Immune Mediated Shaping of Microflora Community Composition Depends on Barrier Site

Barrier surfaces, such as the intestinal lining and the skin, are colonized by a diverse community of commensal microorganisms. Although commensal microorganisms clearly impact the host immune system, whether the immune system also shapes the commensal community is poorly understood. We used 16S rDNA deep sequencing to test whether mice with specific immune defects have an altered commensal microflora. Initially, skin swabs were obtained from wild-type and Langerhans Cell (LC) deficient mice. Despite the intimate contacts that LC make with the upper epidermis, no significant differences were observed in microbial community composition. Similarly, the skin of MyD88/TRIF^−/−, Rag1^−/− and heterozygous littermate controls showed no alteration in their commensal communities. Next we examined mouth swabs and feces. We did not find a difference in the MyD88/TRIF^−/− mice. However, we did observe a significant shift in the microbial composition in the feces and mouths of Rag1^−/− mice. Thus, we conclude that the adaptive immune system modulates the microbial composition at mucosal surfaces in the steady-state but LC, adaptive immunity, and MyD88-dependent innate responses do not affect the skin microbiome revealing a major distinction between barrier sites.     

Vibration response imaging: a novel noninvasive tool for evaluating the initial therapeutic effect of noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease

Background

The popular methods for evaluating the initial therapeutic effect (ITE) of noninvasive positive pressure ventilation (NPPV) can only roughly reflect the therapeutic outcome of a patient’s ventilation because they are subjective, invasive and time-delayed. In contrast, vibration response imaging (VRI) can monitor the function of a patient’s ventilation over the NPPV therapy in a non-invasive manner. This study aimed to investigate the value of VRI in evaluating the ITE of NPPV for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

Thirty-six AECOPD patients received VRI at three time points: before NPPV treatment (T1), at 15 min of NPPV treatment (T2), and at 15 min after the end of NPPV treatment (T4). Blood gas analysis was also performed at T1 and at 2 hours of NPPV treatment (T3). Thirty-nine healthy volunteers also received VRI at T1 and T2. VRI examination at the time point T2 in either the patients or volunteers did not require any interruption of the on-going NPPV. The clinical indices at each time point were compared between the two groups. Moreover, correlations between the PaCO₂ changes (T3 vs T1) and abnormal VRI scores (AVRIS) changes (T2 vs T1) were analyzed.

Results

No significant AVRIS differences were found between T1 and T2 in the healthy controls (8.51 ± 3.36 vs. 8.53 ± 3.57, P > 0.05). The AVRIS, dynamic score, MEF score and EVP score showed a significant decrease in AECOPD patients at T2 compared with T1 (P < 0.05), but a significant increase at T4 compared with T2 (P < 0.05). We also found a positive correlation (R² = 0.6399) between the PaCO₂ changes (T3 vs T1) and AVRIS changes (T2 vs T1).

Conclusions

VRI is a promising noninvasive tool for evaluating the initial therapeutic effects of NPPV in AECOPD patients and predicting the success of NPPV in the early stage.     

Molecular Comparison of Bacterial Communities on Peripheral Intravenous Catheters and Matched Skin Swabs

Skin bacteria at peripheral intravenous catheter (PIVC) insertion sites pose a serious risk of microbial migration and subsequent colonisation of PIVCs, and the development of catheter related bloodstream infections (CRBSIs). Common skin bacteria are often associated with CRBSIs, therefore the bacterial communities at PIVC skin sites are likely to have major implications for PIVC colonisation. This study aimed to determine the bacterial community structures on skin at PIVC insertion sites and to compare the diversity with associated PIVCs. A total of 10 PIVC skin site swabs and matching PIVC tips were collected by a research nurse from 10 hospitalised medical/surgical patients at catheter removal. All swabs and PIVCs underwent traditional culture and high-throughput sequencing. The bacterial communities on PIVC skin swabs and matching PIVCs were diverse and significantly associated (correlation coefficient = 0.7, p<0.001). Methylobacterium spp. was the dominant genus in all PIVC tip samples, but not so for skin swabs. Sixty-one percent of all reads from the PIVC tips and 36% of all reads from the skin swabs belonged to this genus. Staphylococcus spp., (26%), Pseudomonas spp., (10%) and Acinetobacter spp. (10%) were detected from skin swabs but not from PIVC tips. Most skin associated bacteria commonly associated with CRBSIs were observed on skin sites, but not on PIVCs. Diverse bacterial communities were observed at skin sites despite skin decolonization at PIVC insertion. The positive association of skin and PIVC tip communities provides further evidence that skin is a major source of PIVC colonisation via bacterial migration but microbes present may be different to those traditionally identified via culture methods. The results provide new insights into the colonisation of catheters and potential pathogenesis of bacteria associated with CRBSI, and may assist in developing new strategies designed to reduce the risk of CRBSI.     

Magnitude of colonization and sepsis by group B streptococci in newborn infants

Infants admitted to the Neonatal Intensive Care Unit at Tampa General Hospital, Tampa, Florida, were cultured for group B streptococci (GBS). Culture swabs were quantified for GBS to determine the magnitude of colonization in infected infants. Thirty-seven (17%) of the 217 infants cultured were positive for GBS. Six of these colonized infants developed sepsis, with blood cultures positive for GBS. Septic infants generally were colonized by large numbers of GBS (10⁵ bacteria/culture swab) at two or more external skin sites, in comparison to aseptic infants, who were lightly colonized with GBS. The data suggest a possible correlation between magnitude of colonization by GBS at external skin sites and development of GBS sepsis in newborn infants.     

Minimally invasive sampling to identify leprosy patients with a high bacterial burden in the Union of the Comoros

The World Health Organization (WHO) endorsed diagnosis of leprosy (also known as Hansen’s disease) entirely based on clinical cardinal signs, without microbiological confirmation, which may lead to late or misdiagnosis. The use of slit skin smears is variable, but lacks sensitivity. In 2017–2018 during the ComLep study, on the island of Anjouan (Union of the Comoros; High priority country according to WHO, 310 patients were diagnosed with leprosy (paucibacillary = 159; multibacillary = 151), of whom 263 were sampled for a skin biopsy and fingerstick blood, and 260 for a minimally-invasive nasal swab. In 74.5% of all skin biopsies and in 15.4% of all nasal swabs, M. leprae DNA was detected. In 63.1% of fingerstick blood samples, M. leprae specific antibodies were detected with the quantitative αPGL-I test. Results show a strong correlation of αPGL-I IgM levels in fingerstick blood and RLEP-qPCR positivity of nasal swabs, with the M. leprae bacterial load measured by RLEP-qPCR of skin biopsies. Patients with a high bacterial load (≥50,000 bacilli in a skin biopsy) can be identified with combination of counting lesions and the αPGL-I test. To our knowledge, this is the first study that compared αPGL-I IgM levels in fingerstick blood with the bacterial load determined by RLEP-qPCR in skin biopsies of leprosy patients. The demonstrated potential of minimally invasive sampling such as fingerstick blood samples to identify high bacterial load persons likely to be accountable for the ongoing transmission, merits further evaluation in follow-up studies.     

Equivalence of Self- and Staff-Collected Nasal Swabs for the Detection of Viral Respiratory Pathogens

Background

The need for the timely collection of diagnostic biosamples during symptomatic episodes represents a major obstacle to large-scale studies on acute respiratory infection (ARI) epidemiology. This may be circumvented by having the participants collect their own nasal swabs. We compared self- and staff-collected swabs in terms of swabbing quality and detection of viral respiratory pathogens.

Methodology/Principal Findings

We conducted a prospective study among employees of our institution during the ARI season 2010/2011 (December-March). Weekly emails were sent to the participants (n = 84), reminding them to come to the study center in case of new symptoms. The participants self-collected an anterior nasal swab from one nostril, and trained study personnel collected one from the other nostril. The participants self-collected another two swabs (one from each nostril) on a subsequent day. Human β-actin DNA concentration was determined in the swabs as a quality control. Viral respiratory pathogens were detected by multiplex RT-PCR (Seeplex RV15 kit, Seegene, Eschborn, Germany). Of 84 participants, 56 (67%) reported at least one ARI episode, 18 participants two, and one participant three. Self-swabbing was highly accepted by the participants. The amount of β-actin DNA per swab was higher in the self- than in the staff-collected swabs (p = 0.008). β-actin concentration was lower in the self-swabs collected on day 1 than in those collected on a subsequent day (p<0.0001). A respiratory viral pathogen was detected in 31% (23/75) of staff- and in 35% (26/75) of self-collected swabs (p = 0.36). With both approaches, the most frequently identified pathogens were human rhinoviruses A/B/C (12/75 swabs, 16%) and human coronavirus OC43 (4/75 swabs, 5%). There was almost perfect agreement between self- and staff-collected swabs in terms of pathogen detection (agreement = 93%, kappa = 0.85, p<0.0001).

Conclusions/Significance

Nasal self-swabbing for identification of viral ARI pathogens proved to be equivalent to staff-swabbing in this population in terms of acceptance and pathogen detection.     

The evaluation of skin disinfection efficacy and its influence on prevalence of surgical site infections in patients subjected to laparoscopic cholecystectomy

Laparoscopic cholecystectomy (LC) is "the method of choice" in the treatment of cholelithiasis and its' complications. LC is not devoid of complications, among others, surgical site infection (SSI) but as a result of minimalisation of surgical trauma and immunosuppression after surgery, percentage of SSI is lower than after conventional cholecystectomy. Skin disinfection carried out before operation is thought to minimalise risk of infective complications after LC. 150 patients who had laparoscopic cholecystectomy carried out, were included in prospective study. Efficacy of skin disinfection was based on microbiological assessment including swabs from the umbiliculus before and after skin disinfection, and samples of exsudate or discharge from surgical site (if any). There were 133 (88.6%) patients with positive result of the umbilical swab before the disinfection of the skin, whereas 26 (17.3%) patients had bacteria isolated from the umbilical swab after the disinfection. Among these 26 patients in 19 (73.1%) cases the same species of bacteria were isolated before and after skin disinfection. Among 19 patients with inefficient skin dissinfection in 2 cases we observed SSI. In one of them the same strains of bacteria were isolated from umbilical swab and surgical site. Analysis of drug sensitivity of these isolates showed strict correlation. There were 16 cases of SSI in the whole group and it's rate was 10,6%. Skin disinfection before LC is not fully efficient. Inefficiency of skin disinfection does not increase risk of SSI. Skin dissinfection reduce microbial flora but does not protect from SSI provoked by these microbials.     

Epidemiology and Clinical Characteristics of Respiratory Infections Due to Adenovirus in Children Living in Milan,Italy, during 2013 and 2014

To evaluate the predominant human adenovirus (HAdV) species and types associated with pediatric respiratory infections, nasopharyngeal swabs were collected from otherwise healthy children attending an emergency room in Milan, Italy, due to a respiratory tract infection from January 1 to February 28 of two subsequent years, 2013 and 2014. The HAdVs were detected using a respiratory virus panel fast assay (xTAG RVP FAST v2) and with a HAdV-specific real-time polymerase chain reaction; their nucleotides were sequenced, and they were tested for positive selection. Among 307 nasopharyngeal samples, 61 (19.9%) tested positive for HAdV. HAdV was the only virus detected in 31/61 (50.8%) cases, whereas it was found in association with one other virus in 25 (41.0%) cases and with two or more viruses in 5 (8.2%) cases. Human Enterovirus/human rhinovirus and respiratory syncytial virus were the most common co-infecting viral agents and were found in 12 (19.7%) and 7 (11.5%) samples, respectively. Overall, the HAdV strain sequences analyzed were highly conserved. In comparison to HAdV-negative children, those infected with HAdV had a reduced frequency of lower respiratory tract involvement (36.1% vs 55.2%; p = 0.007), wheezing (0.0% vs 12.5%; p = 0.004), and hospitalization (27.9% vs 56.1%; p<0.001). Antibiotic therapy and white blood cell counts were more frequently prescribed (91.9% vs 57.1%; p = 0.04) and higher (17,244 ± 7,737 vs 9,565 ± 3,211 cells/μL; p = 0.04), respectively, in children infected by HAdV-C than among those infected by HAdV-B. On the contrary, those infected by HAdV-B had more frequently lower respiratory tract involvement (57.1% vs 29.7%) but difference did not reach statistical significant (p = 0.21). Children with high viral load were absent from child care attendance for a longer period of time (14.5 ± 7.5 vs 5.5 ± 3.2 days; p = 0.002) and had higher C reactive protein levels (41.3 ± 78.5 vs 5.4 ± 9.6 μg/dL; p = 0.03). This study has shown that HAdV infections are diagnosed more commonly than usually thought and that HAdVs are stable infectious agents that do not frequently cause severe diseases. A trend toward more complex disease in cases due to HAdV species C and in those with higher viral load was demonstrated. However, further studies are needed to clarify factors contributing to disease severity to understand how to develop adequate preventive and therapeutic measures.     

皮肤共生菌在皮肤健康和疾病中的作用研究进展

人体皮肤上有多种微生物定居,这些微生物群落的组成、分布和动态变化对皮肤的健康状况和疾病有着重要的调节作用.然而,人们一直不清楚皮肤微生物群落如何影响人类健康.对皮肤共生菌进行深入研究,不仅有助于发现有益皮肤共生菌菌株,也有助于筛选相应皮肤疾病新的药物靶标.近年来,对皮肤共生菌与宿主之间相互影响和作用机制的研究逐渐深入,...     

Meningitis patients with Angiostrongylus cantonensis may present without eosinophilia in the cerebrospinal fluid in northern Vietnam

BackgroundEosinophilic meningitis (EM) is a rare clinical syndrome caused by both infectious and noninfectious diseases. In tropical pacific countries, Angiostrongylus cantonensis is the most common cause. However, the EM definition varies in the literature, and its relation to parasitic meningitis (PM) remains unclear.Methodology/Principal findingsAdult and adolescent patients of 13 years old or above with suspected central nervous system (CNS) infections with abnormal CSF findings were prospectively enrolled at a tertiary referral hospital in Hanoi, Vietnam from June 2012 to May 2014. Patients with EM or suspected PM (EM/PM) were defined by the presence of either ≥10% eosinophils or an absolute eosinophil cell counts of ≥10/mm³ in the CSF or blood eosinophilia (>16% of WBCs) without CSF eosinophils. In total 679 patients were enrolled: 7 (1.03%) had ≥10% CSF eosinophilia, 20 (2.95%) had ≥10/mm³ CSF eosinophilia, and 7 (1.03%) had >16% blood eosinophilia. The patients with ≥10% CSF eosinophilia were significantly younger (p = 0.017), had a lower body temperature (p = 0.036) than patients with ≥10/mm³ CSF eosinophilia among whom bacterial pathogens were detected in 72.2% (13/18) of those who were tested by culture and/or PCR. In contrast, the characteristics of the patients with >16% blood eosinophilia resembled those of patients with ≥10% CSF eosinophilia. We further conducted serological tests and real-time PCR to identify A. cantonensis. Serology or real-time PCR was positive in 3 (42.8%) patients with ≥10% CSF eosinophilia and 6 (85.7%) patients with >16% blood eosinophilia without CSF eosinophils but none of patients with ≥10/mm³ CSF eosinophilia.ConclusionsThe etiology of PM in northern Vietnam is A. cantonensis. The eosinophil percentage is a more reliable predictor of parasitic EM than absolute eosinophil count in the CSF. Patients with PM may present with a high percentage of eosinophils in the peripheral blood but not in the CSF.     

Chronic HIV Infection Enhances the Responsiveness of Antigen Presenting Cells to Commensal Lactobacillus

Chronic immune activation despite long-term therapy poses an obstacle to immune recovery in HIV infection. The role of antigen presenting cells (APCs) in chronic immune activation during HIV infection remains to be fully determined. APCs, the frontline of immune defense against pathogens, are capable of distinguishing between pathogens and non-pathogenic, commensal bacteria. We hypothesized that HIV infection induces dysfunction in APC immune recognition and response to some commensal bacteria and that this may promote chronic immune activation. Therefore we examined APC inflammatory cytokine responses to commensal lactobacilli. We found that APCs from HIV-infected patients produced an enhanced inflammatory response to Lactobacillus plantarum WCFS1 as compared to APCs from healthy, HIV-negative controls. Increased APC expression of TLR2 and CD36, signaling through p38-MAPK, and decreased expression of MAP kinase phosphatase-1 (MKP-1) in HIV infection was associated with this heightened immune response. Our findings suggest that chronic HIV infection enhances the responsiveness of APCs to commensal lactobacilli, a mechanism that may partly contribute to chronic immune activation.     

Fecal microflora of Greek healthy neonates

This study aimed to explore, in our geographical region, the development of intestinal microflora and the colonization patterns of lactic acid bacteria and bifidobacteria during the first three months of life and to investigate the effect of the mode of delivery. Fecal specimens from 82 healthy, full-term infants were collected prospectively 4, 30 and 90 days after delivery and subcultured on nonselective and selective media. Identification of isolates was performed by microbiological and molecular methods. For the delivery effect, two groups of vaginally or caesarean-delivered exclusively breast-fed infants were studied. Despite the early high total counts of aerobes and anaerobes, colonization of lactobacilli and bifidobacteria was overall limited until 3 months of age. Furthermore, caesarean-delivered infants were less often colonized with lactobacilli at day 4 (4% vs. 59%, p = 0.000) and with bifidobacteria at day 4 (0% vs. 23%, p = 0.015) and 30 (0% vs. 35%, p = 0.042) compared to vaginally delivered ones. No bacterial populations differences were detected to compare colonized infants. Identification results indicated the predominance of Lactobacillus rhamnosus, Lactobacillus johnsonii and Lactobacillus paracasei species in neonatal gut microflora up to the first month of life and diversity of Lactobacillus species in vaginally delivered, colonized newborns, at fourth day. Furthermore, Bifidobacterium longum and Bifidobacterium breve were the most frequently detected Bifidobacterium species in vaginally delivered, breast-fed infants. In conclusion our study revealed a restricted colonization pattern of lactic acid bacteria in Greek infants and a delay in the development of Lactobacillus and Bifidobacterium spp. microbiota after caesarean section. Further analysis of potential consequences of these findings is required.     

Commensal Bacteria and MAMPs Are Necessary for Stress-Induced Increases in IL-1β and IL-18 but Not IL-6, IL-10 or MCP-1

Regular interactions between commensal bacteria and the enteric mucosal immune environment are necessary for normal immunity. Alterations of the commensal bacterial communities or mucosal barrier can disrupt immune function. Chronic stress interferes with bacterial community structure (specifically, α-diversity) and the integrity of the intestinal barrier. These interferences can contribute to chronic stress-induced increases in systemic IL-6 and TNF-α. Chronic stress, however, produces many physiological changes that could indirectly influence immune activity. In addition to IL-6 and TNF-α, exposure to acute stressors upregulates a plethora of inflammatory proteins, each having unique synthesis and release mechanisms. We therefore tested the hypothesis that acute stress-induced inflammatory protein responses are dependent on the commensal bacteria, and more specifically, lipopolysaccharide (LPS) shed from Gram-negative intestinal commensal bacteria. We present evidence that both reducing commensal bacteria using antibiotics and neutralizing LPS using endotoxin inhibitor (EI) attenuates increases in some (inflammasome dependent, IL-1 and IL-18), but not all (inflammasome independent, IL-6, IL-10, and MCP-1) inflammatory proteins in the blood of male F344 rats exposed to an acute tail shock stressor. Acute stress did not impact α- or β- diversity measured using 16S rRNA diversity analyses, but selectively reduced the relative abundance of Prevotella. These findings indicate that commensal bacteria contribute to acute stress-induced inflammatory protein responses, and support the presence of LPS-mediated signaling in stress-evoked cytokine and chemokine production. The selectivity of the commensal bacteria in stress-evoked IL-1β and IL-18 responses may implicate the inflammasome in this response.     

Comparison of the Growth and Survival of Larval Turbot in the Absence of Culturable Bacteria with Those in the Presence of Vibrio anguillarum, Vibrio alginolyticus, or a Marine Aeromonas sp

Larval turbot (Scophthalmus maximus) were reared on rotifers (Brachionus plicatilis) in the absence of culturable bacteria for up to 14 days and exhibited growth and high rates of survival (>55% in five experiments). Low numbers of known bacteria were introduced into similar cultures by exposure of the rotifers to a suspension of bacteria prior to addition of rotifers to the larval cultures; Vibrio anguillarum 91079 caused a highly significant decrease (P <0.01) in the proportion of survivors in two separate trials. With an Aeromonas sp. previously isolated from a healthy batch of copepod-fed larvae, there was no significant difference in survival compared with control larvae, even though the density of bacteria in the water of larval cultures reached 10(sup7) ml(sup-1). Bacteria colonized the gut of larvae exposed to Aeromonas-treated rotifers to levels similar to those in conventionally reared fish (>4 x 10(sup4) CFU per larva). Rearing of larvae in the presence of known bacteria provides a means of investigating the interaction of specific bacteria with turbot larvae and could provide a method for the selection of bacteria which may restrict the growth of opportunistic pathogens which would be harmful to turbot larvae.     

Use of 4% Chlorhexidine Detergent Solution (Hibiscrub) and Other Methods of Skin Disinfection

In a comparison of three antiseptic detergent preparations for hand washing, Hibiscrub, a 4% chlorhexidine detergent solution, caused a significantly greater estimated immediate reduction of skin flora (86·7% ± 3·0) than was obtained with Dermofax, a 0·75% chlorhexidine detergent solution (55·5% ± 5·1), or with Disadine scrub, a povidone iodine detergent preparation (68% ± 6·8). After six applications the mean estimated reductions of skin flora were 99·2% ± 0·2 for Hibiscrub, 97·7% ± 0·7 for povidone iodine, and 91·8% ± 1·6 for Dermofax.After a series of hand washings with Hibiscrub, as with a hexachlorophane detergent preparation, a further large reduction of skin flora, shown by bacterial counts of hand sampling, was obtained by a second phase of disinfection consisting of two minutes'' application on gauze swabs of 0·5% chlorhexidine digluconate in 70% ethanol; a further wash with Hibiscrub, in place of alcoholic chlorhexidine, for the second phase of disinfection caused an increase rather than a reduction in the yield of bacteria on skin sampling. Unlike this “two-phase” disinfection, the application for 30 minutes of compresses soaked in 10% aqueous povidone iodine or in 0·5% aqueous chlorhexidine digluconate did not cause a greater reduction in skin flora than that obtained by the conventional two minutes'' application on gauze of 0·5% chlorhexidine in 70% ethanol.Chlorocresol (0·3%) liquid soap (the base used for Ster-Zac liquid hexachlorophane soap) caused a mean reduction of skin flora when used for hand washing of 29% after one application and 72% after six applications spread over two days. This formulation, though less active and more variable as a detergent skin antiseptic than chlorhexidine, hexachlorophane, or povidone iodine detergent preparations, is an inexpensive disinfectant soap which could be useful in catering establishments. Alcoholic cetrimide applied as for disinfection of an operation site caused a reduction of skin flora greater than that shown by aqueous cetrimide but comparable to that shown by 70% ethyl alcohol in previous experiments.     

Cytokine Profiles at Admission Can Be Related to Outcome in AIDS Patients with Cryptococcal Meningitis

Cryptococcal meningitis (CM) remains as common life-threatening AIDS-defining illness mainly in resource-limited settings. Previous reports suggested that baseline cytokine profiles can be associated to fungal burden and clinical outcome. This study aimed to evaluate the baseline cytokine profiles in AIDS patients with CM and its relation with the outcome at weeks 2 and 10. Thirty AIDS patients with CM diagnosed by cerebrospinal fluid (CSF) Cryptococcus neoformans positive culture, India ink stain and cryptococcal antigen test were prospectively evaluated. As controls, 56 HIV-infected patients without CM and 48 non-HIV individuals were included. Baseline CSF and sera levels of IL-2, IL-4, IL-8, IL-10, IL-12p40, IL-17A, INF-γ and TNF-α were measured by ELISA. Of 30 CM patients, 24 (80%) were male, median age of 38.1. The baseline CSF high fungal burden and positive blood culture were associated with a positive CSF culture at week 2 (p = 0.043 and 0.029). Most CSF and sera cytokines presented higher levels in CM patients than control subjects (p < 0.05). CSF levels of IL-8, IL-12p40, IL-17A, TNF-α, INF-γ and sera TNF-α were significantly higher among survivors at weeks 2 and 10 (p < 0.05). Patients with increased intracranial pression exhibited CSF IL-10 high levels and poor outcome at week 10 (p = 0.032). Otherwise, baseline CSF log10 IFN-γ and IL-17A were negatively correlated with fungal burden (r = -0.47 and -0.50; p = 0.0175 and 0.0094, respectively). The mortality rate was 33% (10/30) at week 2 and 57% (17/30) at week 10. The severity of CM and the advanced immunodeficiency at admission were related to a poor outcome in these patients. Otherwise, the predominant Th1 cytokines profile among survivors confirms its pivotal role to infection control and would be a prognostic marker in cryptococcal meningitis.     

Assessment of Regional Ventilation Distribution: Comparison of Vibration Response Imaging (VRI) with Electrical Impedance Tomography (EIT)

Background

Vibration response imaging (VRI) is a bedside technology to monitor ventilation by detecting lung sound vibrations. It is currently unknown whether VRI is able to accurately monitor the local distribution of ventilation within the lungs. We therefore compared VRI to electrical impedance tomography (EIT), an established technique used for the assessment of regional ventilation.

Methodology/Principal Findings

Simultaneous EIT and VRI measurements were performed in the healthy and injured lungs (ALI; induced by saline lavage) at different PEEP levels (0, 5, 10, 15 mbar) in nine piglets. Vibration energy amplitude (VEA) by VRI, and amplitudes of relative impedance changes (rel.ΔZ) by EIT, were evaluated in seven regions of interest (ROIs). To assess the distribution of tidal volume (V_T) by VRI and EIT, absolute values were normalized to the V_T obtained by simultaneous spirometry measurements. Redistribution of ventilation by ALI and PEEP was detected by VRI and EIT. The linear correlation between pooled V_T by VEA and rel.ΔZ was R² = 0.96. Bland-Altman analysis showed a bias of −1.07±24.71 ml and limits of agreement of −49.05 to +47.36 ml. Within the different ROIs, correlations of V_T-distribution by EIT and VRI ranged between R² values of 0.29 and 0.96. ALI and PEEP did not alter the agreement of V_T between VRI and EIT.

Conclusions/Significance

Measurements of regional ventilation distribution by VRI are comparable to those obtained by EIT.     

Comparative, Collaborative, and On-Site Validation of a TaqMan PCR Method as a Tool for Certified Production of Fresh, Campylobacter-Free Chickens

Certified Campylobacter-free poultry products have been produced in Denmark since 2002, the first example of fresh (unprocessed and nonfrozen) chickens labeled “Campylobacter free.” This success occurred partly through use of a 4-hour gel-based PCR testing scheme on fecal swabs. In this study, a faster, real-time PCR approach was validated in comparative and collaborative trials, based on recommendations from the Nordic system for validation of alternative microbiological methods (NordVal). The comparative real-time PCR trial was performed in comparison to two reference culture protocols on naturally contaminated samples (99 shoe covers, 101 cloacal swabs, 102 neck skins from abattoirs, and 100 retail neck skins). Culturing included enrichment in both Bolton and Preston broths followed by isolation on Preston agar and mCCDA. In one or both culture protocols, 169 samples were identified as positive. The comparative trial resulted in relative accuracy, sensitivity, and specificity of 98%, 95%, and 97%, respectively. The collaborative trial included nine laboratories testing neck skin, cloacal swab, and shoe cover samples, spiked with low, medium, and high concentrations of Campylobacter jejuni. Valid results were obtained from six of the participating laboratories. Accuracy for high levels was 100% for neck skin and cloacal swab samples. For low levels, accuracy was 100% and 92% for neck skin and cloacal swab samples, respectively; however, detection in shoe cover samples failed. A second collaborative trial, with an optimized DNA extraction procedure, gave 100% accuracy results for all three spiking levels. Finally, on-site validation at the abattoir on a flock basis was performed on 400 samples. Real-time PCR correctly identified 10 of 20 flocks as positive; thus, the method fulfilled the NordVal validation criteria and has since been implemented at a major abattoir.     

Impact of HIV Infection and Kaposi Sarcoma on Human Herpesvirus-8 Mucosal Replication and Dissemination in Uganda

Introduction

Kaposi sarcoma (KS) is the leading cause of cancer in Uganda and occurs in people with and without HIV. Human herpesvirus-8 (HHV-8) replication is important both in transmission of HHV-8 and progression to KS. We characterized the sites and frequency of HHV-8 detection in Ugandans with and without HIV and KS.

Methods

Participants were enrolled into one of four groups on the basis of HIV and KS status (HIV negative/KS negative, HIV positive/KS negative, HIV negative/KS positive, and HIV positive/KS positive). Participants collected oral swabs daily and clinicians collected oral swabs, anogenital swabs, and plasma samples weekly over 4 weeks. HHV-8 DNA at each site was quantified by polymerase chain reaction (PCR).

Results

78 participants collected a total of 2063 orals swabs and 358 plasma samples. Of these, 428 (21%) oral swabs and 96 (27%) plasma samples had detectable HHV-8 DNA. HHV-8 was detected more frequently in both the oropharynx of persons with KS (24 (57%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p = 0.002) and the peripheral blood (30 (71%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p<0.001). In a multivariate model, HHV-8 viremia was more frequent among men (IRR = 3.3, 95% CI = 1.7–6.2, p<0.001), persons with KS (IRR = 3.9, 95% CI = 1.7–9.0, p = 0.001) and persons with HIV infection (IRR = 1.7, 95% CI = 1.0–2.7, p = 0.03). Importantly, oral HHV-8 detection predicted the subsequent HHV-8 viremia. HHV-8 viremia was significantly more common when HHV-8 DNA was detected from the oropharynx during the week prior than when oral HHV-8 was not detected (RR = 3.3, 95% CI = 1.8–5.9 p<0.001). Genital HHV-8 detection was rare (9 (3%) of 272 swabs).

Conclusions

HHV-8 detection is frequent in the oropharynx and peripheral blood of Ugandans with endemic and epidemic KS. Replication at these sites is highly correlated, and viremia is increased in men and those with HIV. The high incidence of HHV-8 replication at multiple anatomic sites may be an important factor leading to and sustaining the high prevalence of KS in Uganda.     

Early impairment of myocardial deformation assessed by regional speckle-tracking echocardiography in the indeterminate form of Chagas disease without fibrosis detected by cardiac magnetic resonance

Chagas disease (CD) will account for 200,000 cardiovascular deaths worldwide over the next 5 years. Early detection of chronic Chagas cardiomyopathy (CCC) is a challenge. We aimed to test if speckle-tracking echocardiography (STE) can detect incipient myocardial damage in CD. METHODS: Among 325 individuals with positive serological tests, 25 (age 55±12yrs) were selected to compose the group with indeterminate form of Chagas disease (IFCD), based on stringent criteria of being asymptomatic and with normal EKG/X-ray studies. This group was compared with a group of 20 patients with CCC (55±11yrs) and a group of 20 non-infected matched control (NC) subjects (48±10yrs). CD patients and NC were submitted to STE and CD patients were submitted to cardiac magnetic resonance (CMR) with late gadolinium administration to detect cardiac fibrosis by the late enhancement technique. Global longitudinal strain (GLS), circumferential (GCS) and radial strain (GRS) were defined as the average of segments measured from three apical view (GLS) and short axis views (GRS and GCS). Regional left ventricular (LV) longitudinal strain (Reg LS) was measured from each of the 17 segments. Twist was measured as systolic peak difference between basal and apical rotation and indexed to LV length to express torsion. RESULTS: STE global indices (GLS, GCS, twist and torsion) were reduced in CCC vs NC (GLS: -14±6.3% vs -19.3±1.6%, p = 0.001; GCS: -13.6±5.2% vs -17.3 ±2.8%; p = 0.008; twist: 8±7° vs 14±7°, p = 0.01 and torsion: 0.96±1°/cm vs 1.9±1°/cm, p = 0.005), but showed no differences in IFCD vs NC. RegLS was reduced in IFCD vs NC in four LV segments: basal-inferior (-16.3±3.3% vs -18.6±2.2%, p = 0.013), basal inferoseptal (-13.1±3.4 vs -15.2±2.7, p = 0.019), mid-inferoseptal (-17.7±3.2 vs -19.4±2, p = 0.032) and mid-inferolateral (-15.2±3.5 vs -17.8±2.8, p = 0.014). These abnormalities in RegLS occurred in the absence of myocardial fibrosis detectable with CMR in nearly 92% of subjects with IFCD, while myocardial fibrosis was present in 65% with CCC. CONCLUSION: RegLS detects early regional impairment of myocardial strain that is independent from fibrosis in IFCD subjects.