Preoperative oral hygiene treatment reduces bacterial transport and colonization during intubation for orthopedic surgery.

PURPOSE: The process of infection by bacteria and viruses involves invasion, establishment, growth, and parasitization. Poor oral hygiene and dysbiosis are significant risk factors for pneumonia. The aim of this study was to evaluate bacterial transport into the trachea during intubation for orthopedic surgery and the impact of oral hygiene treatment. METHODS: The study cohort included 53 patients with fracture who underwent surgical procedures under general anesthesia and were divided into two groups: an oral hygiene treatment (OHT) group (n = 27) and a control group (n = 26). Before intubation, the OHT group underwent preoperative oral hygiene treatment. Microbiological culture was used for detection and counting of bacteria from the oropharynx, trachea, and tip of the endotracheal tube (ETT). RESULTS: Patients in the OHT group had a lower pathogen detection rate and lower degree of bacterial colonization in the oropharynx, trachea, and ETT tip. CONCLUSION: Preoperative oral hygiene treatment is able to reduce bacterial transport and colonization during orthopedic surgery, thus providing an important adjunct to pre-anesthesia care.

Inflammatory responses and barrier disruption in the trachea of chicks following Mycoplasma gallisepticum infection: a focus on the TNF-α-NF-κB/MLCK pathway.

Mycoplasma gallisepticum (MG) can induce persistent inflammatory damage to the tracheal mucosa of poultry and cause chronic respiratory diseases in chickens. To further investigate the mechanism of MG-induced injury to the tracheal mucosa, we used chick embryo tracheal organ culture (TOC) as a model to study the invasion and reproduction of MG, the effect of MG on tracheal morphology, and the potential factors that promote MG tissue invasion. The results showed that MG infection significantly damaged the tracheal epithelial structure and weakened tracheal epithelial barrier function; MG also increased the occurrence of bacterial displacement, with a significant (p < 0.05) increase in the bacterial load of the infected TOCs at 5 and 7 days post-infection. In addition, MG significantly (p < 0.05) increased the expression levels of inflammatory cytokines, such as TNF-α, interleukin-1ß (IL-1ß), and IL-6, and activated the NF-κB signalling pathway, leading to increased nuclear translocation of NF-κB p65. Simultaneously, the map kinase pathway (MAPK) was activated. This activation might be associated with increased myosin light chain (MLC) phosphorylation, which could lead to actin-myosin contraction and disruption of tight junction (TJ) protein function, potentially compromising epithelial barrier integrity and further catalysing MG migration into tissues. Overall, our results contribute to a better understanding of the interaction between MG and the host, provide insight into the mechanisms of damage to the tracheal mucosa induced by MG infection, and provide new insights into the possible pathways involved in Mycoplasma gallisepticum infection in vivo.

A real-time PCR assay for the quantification of Mycoplasma equirhinis in tracheal wash samples from Thoroughbred horses.

Mycoplasma equirhinis is the predominant equine Mycoplasma sp. isolated from clinically normal horses and is suspected to be associated with inflammatory airway disease in which cough is the primary sign. Quantitative evaluation of bacterial counts is useful in assessing the association between the bacteria in samples and observed clinical signs, but this evaluation has been difficult with conventional culture methods of M. equirhinis given the need for pre-enrichment using liquid cultures. We established a quantitative real-time PCR (qPCR) assay for the quantification of M. equirhinis, targeting the hypothetical protein FJM08_00025. We confirmed its high species-specificity for M. equirhinis and a limit of detection of 2.9 copies/reaction. We quantified M. equirhinis in tracheal wash samples from 20 clinically normal horses and 22 coughing horses. The copy numbers detected by qPCR in 18 of the 22 samples from clinically affected horses were within the range detected in the 20 clinically normal horses (0-84 copies/reaction). The remaining 4 samples had considerably higher copy numbers (734-1,620,000 copies/reaction), suggesting the likely involvement of M. equirhinis infection. Quantitative evaluation of M. equirhinis over time using our qPCR assay may allow a more accurate assessment of M. equirhinis infection in coughing horses compared to culture methods.

Detection of fungi in the airways of horses according to the sample site: a methodological study.

Fungal detection in equine airways may be performed on either tracheal wash (TW) or bronchoalveolar lavage fluid (BALF) by either cytology or culture. However, method comparisons are sparse. Our objective was to determine the prevalence of fungi in airways of horses according to the sample site and laboratory methodology. Sixty-two adult horses, investigated in the field or referred for respiratory disease, were included. Tracheal wash, and BALF collected separately from both lungs, were collected using a videoendoscope. Fungi were detected in cytologic samples examined by light microscopy, and by fungal culture. Hay was sampled in the field. Prevalence of fungi was of 91.9% in TW and 37.1% in BALF. Fungi were cultured from 82.3% of TW and 20.9% of BALF. Fungal elements were observed cytologically in 69.4% of TW and 22.6% of BALF. In 50% of horses, the same fungi were detected in both TW and hay, but fungi detected in BALF and hay differed in all horses. Poor agreement was found for the detection of fungi between TW and BALF and between fungal culture and cytologic examination (Cohen's kappa coefficient (κ) < 0.20). Moderate agreement was found between cytologic examination of left and right lungs (κ = 0.47). The prevalence of fungi detected cytologically on pooled BALF was significantly different (p = 0.023) than on combined left and right BALF. Fungi were more prevalent in the TW than BALF, and results suggest that hay might not be the primary source of fungi of the lower respiratory tract of horses.

Lower airway ultrasonographic, endoscopic, and cytological changes in horses undergoing inhalation anesthesia with controlled ventilation for minor elective surgeries.

Effects of general anesthesia with controlled ventilation on the respiratory system have had limited evaluation in horses. A prospective observational study was performed with eleven client-owned horses undergoing elective surgery. Physical examination, auscultation with a rebreathing bag, complete blood cell count, lung ultrasound imaging, tracheal endoscopy imaging and transendoscopic tracheal wash were conducted before and 24 hours after anesthesia. Lung ultrasound imaging was also repeated just after recovery. A significant increase in blood neutrophil count between pre- and post-anesthesia (P=0.004) was observed. There was an increase in ultrasonographic score of the lungs at recovery (left P=0.007, right P=0.017). The score of the dependent lung was higher than the independent lung at recovery time (P=0.026) but no difference was observed 24 hours after anesthesia. The tracheal mucus score was higher after anesthesia (P=0.001); severe local inflammation was present in several horses at the site of endotracheal tube cuff. Neutrophil count was significantly higher on tracheal wash fluid cytology after anesthesia (P=0.016), without any significant changes on bacterial load. Increased tracheal mucus score and neutrophil count in tracheal wash samples were observed after general anesthesia in healthy horses without clinical evidence of pneumonia (fever, cough). Tracheal inflammation secondary to endotracheal intubation and cuff inflation was, therefore, suspected. Elective surgery without complications can induce inflammation of the trachea and changes in ultrasound images of the lungs in healthy horses and should be considered when evaluating respiratory system after a general anesthesia.

Epidemiology and pathogenicity of M. equirhinis in equine respiratory disorders.

Mycoplasmas are pathogens involved in respiratory disorders of various animal hosts. In horses, Mycoplasma (M.) equirhinis is the species most frequently detected in clinical respiratory specimens, with a prevalence of 12-16%, but its clinical implication in equine respiratory disorders remains unclear. Here we screened 1948 clinical specimens for the presence of M. equirhinis. The samples were both tracheal washes (TW) and bronchoalveolar lavages (BAL) collected by veterinarians in France in day-to-day work between 2020 and 2022. The samples were associated with a standardized form that served to collect key general and clinical information, such as horse age, breed, and living environment. M. equirhinis was detected using a combination of culture and post-enrichment PCR. Other diagnostic data included virology and bacteriology as well as neutrophil counts, when available. Prevalence of M. equirhinis was examined as a function of a clinical score based on four significant clinical signs (nasal discharge, cough, dyspnoea, and hyperthermia). Multivariate logistic regression analysis was run to identify risk factors for the presence of M. equirhinis, and comparative prevalence analysis was used to test for association with other bacteria and viruses. TW and BAL were analysed independently, as we found that TW samples were associated with a higher prevalence of M. equirhinis. As prevalence remained steady whatever the clinical score, M. equirhinis cannot be considered a primary pathogen. M. equirhinis was more frequently isolated in thoroughbreds and trotters and in horses living exclusively stabled compared to other horses or other living environments. M. equirhinis was never detected in BAL specimens with a 'normal' neutrophil count, i.e. 5%, suggesting it could be associated with an inflammatory response, similar to that observed in equine asthma. Prevalence of M. equirhinis was shown to increase in the presence of other bacteria such as Streptococcus equi subsp. zooepidemicus (S. zoo) or viruses, and S. zoo load was higher in M. equirhinis-positive samples, suggesting a potential increase of clinical signs in the event of co-infection.

Detection of Mycoplasma spp. in horses with respiratory disorders.

BACKGROUND: Bacteria belonging to the genus Mycoplasma are small-sized, have no cell walls and small genomes. They commonly cause respiratory disorders in their animal hosts. Three species have been found in the respiratory tract of horses worldwide, that is., Mycoplasma (M.) equirhinis, M. pulmonis and M. felis, but their role in clinical cases remains unclear. OBJECTIVES: The aim of this study was to i) develop and validate tools to detect, isolate and identify different Mycoplasma spp. strains in clinical equine respiratory-tract specimens and ii) subsequently define the prevalence of the three species in France depending on sample types and horse characteristics (age, breed, sex). STUDY DESIGN: Validation of a workflow for mycoplasma diagnosis and subsequent prevalence study. METHODS: Mycoplasma-free tracheal wash samples spiked with numerated strains and DNA dilutions were used to validate the culture methods and real-time PCR (rt-PCR) assay. Isolated strains were identified by 16S rRNA gene sequencing. Prevalences were determined on a population of 616 horses with respiratory disorders, sampled in France in 2020. RESULTS: In total, 104 horses (16.9%) were found to be positive for Mycoplasma spp. by at least one method. M. equirhinis was the predominant circulating species, accounting for 85% of the rt-PCR-positive samples and 98% of the 40 cultured strains. MAIN LIMITATION: The proposed pre-enrichment procedure improves the sensitivity of detection but hinders the quantification of the initial mycoplasma load in the clinical specimens. CONCLUSIONS: Prevalence of mycoplasma varied with age, breed, and type of sample.

Endotracheal Aspirate and Ventilator-Associated Pneumonia in Neonates: Revisiting an Age-Old Debate.

OBJECTIVES: To explore the utility of endotracheal aspirates (ETA) for analyzing microbiological yield, incidence, risk factors for VAP, and clinically relevant outcomes. METHODS: Ventilated neonates suspected to have VAP were studied prospectively; they were classified as "VAP" or "No VAP" based on a predefined combination of clinical, radiological, and laboratory criteria. The microbiological yield from blood and ETA cultures was analyzed. RESULTS: Of 165 neonates who were ventilated for > 48 h, 65 were suspected of having VAP. Thirty-six (22.9%) were classified as VAP. Microbiological agents could be identified in 31 cases (86.1%) by ETA/blood cultures. Acinetobacter sp was the common organism identified. Duration of ventilation, and a higher number of reintubations before suspicion of VAP were significant risk factors for VAP. Positive ETA culture was associated with a greater duration of oxygen therapy and ventilation days after suspicion of VAP. CONCLUSIONS: The commonest culture yield from ETA in those suspected to have VAP was gram-negative bacilli. Duration of ventilation and reintubations were identified as significant risk factors for VAP. These are potentially modifiable factors. Positive ETA culture was associated with longer needs for respiratory supports. Negative ETA culture might encourage clinicians to stop antibiotics. TRIAL REGISTRATION: Clinical Trials Registry of India No. CTRI/2019/03/017912,  www.ctri.nic.in.

Endotracheal lactate reflects lower respiratory tract infections and inflammation in intubated patients.

The aim of this study was to assess L-lactate and D-lactate in endotracheal aspirate from intubated patients hospitalized at the intensive care unit and explore their use as diagnostic biomarkers for inflammation and lower respiratory tract infections (LRTI). Tracheal aspirates from 91 intubated patients were obtained at time of intubation and sent for microbiological analyses, neutrophil count, and colorimetric lactate measurements. We compared the concentration of lactate from patients with microbiological verified LRTI or clinical/radiological suspicion of LRTI with a control group. In addition, associations between inflammation and the lactate isomers were examined by correlating L-lactate and D-lactate with sputum neutrophils and clinical assessments. The concentration of L-lactate was increased in aspirates with verified or suspected LRTI (p < 0.001) relative to the control group at Day 0. Connections between L-lactate and inflammation were indicated by the correlation between neutrophils and L-lactate (p < 0.001). We found no increase in sputum D-lactate from patients with verified or suspected LRTI relative to the control group and D-lactate was not correlated with neutrophils. L-lactate was found to be a potential indicator for inflammation and LRTI at the time of intubation. An association was found between neutrophil count and L-lactate. Interestingly, the increase of L-lactate in the control group after intubation may suggest that intubation challenges the host response by inflicting tissue damage or by introducing infectious microbes.

Airway microbiome dynamics and relationship to ventilator-associated infection in intubated pediatric patients.

BACKGROUND: Little is known about the airway microbiome in intubated mechanically ventilated children. We sought to characterize the airway microbiome longitudinally and in association with clinical variables and possible ventilator-associated infection (VAI). METHODS: Serial tracheal aspirate samples were prospectively obtained from mechanically ventilated subjects under 3 years old from eight pediatric intensive care units in the United States from June 2017 to July 2018. Changes in the tracheal microbiome were analyzed by sequencing bacterial 16S ribosomal RNA gene relative to subject demographics, diagnoses, clinical parameters, outcomes, antibiotic treatment, and the Ventilator-Associated InfectioN (VAIN) score. RESULTS: A total of 221 samples from 58 patients were processed and 197 samples met the >1000 reads criteria (89%), with an average of 43,000 reads per sample. The median number of samples per subject was 3 (interquartile range [IQR]: 2-5), with a median VAIN score of 2 (IQR: 1-3). Proteobacteria was the highest observed phyla throughout the intubation period, followed by Firmicutes and Actinobacteria. Alpha diversity was negatively associated with days of intubation (p = .032) and VAIN score (p = .016). High VAIN scores were associated with a decrease of Mycobacterium obuense, and an increase of Streptococcus peroris, Porphyromonadaceae family (unclassified species), Veillonella atypica, and several other taxa. No specific pattern of microbiome composition related to clinically diagnosed VAIs was observed. CONCLUSIONS: Our data demonstrate decreasing alpha diversity with increasing VAIN score and days of intubation. No specific microbiome pattern was associated with clinically diagnosed VAI.

Association of Endotracheal Aspirate Culture Variability and Antibiotic Use in Mechanically Ventilated Pediatric Patients.

Importance: Endotracheal aspirate cultures are commonly collected from patients with mechanical ventilation to evaluate for ventilator-associated pneumonia or tracheitis. However, the respiratory tract is not sterile, making differentiating between colonization from bacterial infection challenging, and results may be unreliable owing to variable specimen quality and sample processing across laboratories. Despite these limitations, clinicians routinely interpret bacterial growth in endotracheal aspirate cultures as evidence of infection, sometimes regardless of organism significance, prompting antibiotic treatment. Objective: To assess the variability in endotracheal aspirate culture rates and the association between culture rates and antibiotic prescribing among patients with mechanical ventilation across children's hospitals in the US. Design, Setting, and Participants: Cross-sectional retrospective analysis of data obtained from the Children's Hospital Association Pediatric Health Information System database between January 1, 2016, through December 31, 2019. Participants were all patients hospitalized with mechanical ventilation aged less than 18 years. Exposures: A charge for an endotracheal aspirate culture on a ventilated day. Main Outcomes and Measures: Endotracheal aspirate culture rate and antibiotic days of therapy per ventilated days. For mechanical ventilation, clinical transaction classification codes for mechanical ventilation other unspecified ventilator assistance were used. To identify respiratory cultures, the laboratory test code for aerobic culture was used and relevant keywords (ie, respiratory tract, sputum) were used to identify sources in the hospital charge description master. Results: A total of 152 132 patients were identified among 31 hospitals. Among these patients, 79 691 endotracheal aspirate cultures were collected on a ventilator-day (patients aged less than 1 year, 44%; 1-4 years, 27%, 5-11 years. 16%, and 12-18 years, 13%; 3% were Asian; 17% Hispanic; 21% non-Hispanic Black; 45% Non-Hispanic White patients; 14% were other; 56% of patients were male, 44% were female). The overall median rate of culture use was 46 per 1000 ventilator-days (IQR, 32-73 cultures per 1000 ventilator-days). The endotracheal aspirate culture rate was positively correlated with the hospital's antibiotic days of therapy rate (R = 0.46; P = .009). In a multivariable model adjusting for patient-level and hospital-level characteristics and among patients with mechanical ventilation, each additional endotracheal aspirate culture was associated with 2.87 (95% CI, 2.74-3.01) higher odds of receiving additional days of therapy compared with patients who did not receive and endotracheal aspirate culture. Conclusions and Relevance: In this study, notable variability was found in endotracheal aspirate culture rates across US pediatric hospitals and pediatric intensive care units, and endotracheal aspirate culture use was associated with increased antibiotic use. These findings suggest an opportunity for diagnostic and antibiotic stewardship to standardize testing and treatment of suspected ventilator-associated infections in pediatric patients with mechanical ventilation pediatric patients.

Exclusively Tracheobronchial Paracoccidioidomycosis: A Rare Presentation.

Paracoccidioidomycosis (PCM), or blastomycosis in South America, is a systemic granulomatous mycosis related to activities associated with soil management, especially agriculture. PCM restricted to tracheobronchial tree region has not yet been reported.

Corynebacterium zhongnanshanii sp. nov. isolated from trachea of Marmota himalayana, Corynebacterium lujinxingii sp. nov. and Corynebacterium wankanglinii sp. nov. from human faeces.

Six novel facultatively anaerobic, Gram-stain-positive, rod-shaped, non-haemolytic bacteria (zg-320T/zg-336, zg-917T/zg-910 and zg-913T/zg-915) isolated from animal tissues and human faeces were found to belong to the genus Corynebacterium based on the phylogenetic analyses of 16S rRNA gene and 262 core genes set. Based on the greatest degree of 16S rRNA similarity, zg-320T/zg-336 had the highest 16S rRNA gene similarity to Corynebacterium falsenii DSM 44353T (97.51 %), zg-917T/zg-910 to Corynebacterium coyleae DSM 44184T (98.68 %), and zg-913T/zg-915 to Corynebacterium afermentans subsp. lipophilum CIP 103500T (98.79 %). The three novel type strains had a relatively high DNA G+C content (61.2-64.4 mol%), low DNA relatedness and ANI values with their respective neighbours: 23.5/72.7 %, 25.0/72.3%and 22.6/73.1 % (zg-320T vs. Corynebacterium auriscanis CIP 106629T, Corynebacterium resistens DSM 45100T and Corynebacterium suicordis DSM 45110T); 24.4/82.3% and 23.7/81.3 % (zg-917T vs. C. coyleae DSM 44184T and Corynebacterium jeddahense JCBT); 26.8/83.7% and 27.7/84.4 % (zg-913T vs. Corynebacterium mucifaciens ATCC 700355T and C. afermentans subsp. lipophilum CCUG 32105T). The three novel species had C16 : 0, C18 : 0, C18 : 1 ω9c and C18 : 0 ante/C18 : 2 ω6,9c as the major cellular fatty acids; MK-8(H2) in strain zg-917T and MK-9(H2) in strains zg-320T and zg-913T were found to be the major respiratory quinones. For the three novel species, the detected major polar lipids included diphosphatidylglycerol, phosphatidyl inositol mannoside, phosphatidylglycerol and phosphatidylinositol, the cell-wall peptidoglycan was based on meso-DAP, and the whole-cell sugars mainly included ribose, arabinose and galactose. The three novel species grew optimally at 35-37 °C, 0.5 % (w/v) NaCl and pH 7.0-8.0; notably, they were tolerant of 10.5 % (w/v) NaCl. Based on the results of these comprehensive analyses, three novel species in the genus Corynebacterium are proposed, aptly named Corynebacterium zhongnanshanii sp. nov. (zg-320T = GDMCC 1.1719T = JCM 34106T), Corynebacterium lujinxingii sp. nov. (zg-917T = GDMCC 1.1707T = JCM 34094T) and Corynebacterium wankanglinii sp. nov. (zg-913T = GDMCC 1.1706T = JCM 34398T).

An outbreak investigation of Burkholderia cepacia infections related with contaminated chlorhexidine mouthwash solution in a tertiary care center in Turkey.

BACKGROUND: We report a nosocomial outbreak caused by Burkholderia cepacia that occurred among six patients admitted in the medical and surgical intensive care unit between 04 March 2019 and 02 April 2019 in Istanbul, Turkey. METHODS: The outbreak investigation was launched on 11 March 2019 five days after the detection of B. cepacia in four different patients. We defined potential reservoirs and started environmental screening. We sampled the liquid solutions used in patient care activities. Pulse-field gel electrophoresis (PFGE) was performed to determine the genetic relatedness of environmental and patient samples. RESULTS: Burkholderia cepacia was isolated in tracheal aspiration cultures of six patients. Three out of six patients developed healthcare-associated pneumoniae due to B. cepacia. Environmental cultures in the ICUs revealed B. cepacia growth in 2% chlorhexidine-gluconate mouthwash solution that been used in the colonized patients as well as in samples obtained from the unused products. PFGE revealed the patient and a specific batch of chlorhexidine mouthwash solution samples had a 96% similarity. CONCLUSION: Contamination of medical solutions used in critical patient care could cause outbreaks and should be detected early by infection control teams.

Molecular typing and antifungal susceptibility study of Aspergillus spp. in intensive care unit (ICU) patients in Indonesia.

INTRODUCTION: Aspergillus exhibits a wide variation of susceptibility against antifungals according to genetic and environmental factors. Identification to the species level is necessary for appropriate treatment. Our objective was to determine the Aspergillus species involved in invasive pulmonary aspergillosis (IPA) among ICU patients in Jakarta, Indonesia. METHODOLOGY: The incidence of IPA in ICU patients at six hospitals in Jakarta from October 2012 - January 2015 was investigated. It involved a collection of endotracheal aspirates (ETA), nasal swabs and environmental samples around the hospitals, phenotypic screening, molecular characterization, and antifungal susceptibility testing. RESULTS: Of the 405 patients investigated, 31 patients (7.7%) were diagnosed with putative IPA, from whom 45 Aspergillus isolates were collected. Aspergillus isolates were identified from pulmonary secretions in 24 patients, from nasal swabs in 7 patients and from both pulmonary secretions and nasal swabs in 7 patients. The phenotypic method showed 33 isolates of Aspergillus flavus (73.4%), nine Aspergillus fumigatus (20%), two Aspergillus niger (4.4%), and one Aspergillus nidulans (2.2%) isolate. Molecular identification showed 27 isolates of A. flavus (60.0%), eight isolates of A. fumigatus (17.8%), two isolates of A. niger (4.4%) and one isolate of A. nidulans (2.2%), while seven isolates (15.6%) were cryptic species or mixed isolates. CONCLUSIONS: Susceptibility testing showed all isolates were susceptible to amphotericin B, azoles and micafungin. Aspergillus flavus was the main causative organism in IPA cases in Jakarta, followed by A. fumigatus.

Evaluation of GeneXpert PA assay compared to genomic and (semi-)quantitative culture methods for direct detection of Pseudomonas aeruginosa in endotracheal aspirates.

INTRODUCTION: Pseudomonas aeruginosa is a common cause of ventilator-associated pneumonia (VAP). Rapid and accurate detection of lower respiratory tract colonization and/or infection with P. aeruginosa may advise targeted preventive (antibody-based) strategies and antibiotic therapy. To investigate this, we compared semi-quantitative culture results from 80 endotracheal aspirates (ETA) collected from mechanically-ventilated patients, to two culture and two non-culture-based methods for detection of P. aeruginosa. METHODS: P. aeruginosa-positive (n = 40) and -negative (n = 40) ETAs from mechanically ventilated patients analyzed initally by (i) routine semi-quantitative culture, were further analyzed with (ii) quantitative culture on chromogenic ChromID P. aeruginosa and blood agar; (iii) enrichment in brain heart infusion broth followed by plating on blood agar and ChromID P. aeruginosa; (iv) O-antigen acetylase gene-based TaqMan qPCR; and (v) GeneXpert PA PCR assay. RESULTS: Of the 80 ETA samples included, one sample that was negative for P. aeruginosa by semi-quantitative culture was found to be positive by the other four methods, and was included in an "extended" gold standard panel. Based on this extended gold standard, both semi-quantitative culture and the GeneXpert PA assay showed 97.6% sensitivity and 100% specificity. The quantitative culture, enrichment culture and O-antigen acetylase gene-based TaqMan qPCR had a sensitivity of 97.6%, 89.5%, 92.7%, and a specificity of 97.4%, 100%, and 71.1%, respectively. CONCLUSION: This first evaluation of the GeneXpert PA assay with ETA samples found it to be as sensitive and specific as the routine, hospital-based semi-quantitative culture method. Additionally, the GeneXpert PA assay is easy to perform (hands-on time ≈ 5 min) and rapid (≈ 55 min assay time). The combination of the high sensitivity and high specificity together with the rapid acquisition of results makes the GeneXpert PA assay a highly recommended screening technique. Where this equipment is not available, semi-quantitative culture remains the most sensitive of the culture methods evaluated here for P. aeruginosa detection in ETA samples.

Endobronchial lipoma with tracheobronchial aspergillosis: A case report.

INTRODUCTION: Benign neoplasm of the endobronchial tree is quite rare, while endobronchial lipoma is extremely rare. Tracheobronchial aspergillosis is a relatively uncommon but severe form of invasive aspergillosis involving the tracheobronchial tree. PATIENT CONCERNS: A 54-year-old male presented to our hospital for investigation and treatment of a cough and hemoptysis. DIAGNOSIS: The diagnosis was confirmed as endobronchial lipoma with tracheobronchial aspergillosis. INTERVENTIONS: The patient received pneumonectomy and voriconazole treatment. OUTCOMES: The patient's postoperative course was uneventful, and he was discharged 10 days after surgery. The patient had no evidence of the fungal infection and recurrence during 1 year of follow-up. CONCLUSION: Endobronchial lipoma is a rare benign lung tumor, and this is the first report of endobronchial lipoma with tracheobronchial aspergillosis. In patients with suspected endobronchial lipoma, especially those who present with hemoptysis as the initial symptom, it is advisable to exclude coexistent aspergillosis.

The alterations of tracheal microbiota and inflammation caused by different levels of ammonia exposure in broiler chickens.

Ammonia (NH3) is a known harmful gas and exists in haze, forming secondary organic aerosols. Exposure to ambient ammonia correlates with the respiratory tract infection, and microbiota in the upper respiratory tract is an emerging crucial player in the homeostatic regulation of respiratory tract infection, and microbiota perturbation is usually accompanied by the inflammatory reactions; however, the effects of different levels of ammonia exposure on tracheal microbiota and inflammation are unclear. A total of 288 22-day-old male Arbor Acres broilers were chosen and divided into 4 groups with 6 replicates of 12 chickens, and respectively exposed to ammonia at 0, 15, 25, and 35 ppm for 21-d trial period. Cytokines (interleukin (IL)-1ß, IL-6, and IL-10) in the trachea were measured at the 21 d of exposure to NH3. Tracheal microbiota at the 21 d was analyzed by the 16S rRNA gene analysis. The results showed that an increase in ammonia levels, even in 15 ppm, significantly decreased the alpha diversity and changed the bacterial community structure. Six genera (Faecalibacterium, Ruminococcus]_torques_group, unclassified_f__Lachnospiraceae, Ruminococcaceae_UCG-014, Streptococcus, Blautia) significantly increased, whereas Lactobacillus significantly decreased under different levels of ammonia exposure. We also observed positive associations of Faecalibacterium, Blautia, g__Ruminococcaceae_UCG-014, unclassified_f__Lachnospiraceae and Ruminococcus]_torques_group abundances with tracheal IL-1ß concentration. Moreover, an increase in ammonia levels, even in 15 ppm, caused respiratory tract inflammatory injury. The results indicated that 15 ppm ammonia exposure changed the composition of tracheal microbiota that caused the tracheal injury possibly through increasing the IL-1ß, which might make the broiler more sensitive to the changes of environment and pathogenic micro-organisms in the poultry house, and may be also a critical value that needs high alertness. Herein, the present experiment also suggested that the standard limit of ammonia concentration in adult poultry house is 15 ppm. This research provides an insight into the relationship between the upper respiratory tract microbiota and inflammation under ammonia exposure.

Proteolytic cleavage of HLA class II by human neutrophil elastase in pneumococcal pneumonia.

Bacterial and viral respiratory infections can initiate acute lung injury and acute respiratory distress syndrome. Neutrophils and their granule enzymes, including neutrophil elastase, are key mediators of the pathophysiology of acute respiratory failure. Although intracellular neutrophil elastase functions as a host defensive factor against pathogens, its leakage into airway spaces induces degradation of host connective tissue components. This leakage disrupts host innate immune responses via proteolytic cleavage of Toll-like receptors and cytokines. Here, we investigated whether neutrophils possess proteases that cleave adaptive immune molecules. We found that expression of the human leukocyte antigen (HLA) class II molecule HLA-DP ß1 was decreased in THP-1-derived macrophages treated with supernatants from dead neutrophils. This decreased HLA-DP ß1 expression was counteracted by treatment with neutrophil elastase inhibitor, suggesting proteolytic cleavage of HLA-DP ß1 by neutrophil elastase. SDS-PAGE showed that neutrophil elastase cleaved recombinant HLA-DP α1, -DP ß1, -DQ α1, -DQ ß1, -DR α, and -DR ß1. Neutrophil elastase also cleaved HLA-DP ß1 on extracellular vesicles isolated from macrophages without triggering morphological changes. Thus, leakage of neutrophil elastase may disrupt innate immune responses, antigen presentation, and T cell activation. Additionally, inhibition of neutrophil elastase is a potential therapeutic option for treating bacterial and viral pneumonia.