Eye Swab Samples Research Articles

Investigation of the presence of Chlamydia spp., Mycoplasma spp. and Moraxella ovis in infectious keratoconjunctivitis cases in sheep and goats in Siirt province and evaluation of clinical findings

Infectious keratoconjunctivitis is an infectious disease that negatively affects animal welfare causing systemic or local clinical signs in small ruminants and causes significant economic losses in herds. It is important to determine the etiologic agent causing the infection in the development of the protection and control strategies against the disease. The aim of this study was to determine the presence of infectious keratoconjunctivitis cases in small ruminants raised in Siirt province in Türkiye. Infectious keratoconjunctivitis was graded according to the symptoms determined by clinical examination. The presence of Chlamydia spp., Mycoplasma spp. and Moraxella ovis was investigated by PCR in swab samples obtained from the animals with keratoconjunctivitis. Infectious keratoconjunctivitis was detected in 263 (19.86%) of 1324 animals examined in the study. Of the animals with infectious keratoconjunctivitis, 163 (61.97%) were sheep and 100 (38.02%) were goats. The detection rate of infectious keratoconjunctivitis was higher in sheep than goats. In 56 (21.29%), 109 (41.44%), 67 (25.47%), and 31 (11.78%) of the cases, findings of stage 1, 2, 3, and 4 infectious keratoconjunctivitis were detected, respectively. Of the eye swab samples taken from 263 animals with infectious keratoconjunctivitis, 5 (1.90%) were positive for Mycoplasma spp. and 6 (2.28%) were positive for M. ovis. It was determined that the distribution of the bacterial agents varied according to the stage of infectious keratoconjunctivitis. No statistically significant correlation was found in the distribution of bacterial agents among identified samples according to species, sex, age, and infectious keratoconjunctivitis stage of the animals. It was thought that the data obtained in the study would contribute to the studies for protection and control by determining the incidence and aetiology of infectious keratoconjunctivitis cases observed in small ruminants.

Emerging Bacterial Eye Infection: Identification, Susceptibility and Immunotherapy of Kocuria Species in Patients of Basrah, Iraq

Ocular infections are common and considered sight-threatening consequences Non-pathogenic commensal bacteria can cause a serious opportunistic pathogen among immunocompetent and immunocompromised individuals leading to blindness. The aim of this study was the identification bacteria isolated from ocular infections, investigate the antibiotic susceptibility, and using interleukin 17 (IL-17) as the immunotherapeutic agent to support the patient immune system. 33 eye swab samples were collected from people with microbial eye infections including (conjunctivitis, dacrocystis, corneal ulcers, and post-traumatic). Recovered isolates were gram stained and tested for antibiotic susceptibility. Out of 36 swabs, 14 bacterial isolates were identified. Gram positive bacteria were predominant isolates, pathogenic Staphylococcus species 6 (42.85%) followed by non-pathogenic commensal bacteria Kocuria spp. 5 (35.71%). Gram negative bacteria including only Moraxella species 2 (14.28%). Antibiotic susceptibility testing indicated high sensitivity of recovered isolates to tetracycline and Ofloxacin and significant resistance to both benzylpenicillin and erythromycin. The recovered bacteria exhibited significant resistance to IL-17 via Immunotherapeutic assay in-vitro. In conclusion, non- pathogenic commensal bacteria Kocuria spp. seems to be predominant and IL-17 lack to antimicrobial activity in-vitro.

Detecting Leishmania in dogs: A hierarchical-modeling approach to investigate the performance of parasitological and qPCR-based diagnostic procedures.

Domestic dogs are primary reservoir hosts of Leishmania infantum, the agent of visceral leishmaniasis. Detecting dog infections is central to epidemiological inference, disease prevention, and veterinary practice. Error-free diagnostic procedures, however, are lacking, and the performance of those available is difficult to measure in the absence of fail-safe "reference standards". Here, we illustrate how a hierarchical-modeling approach can be used to formally account for false-negative and false-positive results when investigating the process of Leishmania detection in dogs. We studied 294 field-sampled dogs of unknown infection status from a Leishmania-endemic region. We ran 350 parasitological tests (bone-marrow microscopy and culture) and 1,016 qPCR assays (blood, bone-marrow, and eye-swab samples with amplifiable DNA). Using replicate test results and site-occupancy models, we estimated (a) clinical sensitivity for each diagnostic procedure and (b) clinical specificity for qPCRs; parasitological tests were assumed 100% specific. Initial modeling revealed qPCR specificity < 94%; we tracked the source of this unexpected result to some qPCR plates having subtle signs of possible contamination. Using multi-model inference, we formally accounted for suspected plate contamination and estimated qPCR sensitivity at 49-53% across sample types and dog clinical conditions; qPCR specificity was high (95-96%), but fell to 81-82% for assays run in plates with suspected contamination. The sensitivity of parasitological procedures was low (~12-13%), but increased to ~33% (with substantial uncertainty) for bone-marrow culture in seriously-diseased dogs. Leishmania-infection frequency estimates (~49-50% across clinical conditions) were lower than observed (~60%). We provide statistical estimates of key performance parameters for five diagnostic procedures used to detect Leishmania in dogs. Low clinical sensitivies likely reflect the absence of Leishmania parasites/DNA in perhaps ~50-70% of samples drawn from infected dogs. Although qPCR performance was similar across sample types, non-invasive eye-swabs were overall less likely to contain amplifiable DNA. Finally, modeling was instrumental to discovering (and formally accounting for) possible qPCR-plate contamination; even with stringent negative/blank-control scoring, ~4-5% of positive qPCRs were most likely false-positives. This work shows, in sum, how hierarchical site-occupancy models can sharpen our understanding of the problem of diagnosing host infections with hard-to-detect pathogens including Leishmania.

Associated factors of the co-occurrence of trachoma and soil-transmitted helminthiases in children 1 to 9 years old in rural communities of the Amazon basin in Loreto Department, Peru: Results from a population-based survey.

BackgroundThere is evidence of the occurrence of trachoma in Peru, and studies have shown that soil-transmitted helminthiases (STH) are affecting rural communities in the Amazon basin in Loreto Department. This study was done to estimate trachoma prevalence, STH prevalence, and the associated factors for both diseases in children aged 1–9 years in rural communities of Peru.MethodologyA population-based cross-sectional survey was carried out in rural communities of Loreto. A standardized survey questionnaire with individual and household risk factors related to both diseases was used. Ocular examination was done for all participants aged one year and above, and eye swab samples were collected from children with follicular trachoma (TF). Anthropometric measurements, stool samples for STH, and blood samples for hemoglobin measurement were taken from children.Principal findingsTF prevalence was 7.74% (95% CI 5.08–11.63%), STH prevalence was 49.49% (95% CI 25.00–52.43%), and prevalence of co-occurrence of both diseases was 5.06% (95% CI 2.80–8.98%) in children aged 1–9 years. Being at age 3–8 years old (AOR = 6.76; 95% CI 1.346–33.947), have an unclean face (AOR = 24.64; 95% CI 6.787–89.444), and having been dewormed in the last six months (AOR = 2.47; 95% CI 1.106–5.514), were risk factors of TF. Being a female (AOR = 0.22; 95% CI 0.103–0.457) was associated with decreased odds of TF. Having been dewormed in the last six months (AOR = 0.30; 95% CI 0.139–0.628) was a preventative factor for STH. Risk factors for children with both diseases mirrored the findings for risk factors for individual diseases.ConclusionsNeglected tropical diseases and associated risk factors overlap in communities living in vulnerable conditions in the Amazon basin of Peru. These findings support the need to implement integrated interventions, including mass drug administration, water, sanitation, and hygiene for both diseases in the study area.

Analysis of Adenovirus Conjunctivitis Outbreak in a Neonatal Intensive Care Unit

Objective In this study, it is aimed to present the outbreak analysis of Adenovirus conjunctivitis (AC) that develops associated with medical devices used during retinopathy of prematurity (ROP) examination for retinopathy of prematurity. Materials and Methods In this study; The neonatal AK outbreak that occurred at the Sakarya Training and Research Hospital was retrospectively analyzed. Patient data were obtained from files and infection surveillance records. Bacteriological culture and polymerase chain reaction (PCR) examinations for Adenovirus were performed from the eye swab samples of the patients and ten medical instruments (blepharosta, indirect ophthalmoscope, scleral depressor and 20-28 diopters) used during ROP examination. Results After AK was detected in the eyes of a nurse working in a neonatal intensive care unit (NICU), one inpatient baby and three more babies developed AK. All four babies who developed AK had ROP examination on the same day. It was understood that eye examinations could not be performed with sterile or disposable instruments, disinfection was performed with 10% povidone iodine while passing from one baby's examination to another, and then it was used again in ROP examination. No pathogenic bacteria were grown in the bacteriological culture of eye swab samples. Adenovirus DNA was detected by PCR in eye swab samples of four newborns and nurses and in four devices called blepharosta used for ROP examination. Conclusion AC outbreaks develop in infants hospitalized in the NICU when standard precautions are not followed. Disinfection processes should always be carried out with standardized practices, standards should not be compromised and these practices should be constantly monitored.

Prevalence and Clinical Features of Ocular Adenoviral Infection among Patients Attended to Ibn-Alhaitham Teaching Eye Hospital in Baghdad, Iraq: A Molecular Study

Background: Viral conjunctivitis is commonly caused by adenoviruses, with a rate of up to 40% of all viralcauses.Objective: To show prevalence and clinical features of ocular adenoviral infection at Ibn-Alhaitham teachingeye hospital in Baghdad, Iraq.Patients and Method: In this cross-sectional study, eye swab samples were taken from 638 patients withclinically diagnosed infectious conjunctivitis during the period from August 2019 to February 2020. Sampleswere processed and tested using polymerase chain reaction (PCR) to detect adenoviral infection.Results: Of 638 patients with infectious conjunctivitis attended to the Ibn Al-Haitham teaching ophthalmichospital in Baghdad, 113 cases (17.7%) were confirmed to having ocular adenoviral infection with the meanage 27±8.4 years and The highest percentage of those affected in the age group 1-10-year-old (31.9%).Sixty-three were male (55.8%) and 50 were females (44.2%). non-statistically significant difference betweenunilateral &amp; bilateral involvement. Of total 113 patients with ocular adenoviral infection, 50 (44.2%)patients experienced flu-like illness during or before their ocular complaint, 85 (75.2%), 28 (24.8%) showedconjunctival follicular reaction and conjunctival membrane formation respectively. Only four (3.5%)patients showed no corneal changes during their ocular infection, 39 (34.5%) patients showed mild punctateepithelial keratitis, 54 (47.8%) patients showed significant punctate epithelial keratitis and 16 (14.2 %)patients showed anterior stromal infiltrate. 64 (56.6%) patients developed lymphadenopathy.During follow up, 13 (11.5%) of patients fully recovered within less than 14 days, 69 (61%) patientsrecovered in 2-4 weeks whereas 31 (27.4%) patients took longer than 4 weeks for a full recovery.Conclusion: Results have demonstrated that adenoviruses are common causative agents for infectiousconjunctivitis. PCR revealed to be more sensitive and accurate for detecting adenoviral ocular infection

Molecular typing of conjunctivitis-causing adenoviruses in Hanoi, Vietnam from 2017 to 2019 and complete genome analysis of the most prevalent type (HAdV-8).

Adenoviral conjunctivitis is a common epidemic worldwide. In Vietnam, up to 80,000 patients are infected with adenoviral conjunctivitis annually. However, there are few investigations on the pathogenic adenoviruses that cause conjunctivitis. In total, 120 eye-swab samples were collected from patients with viral conjunctivitis symptoms in Hanoi, Vietnam from 2017 to 2019. Human adenoviruse (HAdV) was detected in 67 samples (55.83%) using polymerase chain reaction amplification of at least one of three HAdV-specific marker genes (hexon, penton, and fiber). Of the 67 HAdV samples, 46 samples could be analyzed by all three marker genes. DNA sequence analysis and phylogenetic tree building based on the three marker genes from the 46 HAdV samples revealed five different HAdV types associated with conjunctivitis in Hanoi, including HAdV-3 (4.3%), HAdV-4 (2.2%), HAdV-8 (89.1%), HAdV-37 (2.2%), and a potential recombinant type between types HAdV-8 and HAdV-3 (2.2%). This showed that HAdV-8 was the most common type identified in Hanoi. Complete genome analysis of HAdV-8 isolated from a Vietnamese patient (VN2017) using Sanger sequencing revealed 34 unique nucleotide changes, indicating that the adenovirus continuously accumulates new mutations. Hence, continuous surveillance of HAdV-8 changes in Vietnam is necessary in the future.

Mycoplasma conjunctivae-Associated Keratoconjunctivitis in Norwegian Muskox (Ovibos moschatus).

In late summer 2014, an outbreak of ocular disease occurred in the Norwegian muskox (Ovibos moschatus) population. Animals showed rings of pus around their eyes and one euthanized animal was diagnosed with acute keratoconjunctivitis. The DNA sequence analysis of eye-swab samples from this animal revealed a high abundance of Mycoplasma conjunctivae.

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infections among pregnant women and eye colonization of their neonates at birth time, Shiraz, Southern Iran

BackgroundChlamydia trachomatis and Neisseria gonorrhoeae are the two common transmissible pathogens from pregnant women to their neonates. Given the lack of routine screening and treatment of pregnant women in some areas, the possibility of transmission rises. This study seeks to determine the prevalence of C. trachomatis and N. gonorrhoeae in the pregnant women with no clinical symptoms and the vertical transmission rate to their neonates.MethodsThe study was conducted on endocervical and eye swab samples of 239 pregnant women and their neonates. Identification was based on PCR method.ResultsThe prevalence rates of C.trachomatis in women and neonates were 37/239 (15.5%) and 28/239 (11.7%), and for N. gonorrhoeae 3/239 (1.3%), 1/239 (0.4%), respectively. The vertical transmission rates to the neonates were 28/37(75.6%) for C. trachomatis and 1/3 for N. gonorrhoeae.ConclusionsIn the areas with a high prevalence of chlamydial or gonococcal infections, and in the absence of screening and treatment of the pregnant women, ocular prophylaxis with antibiotics is suggested as a part of routine neonatal care program for the prevention of chlamydial and gonococcal ophthalmia.

Detection and Isolation of Mycoplasma capricolum Subspecies Capricolum from East Azerbaijan Sheep Flocks.

Mycoplasma capricolum subspecies capricolum (Mcc) is one of the causative agents of contagious agalactia (CA), which is an important disease in sheep and goats in the Mediterranean and Middle East countries. Mycoplasma agalactiae is the classic agent of CA in sheep and goats. Mycoplasma mycoides subspecies Capri (Mmc), Mycoplasma capricolum subspecies capricolum (Mcc), and Mycoplasma putrefaciens (Mp) produce a clinically similar disease, more often in goats. The aim of the present study was to detect Mcc in sheep flocks in East Azerbaijan Province of Iran. Milk, ear canal, and eye swab samples were collected from 49 sheep flocks with clinical signs of CA or a history of a disease. All the samples were examined using both culture and molecular methods. In the molecular method,positive samples for the Mycoplasma genus were tested for M. mycoides cluster and Mcc. From 272 samples, 67, 87, and 62 samples were shown to be positive using the culture method, polymerase chain reaction (PCR) method, and both culture and PCR methods, respectively. Mcc was detected in all the four M. mycoides cluster positive samples, including milk, ear canal, and eye swab samples. This is the first report of Mcc detection from East Azerbaijan. Our results showed that eye, milk, and ear canal samples could be suitable sources for Mcc detection in sheep flocks.

Conjunctivitis due to Neisseria sicca: A case report

We report the first case, in Medline-based literature, of conjunctivitis caused by gram negative diplococcus, Neisseria sicca. Although it is not widely accepted as such, isolation from cultures of repeated eye swab samples suggests that N. sicca may be a pathogen in conjunctival infections. Positive culture for this organism should not be readily dismissed. Such conjunctivitis responded favorably to treatment with netilmicin eye drops.

Identification and Characterization of Two Novel Viruses in Ocular Infections in Reindeer

A thorough understanding of virus diversity in wildlife provides epidemiological baseline information about pathogens. In this study, eye swab samples were obtained from semi-domesticated reindeer ( Rangifer tarandus tarandus) in Norway during an outbreak of infectious eye disease, possibly a very early stage of infectious keratoconjunctivitis (IKC). Large scale molecular virus screening, based on host nucleic acid depletion, sequence-independent amplification and next-generation sequencing of partially purified viral nucleic acid, revealed the presence of a new papillomavirus in 2 out of 8 eye swab samples and a new betaherpesvirus in 3 out of 8 eye swab samples collected from animals with clinical signs and not in similar samples in 9 animals without clinical signs. Whether either virus was responsible for causing the clinical signs or in any respect was associated to the disease condition remains to be determined.

Extrachromosomal DNA length and antibiograms of Staphylococcus aureus and Pseudomonas aeruginosa isolated from tears of HIV/AIDS patients after curing with sodium dodecyl sulphate.

Staphylococcus aureus and Pseudomonas aeruginosa strains were isolated from eye swab samples randomly obtained from 100 seropositive HIV/AIDS patients who reported to various anti-retroviral treatment clinics at the University of Benin Teaching Hospital and Central Hospital both based in Benin City, Nigeria. Invitro antibiotic sensitivity patterns of strains before curing were determined by the Kirby-Bauer disc diffusion technique. Resistance plasmid DNA of multidrug resistant strains was cured with 0.1% sodium dodecyl sulphate and cured strains were again subjected to invitro antibiotic sensitivity testing. EcoRI and Hind III restriction endonuclease enzymes were used to make cuts on extracted plasmid DNA whose length sizes were then determined. A total of 36 (36.0%) strains made up of 27 (75.0%) Staphylococcus. aureus and 9 (25.0%) Pseudomonas aeruginosa were isolated of which 7 (19.4%) strains showed multidrug resistance to ciprofloxacin, pefloxacin, ofloxacine, gentamycin, tetracycline, ampicillin, chloramphenicol, nitrofurantoin and erythromycin. All seven multidrug resistant strains before curing, recorded 85.7%, 42.9%, 14.3% and 14.3% sensitivity in that decreasing order to ciprofloxacin, pefloxacin, ofloxacin and gentamycin respectively. There was 0.0% sensitivity each to tetracycline and ampicillin. After curing, there was enhanced sensitivity of 100.0%, 85.7%, 28.6% and 71.4% respectively. There was also 28.6% and 57.1% improved sensitivity to tetracycline and ampicillin after curing. Before curing, there was 76.2% average resistance to all used antibiotics and this reduced to 47.6% after curing Staph. aureus plasmid DNA. In the case of Pseudomonas aeruginosa, there was an average resistance of 76.3% before curing which fell to 42.5% after curing. EcoRI restriction enzyme gave the plasmid DNA length of Staphylococcus aureus strain 04 as 4.0Kb and this size depended upon the distance between recognition sites. Isolation of 36 (36.0%) strains of both isolates from 100 eye swabs shows the danger these organisms portend to all categories of opticians. The cheapness and high sensitivity of gentamycin justifies its use as eye drops for treatment of some eye infections. Curing of plasmid DNA is an indication that if SDS is administered to the organisms in sublethal doses, it can lead to the elimination of plasmid DNA without adverse effect on the genomic DNA of the bacterial strains.

Cervid Herpesvirus 2, the Primary Agent in an Outbreak of Infectious Keratoconjunctivitis in Semidomesticated Reindeer

An outbreak of infectious keratoconjunctivitis (IKC) occurred in semidomesticated reindeer (Rangifer tarandus tarandus) in Troms County, Norway, in February 2009. Twenty-eight animals with clinical symptoms and 12 apparently healthy animals were investigated. They ranged in age from calves of the year to 4-year-old animals (mean, 1.9 years; standard deviation, +/-0.9). The seroprevalence of antibodies against cervid herpesvirus 2 (CvHV2) was 86% in animals with IKC and 42% in unaffected animals. For the 28 clinically affected animals, CvHV2 was detected by PCR in swabs obtained from the eye (82%), nose (64%), and vagina (24%), and CvHV2 was isolated from eye swabs from 8 animals. Virus was not isolated from clinically unaffected animals but was detected by PCR in eye swab samples from five of them. The viral activity, assessed by the ability to cause a cytopathic effect in cell culture, increased with the severity of clinical symptoms, but in severe clinical cases, virus was absent and secondary bacterial infections were dominant. Moraxella sp. isolates were obtained from seven animals, and those from two animals were identified as Moraxella bovoculi. Staphylococcus aureus, Streptococcus sp., and Arcanobacterium pyogenes were also isolated. It is concluded that CvHV2, which is endemic in reindeer, can cause IKC, probably most commonly as a primary infection of calves. This can be a very painful and devastating disease of economic importance for reindeer herders. This is the first report of CvHV2 as the primary agent of IKC in reindeer. This is also the first isolation of this virus in reindeer under natural herding conditions.

Characterization of Chlamydia trachomatis omp1 genotypes detected in eye swab samples from remote Australian communities.

Chlamydia trachomatis conjunctival samples collected over a 6-month period from individuals with clinical signs of trachoma and located in remote communities in the Australian Northern Territory were differentially characterized according to serovar and variants. The rationale was to gain an understanding of the epidemiology of an apparent increased prevalence of acute trachoma in areas thought to be less conducive to this disease. Characterization was performed through sequencing of a region of the omp1 gene spanning the four variable domains and encoding the major outer membrane protein. Nucleotide and deduced amino acid sequences were genotyped by using a BLAST similarity search and were examined by phylogenetic analyses to illustrate evolutionary relationships between the clinical and GenBank reference strains. The predominant genotype identified corresponded to that of serovar C (87.1%), followed by the genotype corresponding to serovar Ba (12.9%). All nucleotide and amino acid sequences exhibited minor levels of variation with respect to GenBank reference sequences. The omp1 nucleotide sequences of the clinical samples best aligned with those of the conjunctival C. trachomatis reference strains C/TW-3/OT and Ba/Apache-2. All clinical samples (of serovar C) exhibited four or five nucleotide changes compared with C/TW-3/OT, while all serovar Ba samples had one or two nucleotide differences from Ba/Apache-2. Phylogenetic analyses revealed close relationships between these Northern Territory chlamydial samples and the respective reference strains, although the high proportion of sequence variants suggests an evolutionarily distinct C. trachomatis population causing eye infections in Australia. Given that such genotypic information has gone unreported, these findings provide knowledge and a foundation for trachoma-associated C. trachomatis variants circulating in the Northern Territory.

Genetic diversity of Chlamydia trachomatis and the prevalence of trachoma.

Considerable variation in the outer membrane protein (ompA) of Chlamydia trachomatis has been uncovered by immunotyping and, more recently, by genotyping. This diversity may assist Chlamydia in evading the human immune system; organisms may have a competitive advantage if they infect a host who has previously been infected only by other strains. If so, a diverse set of strains may attain a higher prevalence in a community than a single strain. We determined the predominant strains of ocular C. trachomatis in trachoma-endemic villages of Nepal and tested the hypothesis that strain diversity is associated with the prevalence of infection. Major outer membrane protein gene sequences of chlamydial isolates were determined from ligase chain reaction-positive eye swab samples collected from 10 villages. The diversity of genovars was determined for each village, using Simpson's index. Two genovar families (Ba and C) and nine genovars were detected, with a single genovar (C1) comprising more than one-half of the samples. The prevalence of clinically active trachoma was significantly associated with the genetic diversity in a village, controlling for village size and number of samples taken in a village. Genetic diversity of C. trachomatis is associated with the prevalence of infection in a community, consistent with the hypothesis that diversity may be necessary to attain a high prevalence in a community.

Detection and identification of Mycoplasma conjunctivae in infectious keratoconjunctivitis by PCR based on the 16S rRNA gene.

A specific PCR assay based on unique sequences of the rrs genes (16S rRNA) of Mycoplasma conjunctivae was developed for direct detection and identification of this pathogen from clinical material. DNA from eye swabs was amplified after a simple lysis step by either a single PCR with the M. conjunctivae specific primer pair McoR1 and McoF1, or by a nested PCR with the Mycoplasma genus specific primer pair MOLIGEN1-L and 16UNI-R in the first step and McoR1 and McoF1 in the second step. The specificity of the primer pair McoR1 and McoF1 was verified with purified DNA from the type strain, from 17 field isolates of M. conjunctivae and from several Mollicutes which are phylogenetically related to M. conjunctivae or which can be isolated from the same host animals. This method identified mycoplasma isolates from goat, sheep, ibex and chamois originating from different countries as M. conjunctivae. No cross amplifications with other mycoplasmas which are related to M. conjunctivae were observed. Eye swab samples containing known numbers of M. conjunctivae cells were analysed after direct lysis of the material. The detection level was estimated to be 20 cells per swab when the nested PCR procedure was used and 2 x 10(5) by the single PCR method. In an experimental infection model of sheep, the nested PCR method for detection of M. conjunctivae gave results which were comparable to mycoplasmal culture. These are the implications for diagnostic purposes: M. conjunctivae isolates can be identified by the one-step PCR method, whereas for detection and identification of M. conjunctivae in clinical material the two-step method should be used (higher sensitivity).

PCR-based detection and typing of human adenoviruses in clinical samples

Since human adenoviruses (Ad) are associated with a variety of diseases, there is need for a fast and sensitive diagnostic procedure. The polymerase chain reaction (PCR) has been previously applied for the detection and typing of adenoviruses directly in clinical samples. So far, only Ad8, Ad31, Ad40 and Ad41 could be typed by PCR. To extend the technique of type-specific PCR to other adenovirus serotypes, type-specific primers for Ad1, Ad2, Ad4, Ad5, Ad19 and Ad37 were evaluated. In the present study, 50 stool and 68 eye swab specimens were first tested for the presence of adenoviruses using genus-specific primers. Adenoviruses could be detected in 42 stool and 47 eye swab samples. While the adenovirus-positive stool samples were subsequently typed with primers for Ad2, Ad5, Ad31, Ad40 and Ad41, the positive eye swab specimens were typed with primers for Ad4, Ad8, Ad19 and Ad37.

Detection of herpes simplex virus type 1 in herpetic ocular diseases by DNA-DNA hybridization using a biotinylated DNA probe.

A diagnostic hybridization assay for detecting herpes simplex virus type 1 (HSV-1) in ocular specimens was developed using cloned viral DNA as a probe. This hybridization assay is based on visualizing a biotinylated probe that is hybridized to the target DNA by a streptavidin/alkaline phosphatase system. The time required for performing this assay system is only two days. This assay system could detect a probe which had been hybridized to as little as 1 pg of homologous DNA and did not cross-react with DNA of other human herpes viruses except that of herpes simplex virus type 2 (HSV-2) which showed weak cross-reactivity. The assay system was applied to experimental keratitis in albino rabbits and clinical specimens. In experimental keratitis in rabbits it was possible to detect HSV-1 DNA in the eye swab samples at least until the ninth day after virus inoculation. Five clinical specimens collected from patients with corneal ulcer or blepharitis contained HSV-1 DNA in spite of the failure of demonstration of viral antigen and/or virus isolation in two cases.