specific cell-mediated immunity and were found to be comparable for C57BL/6 and B-cell-deficient mice. Seventy days following primary infection, mice were rechallenged to assess acquired immunity. B-cell-deficient mice which lack anti-Chlamydia antibodies were more susceptible to reinfection than immunocompetent C57BL/6 mice. However, acquired immune resistance was evident in both strains of mice and characterized by decreased shedding of chlamydiae and an infection of shorter duration. Thus, this study demonstrates that cell-mediated immune responses alone were capable of resolving chlamydial infection; however, in the absence of specific antibody, mice were more susceptible to reinfection. Therefore, these data suggest that both humoral and cell-mediated immune responses were important mediators of immune protection in this model, though cell-mediated immune responses appear to play a more dominant role.     

Chlamydia trachomatis genital infections in tahiti

The rate ofChlamydia trachomatis infection was determined in three populations in Tahiti by means of a direct immunofluorescence test performed in specimens, tissue culture and detection of chlamydial antibody in serum specimens using a single-serotype indirect immunofluorescence test.Chlamydia trachomatis was recovered in 53 % of 53 bar girls, 24 % of 75 women attending a public maternity clinic for routine care, and 37 % of 71 men attending a sexually transmitted disease clinic with acute or subacute urethritis. The presence of chlamydial antibody in a high proportion of the groups studied confirmed the high frequency of chlamydial infections (62.3 %, 66.6 % and 83.1 % respectively).Neisseria gonorrhoeae infection was often associated with chlamydial infection in both bar girls and men with urethritis (11.4 % and 18.3 % respectively). With regard to clinical manifestations, 58.3 % (7/12) of bar girls and 23.2 % (10/43) women at the maternity clinic without clinical complaints were found to beChlamydia trachomatis-positive. The presence ofChlamydia trachomatis in these asymptomatic persons highlights their important role in spread of this organism in Tahiti. The findings indicate that routine testing forChlamydia trachomatis is warranted in patients attending the sexually transmitted disease and public maternity clinics in Tahiti.     

A model of genital Chlamydia trachomatis infection using human xenografts in severe combined immunodeficiency mice.

We developed a new model of human genital Chlamydia trachomatis infection in order to characterize the pathogen-host relationship in a clinically relevant system using a human strain of C. trachomatis instead of the commonly employed mouse biovar (MoPn). Human endometrial tissue was xenografted into the skin of mice homozygous for the mutation severe combined immunodeficiency and inoculated with C. trachomatis serovar K. C. trachomatis efficiently infected the endometrium as shown by cell culture and immunofluorescence microscopy and persisted for more than 6 weeks. Chlamydial inclusions detected by direct immunofluorescence and electron microscopy appeared to be smaller than those produced by in vitro cell culture-grown chlamydiae. A pattern of localized mild infection prevailed, and infiltrative uncontrolled spread of chlamydiae was observed in only 1 of 10 infected grafts. This might correspond to the well-known tendency of the agent to cause asymptomatic infections. This model allows the study of a human genital infection resembling the clinical situation and offers the possibility to better characterize the host-parasite relationship with respect to pathogenicity and therapy.     

Herpes simplex virus infection in guinea pigs: an animal model for studying latent and recurrent herpes simplex virus infection.

Footpad infection of guinea pigs with herpes simplex virus led to an acute local inflammatory reaction, followed by a persistent latent infection of lumbosacral dorsal root ganglia. Spontaneous reactivation of the latent virus occurred, leading to recurrent lesions at the site of the initial infection. Clinical observations and virological studies during the acute latent and recurrent infection are reported.     

A murine model for the study of Chlamydia trachomatis genital infections during pregnancy

Pregnant BALB/c mice were inoculated intravaginally on day 5 of gestation with the Chlamydia trachomatis mouse pneumonitis biovar. Animals that received 10(5), 10(6), or 10(7) inclusion-forming units (IFU) of C. trachomatis delivered prematurely on days 15 to 16 of gestation. A focal inflammatory infiltrate was observed in the wall of the uterus on the day 14 of gestation in animals inoculated with 10(5) IFU. In this group of mice, immunohistochemical analysis showed chlamydial inclusions in the endometrium and fetal membranes.     

Comparison of detection procedures for Chlamydia trachomatis, including enzyme immunoassays, in a mouse model of genital infection

Two chlamydial enzyme immunoassays, Chlamydiazyme and IDEIA, were evaluated in a mouse model of chlamydial genital-tract infection. The Chlamydiazyme assay and the IDEIA were assessed on specimens from 10 and 11 mice, respectively. The animals were infected with Chlamydia trachomatis, strain SA2f, and the results obtained by these methods on vaginal specimens taken on 4 or 5 occasions during 41-42 days were compared with those obtained in cell culture and to a less extent by the MicroTrak direct immunofluorescence test. In comparison with culture, the Chlamydiazyme assay had a sensitivity of 62% and a specificity of 92%; IDEIA had a sensitivity of 76% and a specificity of 94%. These assays sometimes did not detect chlamydiae in specimens taken immediately before specimens which proved positive by culture and the immunoassays were less sensitive if swabs were taken after those for culture. The IDEIA also failed to detect chlamydiae in the late stage of the murine infection when chlamydial elementary bodies were seen by immunofluorescence. The implications of the observations for investigations in the human field as well as for further studies in the mouse are discussed.     

Cellular immune response during uncomplicated genital infection with Chlamydia trachomatis in humans.

Extraction of staphylococcal abscesses by the Folch procedure revealed that all of the staphylocidal activity was present in the lipid fraction. Further separation of the lipids indicated that the bactericidal activity resided in the free fatty acid pool. Lipids similarly extracted from mesenteric or epididymal fat tissue, either before of after activation, did not possess comparable activity. Myristic, palmitic, palmitoleic, linoleic, and oleic acids, as well as lysolecithin, also failed to exhibit the properties of the fatty acid fraction obtained from abscess homogenates. These findings suggest the staphylocidal fatty acid is not a common host lipid.     

中国株庚型肝炎病毒(HGV)感染猕猴的实验研究

应用０．５ｍｌ含中国株庚型肝炎病毒（ＨＧＶ）的血清接种５只猕猴，５只猕猴于接种后１周血清ＨＧＶＲＮＡ均阳转；ＨＧＶＲＮＡ滴度在猴体内可高达１∶１０５，较接种血清中ＨＧＶＲＮＡ滴度（１∶１０２）高出许多，提示ＨＧＶ在猕猴体内复制。其中４只猕猴血清抗－ＨＧＶ阳转；４只出现ＡＬＴ异常。后用其中１只猕猴感染后４５天的血清给另２只猕猴接种，该２只猴也出现血清ＨＧＶＲＮＡ和抗－ＨＧＶ阳转及ＡＬＴ异常。本研究表明，中国猕猴有可能作为ＨＧＶ感染的动物模型。     

沙眼衣原体D型生殖道感染小鼠动物模型的建立及评价

目的 建立沙眼衣原体(Chlamydia trachomatis,Ct)D型感染小鼠生殖道动物模型,为研究人类生殖道Ct感染的病理变化和致病机制提供实验基础.方法 分离20个临床株,经阴道接种C3H/HeJ小鼠,得到清除时间明显延长的临床株(UT0603).应用该临床株建立Ct D型感染模型,免疫荧光检测阴道脱落上皮细胞中衣原体的含量;原位组织免疫荧光检测上生殖道的衣原体感染定植情况;分离生殖道组织,肉眼观察并进行病理学评分.结果 Ct 临床株感染小鼠下生殖道其排菌量及排菌周期明显延长,可见衣原体有上行感染和定植,并能引发类似人类生殖道感染的病理变化.结论 成功建立了Ct D型生殖道感染动物模型.     

B-cell-deficient mice develop complete immune protection against genital tract infection with Chlamydia trachomatis.

We evaluated the ability of mice made genetically deficient for B cells to resolve a primary infection and to develop protective immunity against vaginal challenge with a human isolate of Chlamydia trachomatis bacteria. The B-cell-deficient microMT mice cleared a primary ascending infection with similar or faster kinetics compared with wild-type mice. The presence of chlamydial inclusion bodies and the degree of inflammation in the upper genital tract was comparable and showed similar kinetics in microMT as in wild-type mice. Following resolution of the primary infection the mice were challenged by 100 ID50 of live bacteria and the level of protection and the extent of local inflammation was assessed. Strikingly, all microMT mice, as well as most of the wild-type mice, demonstrated complete immune protection with no bacterial shedding. While high titres of chlamydia-specific antibodies were stimulated locally and systemically in wild-type mice, no antibodies were detected in microMT mice. However, in both strains, immunohistochemical analysis of the upper genital tract demonstrated the presence of large numbers of CD4+ T cells and increased levels of interferon-gamma (IFN-gamma)-producing cells. The results unequivocally demonstrate that antibodies are not required for full protection to develop against ascending infection with a high dose of C. trachomatis in the female genital tract. Our study confirms the notion that cell-mediated immunity, in particular that owing to CD4+ T helper I (Th1)-type cells, is critical for host resistance against C. trachomatis in mice.     

Chlamydia trachomatis infection in pregnancy: risk factor for an adverse outcome

A cohort of 122 pregnant women attending the hospital antenatal clinic in northern India were studied to determine the prevalence of genital chlamydial infection, and any adverse effect on the pregnancy. Endocervical swabs were taken at > 12 weeks of pregnancy and cultured for Chlamydia trachomatis. Twenty-six (21.3%) pregnant women were found to be infected with C. trachomatis. The mean age, gravidity and parity were significantly higher (25.03 vs 23.6 years, 1.88 vs 1.72 and 0.92 vs 0.68 respectively [P < 0.005]) in women from whom C. trachomatis was isolated. Follow-up was possible in 87 women who delivered in the hospital. There was increased incidence of still-birth, prematurity and low birth-weight in the C. trachomatis-positive women (16.6% vs 5.7%, 26.6% vs 18.4% and 26.6% vs 23.0%), and these differences were statistically significant (P < 0.5, P < 0.5 and P < 0.05 respectively). The results suggest a definite need for C. trachomatis screening on a wider scale, both in different risk groups of asymptomatic antenatal women and in neonates, to confirm these findings.     

沙眼衣原体感染诱导精子凋亡

目的:研究精液沙眼衣原体(CT)感染对男性生殖的影响.方法:选择精液CT阳性的男性不育者57例作为CT阳性组,另选择正常对照组15例.检测精液常规,免疫层析法检测CT感染情况,末端脱氧核苷酸转移酶(TdT)介导的TUNEL法检测凋亡精子.结果: CT阳性组精子凋亡率为33.03%±14.98%,正常对照组为9.68%±2.78%,CT阳性组精子凋亡率明显增高.结论:精液CT感染诱导精子凋亡率增加,精液沙眼衣原体感染是引起男性不育的原因之一.     

Dissemination of Chlamydia trachomatis chronic genital tract infection in gamma interferon gene knockout mice.

Mice (C57BL/6), treated with progesterone and infected intravaginally with the mouse pneumonitis strain of Chlamydia trachomatis (MoPn), acquired genital tract disease that ascended from the endocervix to the uterine horns, oviducts, and ovaries in a temporal fashion before the occurrence of spontaneous microbiological resolution by about 28 days after infection. Surprisingly, dissemination of MoPn in small numbers to draining lymph nodes, the peritoneal cavity, spleen, liver, kidneys, and lungs occurred in normal mice during the early stages of disease (7 to 14 days) in a portion of infected animals but resolved from these tissues, by microbiological criteria, prior to resolution of genital tract involvement. In contrast, gamma interferon knockout (IFN-gamma KO) mice exhibited dissemination of infection to a greater extent and for longer periods in a variety of tissues, and a portion of infected IFN-gamma KO mice failed to microbiologically resolve their genital tract disease. By comparison, C57BL/6 SCID mice uniformly failed to resolve their genital tract disease and exhibited high levels of dissemination to all tissues tested for extended (50-day) periods of times. Interestingly, although IFN-gamma KO mice failed to completely clear organisms from their genital tracts, they exhibited an attenuated infection indistinguishable from that of heterozygous littermates when challenged 112 days after primary infection. These data support a role for IFN-gamma in containing dissemination of MoPn from the genital tract to extragenital sites and in the microbiological resolution of infection. Data also indicate that IFN-gamma is not required for modulating reinfections, which normally follow a shorter and less dramatic course.     

Variation in virulence among oculogenital serovars of Chlamydia trachomatis in experimental genital tract infection.

Seven different oculogenital serovars (D, E, F, G, H, I, and K) of Chlamydia trachomatis were inoculated intravaginally into CF-1 mice, and subsequent infection was monitored. The duration of infection was longest with serovars D and E. This may help to explain clinical surveys which demonstrate a high (50%) prevalence of these serovars. Furthermore, a comparison of the invasiveness of strains D and H demonstrated a much higher frequency of uterine horn infection with serovar D.