Lesion Swabs Research Articles

Swab Protocol for Rapid Laboratory Diagnosis of Cutaneous Anthrax

The clinical laboratory diagnosis of cutaneous anthrax is generally established by conventional microbiological methods, such as culture and directly straining smears of clinical specimens. However, these methods rely on recovery of viable Bacillus anthracis cells from swabs of cutaneous lesions and often yield negative results. This study developed a rapid protocol for detection of B. anthracis on clinical swabs. Three types of swabs, flocked-nylon, rayon, and polyester, were evaluated by 3 extraction methods, the swab extraction tube system (SETS), sonication, and vortex. Swabs were spiked with virulent B. anthracis cells, and the methods were compared for their efficiency over time by culture and real-time PCR. Viability testing indicated that the SETS yielded greater recovery of B. anthracis from 1-day-old swabs; however, reduced viability was consistent for the 3 extraction methods after 7 days and nonviability was consistent by 28 days. Real-time PCR analysis showed that the PCR amplification was not impacted by time for any swab extraction method and that the SETS method provided the lowest limit of detection. When evaluated using lesion swabs from cutaneous anthrax outbreaks, the SETS yielded culture-negative, PCR-positive results. This study demonstrated that swab extraction methods differ in their efficiency of recovery of viable B. anthracis cells. Furthermore, the results indicated that culture is not reliable for isolation of B. anthracis from swabs at ≥ 7 days. Thus, we recommend the use of the SETS method with subsequent testing by culture and real-time PCR for diagnosis of cutaneous anthrax from clinical swabs of cutaneous lesions.

First-in-human phase I clinical trial of a recombinant vesicular stomatitis virus (rVSV)-based preventive HIV-1 vaccine

Methods HVTN 090 enrolled sixty healthy, HIV-1-uninfected adults in a randomized, double-blinded, placebo-controlled dose escalation study. Groups of 12 participants received rVSV Indiana HIV Gag vaccine at 5 dose levels (4.6 x 10 to 3.4 x 10 PFU) (N=10/group) or placebo (N=2/group), delivered intramuscularly at 0 and 2 months. Reactogenicity over 7 days, adverse events (AEs), and viral cultures from whole blood, urine, saliva and swabs of oral lesions were collected. HIV-1-specific CD4+ and CD8+ T-cell responses to Gag peptides were measured 1 and 2 weeks post-boost by intracellular cytokine staining.

Epidemiology, clinical features and diagnosis of Mycobacterium ulcerans in an Australian population

To describe the epidemiology, clinical features and diagnosis of Mycobacterium ulcerans infection occurring on the Bellarine Peninsula in Victoria. Analysis of prospectively collected data on all patients with confirmed M. ulcerans infection reported from the Bellarine Peninsula and managed at Barwon Health between 1 January 1998 and 2 September 2011. Proportion of cases by age group and sex; duration of symptoms; number, type and site of lesions; proportions diagnosed by polymerase chain reaction (PCR) testing and mycobacterial cultures. We identified 180 sequential cases of M. ulcerans infection: 42 cases in 1998-2004 and 138 in 2005-2011. Median patient age was 61 years (range, 1-94 years), and 49% of patients were male. Duration of symptoms before diagnosis varied from 2 to 270 days (median, 42 days). At presentation, 95% of patients had single lesions. Lower limbs were the most common site of lesions (61%), followed by upper limbs (34%); 40% occurred over a joint. Most lesions presented as ulcers (87%). Compared with the rest of the study population, patients aged > 60 years were more likely to have multiple lesions (odds ratio [OR], 8.1; 95% CI, 1.0-176.2; P = 0.04), and patients aged < 15 years were less likely to have lesions over a joint (OR, 0.2; 95% CI, 0.0-1.0; P = 0.02). Upper limb lesions were more common (OR, 2.2; 95% CI, 1.1-4.3; P = 0.02) and lower limb lesions less common (OR, 0.5; 95% CI, 0.5-0.9; P = 0.01) in male than female patients. Lesion swabs were PCR-positive in 99% of those tested, and positive on mycobacterial culture in 19%. Lesion biopsy samples were PCR-positive in 95% and mycobacterial culture-positive in 47%. M. ulcerans infections are increasing in the Bellarine Peninsula. They usually present as single ulcerative lesions on limbs, commonly over joints. Age and sex influence clinical presentation, and PCR of lesions has high diagnostic sensitivity.

Epidemiology of Mycoplasma bovis in Pennsylvania veal calves

The objective of the study was to estimate the prevalence and incidence of Mycoplasma bovis, a common cause of pneumonia, in veal calves. Using simple random sampling, 252 calves from 4 veal herds located in central Pennsylvania were selected and longitudinally followed for monthly collection of nasal swabs. Bronchial swabs and lung lesions were collected at the slaughterhouse. Nasal, bronchial, and lung lesion swabs were cultured for bacterial respiratory pathogens. Ninety lung lesions were identified, of which 41.1, 1.1, 1.1, 7.8, and 4.4% were culture positive for M. bovis alone, Pasteurella multocida alone, Mannheimia haemolytica alone, M. bovis and P. multocida co-infection, and M. bovis and M. haemolytica co-infection, respectively. The data indicate that potential interventions, such as therapeutics, vaccines, or management control measures, would be most effective before 50 d of age based upon the cumulative incidence of colonization.

Localised Mycobacterium ulcerans infection in four dogs

Localised infection caused by Mycobacterium ulcerans is described in two Kelpies, a Whippet and a Koolie domiciled on the Bellarine Peninsula, Victoria, Australia. The diagnosis was confirmed using real-time polymerase chain reaction (PCR) targeting the M. ulcerans-specific insertion sequence (IS2404) in DNA extracted from swabs of ulcerated lesions in all cases. Where available, molecular typing confirmed that three of the dogs were infected with a strain of M. ulcerans that was indistinguishable from a disease-causing strain in people and other animals in Victoria. One dog was still undergoing treatment at the time of writing, but the remaining three dogs were successfully treated with a combination of surgical debridement and medical therapy in one case, and medical therapy alone in the other two. Investigation of the home environs of three of the dogs using real-time PCR revealed low amounts of M. ulcerans DNA in various environmental samples. Mycobacterium ulcerans infection should be included in the differential diagnoses of any ulcerated skin lesions in dogs that live in or visit endemic areas of Victoria and Queensland.

Adanya korelasi kadar TNF-α antara pemeriksaan hapusan lesi dengan pemeriksaan darah perifer pasien stomatitis aftosa rekuren Correlation of TNF-α between lesional swab and peripheral blood of mononuclear cell of recurrent aphthous stomatitis patient

Recurrent aphthous stomatitis (RAS)is a common oral mucosal disease in human. This disease affect 20-25% ofpopulation. The etiology remains unclear, but some of cytokine such as TNF-α is suspected to contribute in thepathogenesis of RAS. TNF-α is commonly measured by PBMC and lesional biopsy. These are invasive method andhigh skilled requirement. Another study used lesional swab to measure this cytokine without correlating the resultwith TNF-α measured by PBMC level. This study aimed to asses TNF-α level correlation between lesional swab andPBM of RAS patients. The study involved 10 subjects by inclusion criteria. Subjects have lesion swab and PBMCexamined. Samples were analyzed by ELISA method. There is a correlation between lesional swab and PBMC ofTNF-α level RAS patients but this correlation did not statistically significant.

Topical 5-fluorouracil treatment of anal intraepithelial neoplasia in human immunodeficiency virus-positive men

Anal intraepithelial neoplasia (AIN), a human papillomavirus (HPV)-induced potential precursor lesion of anal cancer, is frequent among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). So far, only a few prospective studies have been performed on the topical treatment of AIN, especially at the intra-anal location. To evaluate the efficacy and safety of self-administered topical 5-fluorouracil (5-FU) treatment of AIN in HIV-positive MSM. High-resolution anoscopy (HRA) was performed and patients with AIN (grade 1-3) were treated with 5-FU twice weekly for a total of 16 weeks. HRA-guided lesional biopsies were repeated after 5-FU treatment for histopathological evaluation. Lesional swabs were obtained before and after treatment for HPV typing and HPV-DNA load determination of the high-risk types HPV16, 18, 31 and 33. Responding patients returned 6 months after treatment for follow-up. A total of 46 patients with AIN were included in this open prospective pilot study; 76% had multifocal disease and 74% had high-grade lesions (AIN 2 or 3). In an intention-to-treat analysis, 26 of 46 patients (57%) responded to 5-FU treatment. Eighteen patients (39%) had a complete clearance of AIN and eight patients (17%) had a partial response. Seventeen patients (37%) did not respond (unchanged grade of AIN in 16 patients and progression from low- to high-grade AIN in one patient). 5-FU treatment led to a significant decrease of HPV16-DNA load and cumulative high-risk HPV-DNA load in both responding and nonresponding patients. Thirty-nine patients (85%) experienced side-effects during therapy, but only two discontinued 5-FU treatment. One patient was lost to follow-up. Six months later, 50% of the complete responders had a recurrence. A substantial proportion of HIV-positive MSM with AIN completely cleared their lesions with topical 5-FU treatment. In those with partial response, pretreatment with topical 5-FU might facilitate subsequent ablative therapy.

A boy with a one-sided red rash

We report on a boy with a sudden onset of unilateral skin lesions following tonsillar infection with fever 2 weeks before. The lesions consisted of erythematous macules with scaling affecting trunk, axillar, as well as inguinal region. CRP, blood differential, serum IgG and IgM antibodies (coxsackievirus, cytomegalovirus, parvovirus, herpes virus, varicella zoster virus, human herpesvirus-6/-7), and lesional swabs (bacteria, dermatophytes, yeasts) were uneventful.

Rapid Polymerase Chain Reaction Assay to Detect Herpes Simplex Virus in the Genital Tract of Women in Labor

To develop a rapid quantitative real-time polymerase chain reaction (PCR) to detect herpes simplex virus (HSV) in the genital secretions of women that may be used in labor. Samples of genital secretions from women in labor, swabs of active genital lesions, and swabs of buffer solution were analyzed using a newly developed rapid HSV PCR assay to detect HSV glycoprotein B gene and quantitate virion copy number. A previously validated TaqMan PCR to detect HSV glycoprotein B gene was performed as the comparator gold standard. Positivity determination that optimized sensitivity and specificity was determined with receiver operating characteristic curves. The median time to result for rapid HSV PCR was 2 hours (range 1.5-3.5 hours). A positivity determination rule that required both wells of the rapid test to detect 150 copies or greater of HSV per milliliter maximized specificity (96.7%) without appreciable loss of sensitivity (99.6%). Among positive samples, the correlation between the rapid test and TaqMan for the quantity of HSV isolated was excellent (R=0.96, P<.001). The rapid test had a positive predictive value of 96.7% and a negative predictive value of 99.6% in a population with HSV shedding prevalence of 10.8%, based on the prevalence of genital HSV previously found among HSV-2 seropositive women in labor. Rapid HSV PCR provides results with excellent sensitivity and specificity within a timeframe that could inform clinical decision making for identifying neonates at risk of neonatal HSV infection. II.

Viremia in Acute Herpes Zoster

A phase 2 trial was conducted to evaluate the efficacy of a topical antiviral, sorivudine, as an adjuvant to valacyclovir for the treatment of acute herpes zoster. In this randomized, placebo-controlled, double-blind trial, 25 patients were treated with either sorivudine or placebo cream. All patients began 7 days of valacyclovir treatment on day 3. Zoster lesion swab samples and samples of peripheral blood mononuclear cells were collected periodically throughout the study and were analyzed for varicella-zoster virus (VZV) DNA by use of both qualitative and real-time polymerase chain reaction. Serum samples collected periodically throughout the study were analyzed for VZV DNA by use of real-time polymerase chain reaction. VZV DNA was detected in all 3 sample types, and the number of viral copies correlated with the progression of herpes zoster. No statistically significant differences were seen between the placebo- and sorivudine-treated groups with respect to clinical characteristics or laboratory test results. The detection of VZV DNA in the serum and peripheral blood mononuclear cells of all 25 zoster patients documents that viremia is a common manifestation of herpes zoster. Sorivudine cream appears to be a safe and well-tolerated adjuvant therapy; however, further phase 2 studies are needed to determine its clinical efficacy for the treatment of herpes zoster. Trials registration. ClinicalTrials.gov identifier: NCT00652184.

Diagnosis of Queensland Tick Typhus and African Tick Bite Fever by PCR of Lesion Swabs

We report 3 cases of Queensland tick typhus (QTT) and 1 case of African tick bite fever in which the causative rickettsiae were detected by PCR of eschar and skin lesions in all cases. An oral mucosal lesion in 1 QTT case was also positive.

Assessment of a real-time PCR test to diagnose syphilis from diverse biological samples

Objectives:To investigate the contribution of a real-time PCR assay for the detection of Treponema pallidum in various biological specimens with the secondary objective of comparing its value according to HIV...

Healthcare Seeking and Sexual Behavior Among Patients with Symptomatic Newly Acquired Genital Herpes

Symptoms among patients with first episode herpes simplex virus (HSV) likely influence health seeking and sexual behavior. An improved understanding of this relationship provides insight into the experience of having genital herpes and has implications for counseling. To describe the healthcare seeking and sexual behavior in patients with symptomatic laboratory confirmed first episode HSV infection. Two hundred thirty-six patients (94 men and 142 women) with newly acquired genital herpes were asked to complete a demographic and sexual history questionnaire. To confirm initial HSV diagnosis, swabs of lesions were collected for viral culture and HSV DNA polymerase chain reaction and blood was drawn for confirmation of HSV serostatus using the Western blot. Women reported pain and men reported lesions as the most frequent and bothersome symptom or sign causing each to seek healthcare. Forty-three percent of all participants missed some work or school because of their symptoms; women missed more school or work, sought care sooner, and saw more providers than men. Before diagnosis, most respondents (67%) suspected genital herpes was the etiology of the symptoms. Twenty-seven percent reported having sex after noticing their symptoms, though those who missed more school or work were less likely to engage in sexual intercourse. Men and women have different experiences with first episode HSV, but morbidity is substantial, especially among women. Both men and women may continue to engage in sexual activity after onset of genital herpes, emphasizing the need for providers to counsel their patients to avoid exposing partners to the infection.

Use of topical povidone‐iodine resulting in an iododerma‐like eruption

Iododerma is a rare skin eruption that is usually induced by the systemic use of iodide-containing radiographic contrast medium or treatment with oral potassium iodide therapy. Iododerma has also rarely been reported to occur following topical application of iodine. We herein report the case of a 42-year-old male who developed multiple pinpoint pustules on both lower extremities. Three days after the eruption began, the patient started applying topical 10% povidone-iodine solution to the lesions. During this treatment, the lesions enlarged into multiple 2-9-cm pus-filled bullae, limited to the treated areas. Lesional bacterial culture swab and Gram stain were negative. Blood cultures were also negative and the patient's white blood cell count was normal. A punch biopsy specimen revealed pseudoepitheliomatous hyperplasia and dermal-epidermal separation with epidermal necrosis and underlying abscess formation. A superficial and deep perivascular, interstitial and perifollicular infiltrate containing numerous neutrophils, with abscess formation and eosinophils was also seen. This histology was consistent with iododerma and the patient's lesions involuted following cessation of topical iodine use, leaving only post-inflammatory hyperpigmentation. In summary, our patient likely had a folliculitis that was then treated with topical povidone-iodine that led to iododerma. Although it remains possible that the reaction was an unusual contact hypersensitivity response, the ulceration, pseudoepitheliomatous hyperplasia and abscess formation do support an iododerma-like eruption.

Disseminated gonococcal infection in a homosexual man diagnosed by nucleic acid amplification testing from a skin lesion swab

Disseminated gonococcal infection (DGI) often presents a diagnostic challenge. Through the novel application of molecular technology, a case is presented that suggests how the diagnostic sensitivity for this systemic complication...

Skin infections among Indigenous Australians in an urban setting in Far North Queensland

Skin infections are highly prevalent in many Australian Aboriginal communities. This study aimed to determine the prevalence of group A streptococcus (GAS) and Staphylococcus aureus in skin sores of Indigenous people living in an urban setting. We undertook a cross-sectional study of 173 children and youths attending the Wuchopperen Clinic (Cairns) for treatment of skin infections. Participants were interviewed using a structured questionnaire, and a skin lesion swab obtained. The median age was 5.3 years, with 42% identifying themselves as Torres Strait Islanders and 34% as Aboriginal. Impetigo (65%) was the most frequent diagnosis reported followed by scabies (19%); 79% of the lesions had erythema and 70% had exudate. Of 118 lesions, 114 were positive for pathogenic bacteria, with GAS isolated in 84 cases and S. aureus in 92; both these species were recovered from 63 lesions. Significant diversity of emm-types of GAS was associated with skin lesions in Indigenous patients (22 emm-types identified). Fifteen of the 92 S. aureus isolates were suggestive of being community-acquired on the basis of antimicrobial susceptibility profile and nine of these strains were co-cultured from nine lesions. These results have implications for future changes of antibiotic policies for the treatment of skin infections in this population.

Cervicovaginal HIV-1 and herpes simplex virus type 2 shedding during genital ulcer disease episodes

To investigate correlates of herpes simplex virus type 2 (HSV-2) DNA and HIV-1 RNA among women with genital ulcer disease (GUD). Baseline data from a randomized placebo-controlled trial of episodic herpes treatment in Ghana and the Central African Republic. GUD aetiology was determined by polymerase chain reaction (PCR) from a lesional swab. Real-time PCR was used to quantify HIV-1 RNA, and HSV-2 DNA in cervicovaginal lavages (CVL) and HIV-1 RNA in plasma. Genital infection was defined as the presence of virus in the lesion or CVL. Of 441 women enrolled, 79.0% were HSV-2 seropositive, 46.6% were HIV-1 seropositive, and 50.0% had an HSV-2 ulcer. Among 180 HSV-2/HIV-1 co-infected women, cervicovaginal HIV-1 RNA was detected more frequently in women with HSV-2 ulcers (67.9%) or cervicovaginal HSV-2 DNA only (72.3%) compared with women without genital HSV-2 infection (42.4%) (P = 0.004). Women with genital HSV-2 infection had higher median cervicovaginal HIV-1-RNA loads (3.14 log10 copies/mL versus 2.10 log10 copies/mL; P = 0.003), higher plasma HIV-1-RNA loads (median 5.10 versus 4.65 log10 copies/mL; P = 0.07), and lower median CD4 cell counts) (198 versus 409 cells/mm, P = 0.03). Cervicovaginal HIV-1 RNA and HSV-2 DNA were significantly correlated after adjusting for plasma HIV-1 RNA and CD4 cell counts (P < 0.001) and a 10-fold increase in cervicovaginal HSV-2 DNA was associated with a 1.7-fold increase in plasma HIV-1 RNA (P = 0.003). Genital HSV-2 infection is associated with increased cervicovaginal and plasma HIV-1 RNA among co-infected women with genital ulcers, independently of the level of immunodeficiency, highlighting the close interaction between these two viruses and the role of HSV-2 as a co-factor for the sexual transmission of HIV-1.

Characterization of Klebsiella pneumoniae isolates from New Zealand sea lion ( Phocarctos hookeri) pups during and after the epidemics on Enderby Island, Auckland Islands

The 2001/2002 and 2002/2003 breeding seasons of New Zealand sea lions (NZSLs) on the Auckland Islands were marked by a high pup mortality caused by acute bacterial infections. As part of a health survey from 1998/1999 to 2004/2005, tissues and swabs of lesions had been collected at necropsy to identify the bacteria associated with pup mortality. Klebsiella pneumoniae was grown in pure culture from 83% of various organs and lesions in 2001/2002 and 76% in 2002/2003, and less frequently in the following seasons (56% in 2003/2004 and 49% in 2004/2005). Pup isolates of K. pneumoniae showed identical minimal inhibitory concentrations (MIC) of cefuroxime, neomycin, cephalotin, cephalexin and dihydrostreptomycin, suggesting clonal aetiology of the pathogen. Isolates also tested negative for production of extended-spectrum beta-lactamases (ESBLs), which was not in favour of an anthropogenetic origin of the epidemic strain. Pulsed-field gel electrophoresis (PFGE) of XbaI DNA macrorestriction fragments was performed on isolates of K. pneumoniae and Klebsiella oxytoca from 35 pups, thee NZSL adult females, and from three human patients for comparison. PFGE showed that pup isolates of K. pneumoniae were genetically indistinguishable but were neither related to K. pneumoniae from humans and from NZSL adults, nor to K. oxytoca from NZSLs. It is concluded that the 2001/2002 and 2002/2003 epidemics at Sandy Bay rookery were caused by a single K. pneumoniae clonal lineage, genetically different from the strain carried by adult NZSLs. An anthropogenic origin of the K. pneumoniae clone could not be confirmed, but further investigations are required to rule-out such occurrence.

Group a Streptococcal Carriage among Residents of an Urban Homeless Shelter

Group a Streptococcal Carriage among Residents of an Urban Homeless Shelter

Nursing Home Outbreak of Invasive Group A Streptococcal Infections Caused by 2 Distinct Strains

Objective.To identify factors contributing to a cluster of deaths from invasive group A streptococcus (GAS) infection in a nursing home facility and to prevent additional cases.Design.Outbreak investigation.Setting.A 146-bed nursing home facility in northern Nevada.Methods.We defined a case as the isolation of GAS from a normally sterile site in a resident of nursing home A. To identify case patients, we reviewed resident records from nursing home A, the local hospital, and the hospital laboratory. We obtained oropharyngeal and skin lesion swabs from staff and residents to assess GAS colonization and performed emm typing on available isolates. To identify potential risk factors for transmission, we performed a cohort study and investigated concurrent illness among residents and surveyed staff regarding infection control practices.Results.Six residents met the case patient definition; 3 (50%) of them died. Among invasive GAS isolates available for analysis, 2 distinct strains were identified: emm11 (3 isolates) and emm89 (2 isolates). The rate of GAS carriage was 6% among residents and 4% among staff; carriage isolates were emm89 (8 isolates), emm11 (2 isolates), and emm1 (1 isolate). Concurrently, 35 (24%) of the residents developed a respiratory illness of unknown etiology; 41% of these persons died. Twenty-one (30%) of the surveyed employees did not always wash their hands before patient contacts, and 27 (38%) did not always wash their hands between patient contacts.Conclusions.Concurrent respiratory illness likely contributed to an outbreak of invasive GAS infection from 2 strains in a highly susceptible population. This outbreak highlights the importance of appropriate infection control measures, including respiratory hygiene practices, in nursing home facilities.