Tracheal Aspirates Research Articles

Multi Drug Resistance Pseudomonas Aeruginosa Frequency and Antibiogram in A Tertiary Teaching Care Hospital in Pakistan

Antibiotic usage and misuse increases the risk of developing bacteria that are resistant to treatment. A Gram-negative, aerobic bacillus called Pseudomonas aeruginosa is mostly responsible for nosocomial opportunistic infections. Objectives: To assess pathogen load and drug susceptibility profiles of Peshawar clinical specimens collected with MDR Pseudomonas aeruginosa isolates. Methods: Isolates were gathered from a variety of specimens, including pus, tracheal aspirate, swabs containing wound samples, fluids such as urine or blood, from department of microbiology hospital of Khyber teaching Peshawar. Clinical in-vitro study which were carried out at the Pharmacology Department, University of Peshawar. Kirby Bauer Disc diffusion method was used to identify the pattern of antibiotic susceptibility. Requirements of Clinical and Laboratory Standards Institute (2018) were followed for processing samples. Results: P. aeruginosa was found to be multidrug-resistant in about 56 percent of cases. The majority of the isolates (36.5%) were found in people between the ages of "60-80". Pus included the greatest percentage of MDR P. aeruginosa (34.2%), followed by tracheal aspiration (21.7 percent). Colistin had the highest sensitivity (100%) and was followed by ceftolozane/tazobactam (61 percent). With imipenem, the least sensitivity was noticed (20 percent). However, all anti-pseudomonal medications showed an increase in resistance. Conclusion: In our system, MDR P. aeruginosa infections are becoming more frequent. This threat can be avoided by prescribing antibiotics carefully. For the community to receive appropriate healthcare, regular lab identification and surveillance of this resistant pathogen is necessary

Tracheostomized children tracheal colonization and antibiotic resistance profile – A STROBE analysis

AimsTo verify the prevalence of Potentially pathogenic bacteria (PPB) and their antimicrobial resistance profile in tracheal aspirates of children with tracheostomy and compare it to clinical data. MethodsA cross-sectional study was conducted in patients aged 0–18 years who all underwent tracheostomy cannula change (TCC) performed by the Otolaryngology Unit at Hospital de Clínicas de Porto Alegre, Brazil, between October, 2017 and December, 2018. Patients were submitted, at the time of TCC, to a tracheal aspirate through the tracheostomy and secretion was sent to microbiological analysis and antimicrobial susceptibility testing. Clinical data were evaluated through available patients’ electronic medical records. ResultsForty-four patients had their tracheostomy aspirate cultured and all but one presented PPB growth (97.7%). Median age was 3 years-old. Pseudomonas aeruginosa was the most prevalent bacteria (56.9%) and it was resistant to gentamycin, amikacin and cefepime in 36%, 28% and 12% of the culture tests, respectively. P. aeruginosa resistance to gentamycin and to cefepime suggested an association with the number of antibiotic classes used in the 12 months before enrollment (both p=0.04) and with 2 or more hospital admissions in the same period (p=0.03 and p=0.02, respectively). Staphylococcus aureus was isolated in 9.1% and there was no MRSA. ConclusionIt was found a 97.7% prevalence of PPB in the cultured aspirates; the most prevalent bacterium was P. aeruginosa and there was no MRSA identification. Data suggest an association between P. aeruginosa antimicrobial resistance with previous use of antibiotic therapy.

Bond Spreads and CDS-Bond Basis: Impact of Dodd-Frank Title VII

The tracheal isolation of Ureaplasma urealyticum from critically ill infants was investigated to determine if the organism was associated with an inflammatory response. Twenty nine neonates consecutively admitted for acute respiratory disease, with birthweights of < 1301 g and no evidence of viral, chlamydial, or bacterial infections, were identified. Culture results for ureaplasmas were correlated with white cell counts and clinical and radiographic features. Sixteen infants had tracheal aspirates and/or blood specimens positive for U urealyticum. Pneumonia was diagnosed more frequently in the U urealyticum positive infants than in the 13 who were negative for the organism. The mean total white cell count, absolute neutrophil, and band form counts were significantly higher in the U urealyticum positive group than in the negative group. These data suggest that U urealyticum can induce an inflammatory response in selected individuals who present with clinical, radiographic, and, in some instances, histological features of pneumonia.

Antibiotic Susceptibility of Microorganisms Grown in Tracheal Aspirate Cultures of Pediatric Intensive Care Patients.

BackgroundMicroorganisms proliferating in the hospital setting cause infections with high morbidity and mortality rates. In intensive care units (ICUs), the rates of antibiotic resistance and microorganisms grown in cultures may vary by time period. Antibiotic sensitivity must be known for a correct empirical treatment approach. This study aimed to investigate the distribution and antibiotic resistance profiles of pathogenic microorganisms isolated from tracheal aspirate samples in the ICU.MethodologyThis study enrolled 100 tracheostomized patients aged one month to 18 years, regardless of gender, who were followed in the ICU of Dicle University for more than 72 hours. Medical data were retrospectively evaluated from the medical records. Care was taken to collect samples before changing antibiotics. Antibiotherapy was continued until after culture antibiogram results were obtained, or empirical antibiotic therapy was started by giving consideration to the potential source in patients with a suspected infection.ResultsAn analysis of the tracheal aspirate culture samples of the patients showed that Pseudomonas aeruginosa (54%), Acinetobacter baumannii (16%), and Staphylococcus aureus (8%) were the most common pathogens. An analysis of the culture antibiogram results of the tracheal aspirate samples obtained from the entire study population showed that P. aeruginosa was 100% resistant against vancomycin, clindamycin, and teicoplanin, but highly sensitive to colistin and amikacin. A. baumannii was highly resistant to almost all antibiotics but showed no resistance against colistin. Carbapenems being frequently preferred for cases where empirical therapy should be initiated for ICU infections can be one of the reasons for a high carbapenem resistance rate in our hospital.ConclusionsWe believe that starting empirical therapy with colistin when infections caused by Pseudomonas and Acinetobacter are suspected may be an appropriate initial therapy until culture antibiogram results become available. Microbiological data are crucial for a correct empirical treatment approach. In this way, intensive antibiotic usage and subsequent high antibiotic resistance can be adequately controlled.

Acetylcholine, Fatty Acids, and Lipid Mediators Are Linked to COVID-19 Severity.

Lipid and cholinergic mediators are inflammatory regulators, but their role in the immunopathology of COVID-19 is still unclear. Here, we used human blood and tracheal aspirate (TA) to investigate whether acetylcholine (Ach), fatty acids (FAs), and their derived lipid mediators (LMs) are associated with COVID-19 severity. First, we analyzed the perturbation profile induced by SARS-CoV-2 infection in the transcriptional profile of genes related to the ACh and FA/LM pathways. Blood and TA were used for metabolomic and lipidomic analyses and for quantification of leukocytes, cytokines, and ACh. Differential expression and coexpression gene network data revealed a unique transcriptional profile associated with ACh and FA/LM production, release, and cellular signaling. Transcriptomic data were corroborated by laboratory findings: SARS-CoV-2 infection increased plasma and TA levels of arachidonic acid, 5-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid, 11-hydroxy-5Z,8Z,12E,14Z-eicosatetraenoic acid, and ACh. TA samples also exhibited high levels of PGE2, thromboxane B2, 12-oxo-5Z,8Z,10E,14Z-eicosatetraenoic acid, and 6-trans-leukotriene B4 Bioinformatics and experimental approaches demonstrated robust correlation between transcriptional profile in Ach and FA/LM pathways and parameters of severe COVID-19. As expected, the increased neutrophil-to-lymphocyte ratio, neutrophil counts, and cytokine levels (IL-6, IL-10, IL-1β, and IL-8) correlated with worse clinical scores. Glucocorticoids protected severe and critical patients and correlated with reduced Ach levels in plasma and TA samples. We demonstrated that pulmonary and systemic hyperinflammation in severe COVID-19 are associated with high levels of Ach and FA/LM. Glucocorticoids favored the survival of patients with severe/critical disease, and this effect was associated with a reduction in ACh levels.

"CAPA in Progress": A New Real-Life Approach for the Management of Critically Ill COVID-19 Patients.

(1) Background: COVID-19-associated pulmonary aspergillosis (CAPA) has worsened the prognosis of patients with pneumonia and acute respiratory distress syndrome admitted to the intensive care unit (ICU). The lack of specific diagnosis criteria is an obstacle to the timely initiation of appropriate antifungal therapy. Tracheal aspirate (TA) has been employed under special pandemic conditions. Galactomannan (GM) antigens are released during active fungal growth. (2) Methods: We proposed the term “CAPA in progress” (CAPA-IP) for diagnosis at an earlier stage by GM testing on TA in a specific population admitted to ICU presenting with clinical deterioration. A GM threshold ≥0.5 was set as the mycological inclusion criterion. This was followed by a pre-emptive short-course antifungal. (3) Results: We prospectively enrolled 200 ICU patients with COVID-19. Of these, 164 patients (82%) initially required invasive mechanical ventilation and GM was tested in TA in 93 patients. A subset of 19 patients (11.5%) fulfilled the CAPA-IP criteria at a median of 9 days after ICU admittance. The median GM value was 3.25 ± 2.82. CAPA-IP cases showed significantly higher ICU mortality [52.6% (10/19) vs. 34.5% (50/145), p = 0.036], as well as a much longer median ICU stay than those with a normal GM index [27 (7–64) vs. 11 (9–81) days, p = 0.008]. All cases were treated with a pre-emptive systemic antifungal for a median time of 19 (3–39) days. (4) Conclusions: CAPA-IP highlights a new real-life early approach in the field of fungal stewardship in ICU programs.

Cord blood antimicrobial peptide LL37 levels in preterm neonates and association with preterm complications

BackgroundCathelicidin/LL-37 plays a significant role in the human immune defense reaction. Preterm human immature organs being exposed to inflammation-induced injury was the critical denominator leading to the common preterm associated complications. Previous study showed LL37 concentration in preterm neonates was lower in tracheal aspirates and breast milk as compared to term infants. An adults study showed decreased LL-37 levels was a risk factor for patients in developing severe chronic obstructive pulmonary disease (COPD). However, little is known about the regulation of human cord blood LL37 in preterm neonates and the association with preterm complications. This study was designed to investigate the concentration of LL37 in cord blood of preterm infants and correlation with preterm complications.MethodsSingleton infants born in June 2017 to August 2021 in the study hospital were enrolled. Maternal and neonatal clinical characteristics were collected. LL37 levels, pro-inflammatory factor interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) in cord blood and LL37 levels in serum 48–72 hours after birth were measured by enzyme-linked immunosorbent assay. The serum level of LL37 in preterm and term neonates were compared, the perinatal factors possibly affecting the LL37 levels were investigated and the relationship between LL37 level and preterm outcomes were analyzed.ResultsCord blood LL37 levels in preterm infants were lower than that in term neonates. Cord blood LL37 level was positively correlated with gestational age in preterm. Prenatal steroid administration in preterm neonates decreased cord blood LL37 level. LL37 level was obviously lower in patients with bronchopulmonary dysplasia (BPD). Multiple line regression analysis showed higher LL37 level in cord blood was an independent protective factor for BPD. The concentration of pro-inflammatory factor IL-6 was negatively correlated with LL37.ConclusionCord blood LL37 levels increased during gestation and decreased after perinatal steroid usage. Very preterm infants who displayed higher cord blood LL37 level had reduced risk of developing BPD. Regulation of pro-inflammatory cytokine IL-6 may be associated with the protective effect of LL37 on BPD.

TRAIL protects the immature lung from hyperoxic injury

The hyperoxia-induced pro-inflammatory response and tissue damage constitute pivotal steps leading to bronchopulmonary dysplasia (BPD) in the immature lung. The pro-inflammatory cytokines are considered attractive candidates for a directed intervention but the complex interplay between inflammatory and developmental signaling pathways requires a comprehensive evaluation before introduction into clinical trials as studied here for the death inducing ligand TRAIL. At birth and during prolonged exposure to oxygen and mechanical ventilation, levels of TRAIL were lower in tracheal aspirates of preterm infants <29 weeks of gestation which developed moderate/severe BPD. These findings were reproduced in the newborn mouse model of hyperoxic injury. The loss of TRAIL was associated with increased inflammation, apoptosis induction and more pronounced lung structural simplification after hyperoxia exposure for 7 days while activation of NFκB signaling during exposure to hyperoxia was abrogated. Pretreatment with recombinant TRAIL rescued the developmental distortions in precision cut lung slices of both wildtype and TRAIL−/− mice exposed to hyperoxia. Of importance, TRAIL preserved alveolar type II cells, mesenchymal progenitor cells and vascular endothelial cells. In the situation of TRAIL depletion, our data ascribe oxygen toxicity a more injurious impact on structural lung development. These data are not surprising taking into account the diverse functions of TRAIL and its stimulatory effects on NFκB signaling as central driver of survival and development. TRAIL exerts a protective role in the immature lung as observed for the death inducing ligand TNF-α before.

Bacteriological profile of Tracheal aspirate and their Antimicrobial Sensitivity Pattern in a Tertiary Care Hospital in Dhaka city

Background: The majority of nosocomial infections are seen in intensive care units and they course with higher rates of mortality and morbidity worldwide. Objectives: To identify the current microbial isolates and their antimicrobial susceptibility pattern from the tracheal aspirate culture in a tertiary care hospital in Dhaka city.Materials and Method: This retrospective study was conducted in the department of Microbiology at Holy Family Red Crescent Medical College Hospital, Dhaka from January 2020 to June 2021 for a period of one and a half years. Written consent was taken from the corresponding authority.A total of 109 samples were collected from tracheal aspirates of the patients who were admitted to the hospital with the critically ill patients in intensive care units.Microsoft Excel software was used for data analysis.Results: A total of 109 samples were analyzed. Of them, the predominant populations were male 73(66.97%) and the remaining were female 36(33.03%). Out of 109 samples, 70 (64.22%)was culture positive. Culture negative was 39 (35.78%). The majority of isolates were Gram-negative bacteria. Among them, predominant bacteria wereKlebsiella spp. 43(61.43%) followed by Acinetobacter spp 19(27.15%), Pseudomonas spp. 05(07.14%) &amp; Gram-positive isolates waswereaph. Aureus 03(04.28%). Klebsiella species showed higher sensitivity totigecycline 97.67%, colistin 93.02%, amikacin 65.11% and meropenem 37.20% &amp; gentamicin 30.23%. Other drugs showed wer sensitivity to axicillin/clavulenic acid 18.60%, and ciprofloxacin 18.60% , trimethoprim/ sulfamethoxazole 09.30%, ceftazidime &amp; cefuroxime 04.65% and lowest sensitivity shown in ceftriaxone 02.32%. Acinetobacter speciesshowed higher sensitivityin colistin at 100% and tigecycline at 47.36%. Other drugs like amikacinand trimethoprim/ sulfamethoxazole 15.78% and the lowest sensitivity were shown in meropenem 10.52% and high resistance in gentamycin, ceftriaxone, ceftazidime, and ciprofloxacin.Pseudomonas spp. showed the highest sensitivity 60.00% to piperacillin-tazobactam, amikacin, imipenem, meropenem, and gentamycin, 40.00% to ciprofloxacin, 20.00% to ceftazidime &amp; cefepime.All the isolate of Staph. aureus was the highest sensitive 100% to vancomycin and linezolid, 66.66% sensitive to amikacin, trimethoprim/ sulfamethoxazole, tetracycline, and gentamicin, 33.33% showed lower sensitivityto amoxicillin/ clavulanic acid, cloxacillin and ciprofloxacin.Conclusion:This study aimed to investigate thedistribution of pathogenic microorganisms isolated from tracheal aspirate and their antibiotic sensitivity profile in intensive care units. A periodic review of the bacteriological profile and antibiotic sensitivity pattern is highly essential for the clinician to treat critically ill patients in ICU. Antibiotic policy &amp; infection control programs should be included in every hospital to reduce this drug resistance.

Staphylococcus aureus Alpha-Toxin in Deep Tracheal Aspirates-Preliminary Evidence for Its Presence in the Lungs of Sepsis Patients.

The pore forming alpha-toxin (hemolysin A, Hla) of Staphylococcus aureus (S. aureus) is a major virulence factor with relevance for the pathogenicity of this bacterium, which is involved in many cases of pneumonia and sepsis in humans. Until now, the presence of Hla in the body fluids of potentially infected humans could only be shown indirectly, e.g., by the presence of antibodies against Hla in serum samples or by hemolysis testing on blood agar plates of bacterial culture supernatants of the clinical isolates. In addition, nothing was known about the concentrations of Hla actually reached in the body fluids of the infected hosts. Western blot analyses on 36 samples of deep tracheal aspirates (DTA) isolated from 22 hospitalized sepsis patients using primary antibodies against different epitopes of the Hla molecule resulted in the identification of six samples from five patients containing monomeric Hla (approx. 33 kDa). Two of these samples showed also signals at the molecular mass of heptameric Hla (232 kDa). Semiquantitative analyses of the samples revealed that the concentrations of monomeric Hla ranged from 16 to 3200 ng/mL. This is, to our knowledge, the first study directly showing the presence of S. aureus Hla in samples of airway surface liquid in human patients.

Microbiological analysis of tracheostomy tube biofilms and antibiotic resistance profiles of potentially pathogenic microorganisms

&lt;b&gt;Introduction:&lt;/b&gt; In hospitalized patients, tracheostomy tubes (TTs) are susceptible to colonization by biofilm- producing potentially pathogenic microorganisms (PPMs). Contact with TTs, which are situated in a critical region of the body with enormous microbial exposure, may lead to the emer-gence of resistant respiratory infections.&lt;/br&gt;&lt;/br&gt; &lt;b&gt;Objective:&lt;/b&gt; Our study aimed to isolate and identify Gram-positive and Gram-negative PPMs, mark their antibiotic resistance and determine the bacteriological pattern of the biofilm colonizing the TTs. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Methods:&lt;/b&gt; The study was conducted on 45 tracheostomy tubes obtained from 45 hospitalized adult patients with tracheostomy with intubation periods ranging from 1 to 28 days. Tracheal aspirates (TA) obtained from polyvinyl chloride (PVC) TTs were used for the analysis. Bacteria in biofilms were identified by standard microbiological techniques, tested for antibiotic resistance and phenotypic resistance according to the EUCAST guidelines and visualized by SEM.&lt;/br&gt;&lt;/br&gt; &lt;b&gt;Results:&lt;/b&gt; Out of 45 TTs, 100% were found to be positive in bacterial cultures with 58 PPM isolates (10 spe-cies) correlating well with the SEM findings. Overall, 72% of isolates were Gram-negative bacilli, followed by Gram-positive cocci (28%). Staphylococcus aureus was the predominant bacterium (identified in 35.5% of patients), followed by Klebsiella pneumoniae (identified in 23.8%). Among the Gram-negative PPMs, 50% of isolates were identified as multidrug-resistant (MDR), 8.6% as extremely drug-resistant (XDR) and 5.2% were pandrug-resistant (PDR).&lt;/br&gt;&lt;/br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Our study showed a rapid colonization of the TT surface by biofilm- producing PPMs. Patients with tracheosto- mies, also those with non-infectious conditions, were mainly colonized with highly re-sistant bacteria.

Prevalence of ESBL in Klebsiella Sp. and Its Antibiotic Resistance Pattern from Various Clinical Samples in a Tertiary Care Hospital

Background: Klebsiella infection presents a global medical challenge because it is an important opportunistic GNB in health care institutions. The isolation and identification of resistance pattern of Klebsiella infections helps in selection of appropriate antibiotics, reducing the morbidity and mortality of patients and reducing the spread of resistant strains in the community&#x0D; Objective: The present study was carried out to investigate the prevalence of ESBL in Klebsiella species and its antibiotic resistance pattern from various clinical samples.&#x0D; Method: Specimens like urine, blood, sputum, pus, wound swab, tracheal aspirates&#x0D; Microbes from urine, blood, sputum, pus, wound swab, and tracheal aspirates after preparation and cultivation, and isolation were identified by Gram’s staining and various biochemical reactions. Antibiotic susceptibility testing was done including third generation cephalosporins and the resistant were done by Double disc synergy test (DDST) and Combined disc diffusion test (CDDT).&#x0D; Result: Klebsiella pneumoniae subsp. aerogenes (48%) was the most common species isolated followed by Klebsiella oxytoca (46%), Klebsiella pneumoniae subsp pneumoniae (6%). Among 100 isolates of Klebsiella spp., 53(53%) isolates were ESBL producers. Of the 53(53%) ESBL isolates, 46(46%) isolates showed ESBL production by double disk synergy test and 51(51%) by combined disk diffusion test.&#x0D; Conclusion: Most of Klebsiella ESBL positive isolates were observed in pus sample. Combined disc diffusion test demonstrated more effectivity than double disc diffusion test. So, CDDT being simple and cheaper method should be included in the microbiology laboratories as a routine test for early deduction of ESBL producing organisms in specimen from critically ill patients.

Bacterial and fungal communities in tracheal aspirates of intubated COVID-19 patients: a pilot study

Co-infections with bacterial or fungal pathogens could be associated with severity and outcome of disease in COVID-19 patients. We, therefore, used a 16S and ITS-based sequencing approach to assess the biomass and composition of the bacterial and fungal communities in endotracheal aspirates of intubated COVID-19 patients. Our method combines information on bacterial and fungal biomass with community profiling, anticipating the likelihood of a co-infection is higher with (1) a high bacterial and/or fungal biomass combined with (2) predominance of potentially pathogenic microorganisms. We tested our methods on 42 samples from 30 patients. We observed a clear association between microbial outgrowth (high biomass) and predominance of individual microbial species. Outgrowth of pathogens was in line with the selective pressure of antibiotics received by the patient. We conclude that our approach may help to monitor the presence and predominance of pathogens and therefore the likelihood of co-infections in ventilated patients, which ultimately, may help to guide treatment.

VIM, NDM, IMP, GES, SPM, GIM, SIM Metallobetalactamases in Carbapenem-Resistant Pseudomonas aeruginosa Isolates from a Turkish University Hospital

Background: Pseudomonas aeruginosa is an important opportunistic pathogen, and carbapenem resistance is an emerging problem. The determination of resistance genes is vital for epidemiological purposes, and the early determination of carbapenemase production methods is also recommended. Objectives: The present study aimed to investigate the presence of VIM, NDM, IMP, GES, SPM, GIM, and SIM genes in P. aeruginosa isolates. Methods: In this study, 200 carbapenem-resistant P. aeruginosa isolates were included. The DNA extraction of the carbapenem-resistant isolates was performed using the boiling method. Following the DNA extraction, optimization was conducted using the original primers. After optimization, the VIM, NDM, IMP, GES, SPM, GIM, and SIM genes were examined using the polymerase chain reaction (PCR) method. Results: The isolates were mainly identified from the tracheal aspirate cultures (34.5%). The PCR method revealed the presence of VIM in one of the P. aeruginosa isolates, and the NDM gene in one isolate using. None of the isolates was positive in terms of the IMP, GES, SPM, GIM, and SIM genes. Conclusions: In our study, two carbapenemase genes (VIM and NDM) were detected in the P. aeruginosa isolates.

Timeline Kinetics of Systemic and Airway Immune Mediator Storm for Comprehensive Analysis of Disease Outcome in Critically Ill COVID-19 Patients.

In the present study, the levels of serum and airway soluble chemokines, pro-inflammatory/regulatory cytokines, and growth factors were quantified in critically ill COVID-19 patients (total n=286) at distinct time points (D0, D2-6, D7, D8-13 and D>14-36) upon Intensive Care Unit (ICU) admission. Augmented levels of soluble mediators were observed in serum from COVID-19 patients who progress to death. An opposite profile was observed in tracheal aspirate samples, indicating that systemic and airway microenvironment diverge in their inflammatory milieu. While a bimodal distribution was observed in the serum samples, a unimodal peak around D7 was found for most soluble mediators in tracheal aspirate samples. Systems biology tools further demonstrated that COVID-19 display distinct eccentric soluble mediator networks as compared to controls, with opposite profiles in serum and tracheal aspirates. Regardless the systemic-compartmentalized microenvironment, networks from patients progressing to death were linked to a pro-inflammatory/growth factor-rich, highly integrated center. Conversely, patients evolving to discharge exhibited networks of weak central architecture, with lower number of neighborhood connections and clusters of pro-inflammatory and regulatory cytokines. All in all, this investigation with robust sample size landed a comprehensive snapshot of the systemic and local divergencies composed of distinct immune responses driven by SARS-CoV-2 early on severe COVID-19.

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.

Investigation of the value of precipitins in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients with a positive marker for Aspergillus species.

Although a high prevalence of COVID-19-associated pulmonary aspergillosis has been reported, it is still difficult to distinguish between colonization with Aspergillus fumigatus and infection. Concomitantly, similarities between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and hypersensitivity pneumonitis were suggested. The objective of this study was to investigate retrospectively if precipitin assays targeting A. fumigatus could have been useful in the management of SARS-CoV-2 patients hospitalized in an Intensive Care Unit (ICU) in 2020. SARS-CoV-2 ICU patients were screened for Aspergillus co-infection using biomarkers (galactomannan antigen, qPCR) and culture of respiratory samples (tracheal aspirates and bronchoalveolar lavage). For all these patients, clinical data, ICU characteristics and microbial results were collected. Electrosyneresis assays were performed using commercial A. fumigatus somatic and metabolic antigens. ELISA were performed using in-house A. fumigatus purified antigen and recombinant antigens.Our study population consisted of 65 predominantly male patients, with a median ICU stay of 22 days, and a global survival rate of 62%. Thirty-five patients had at least one positive marker for Aspergillus species detection. The number of arcs obtained by electrosyneresis using the somatic A. fumigatus antigen was significantly higher for these 35 SARS-CoV-2 ICU patients (P 0.01, Welch's t-test). Our study showed that SARS-CoV-2 ICU patients with a positive marker for Aspergillus species detection more often presented precipitins towards A. fumigatus. Serology assays could be an additional tool to assess the clinical relevance of the Aspergillus species in respiratory samples of SARS-CoV-2 ICU patients.Lay SummaryThis study showed retrospectively that precipitin assays, such as electrosyneresis, could be helpful to distinguish between colonization and infection with Aspergillus fumigatus during the management of severe acute respiratory syndrome Coronavirus-2 (SARS CoV-2) patients in an intensive care unit.

Antimicrobial Effect of Syzygium cumini Extract Against Methicillin Non-Susceptible Staphylococcus aureus

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of infections in Community- Associated (CA) as well as Hospital-Associated (HA) settings. Identification of new antibacterial agents from natural sources takes the forefront in research. Objectives: The aim of the present study was to identify the resistance pattern of S. aureus in the clinical samples causing disease in Dhaka city, molecular typing of the methicillin non-susceptible S. aureus isolates and identifying new herbal components with anti-microbial effect against S. aureus. Methods: We screened total of 78 clinical specimen of various nature (pus, urine, tracheal aspirate, conjunctiva and wound swab) with confirm S. aureus infection between March 2018 to October 2018. The specimen were cultured on mannitol salt agar to isolate S. aurues, which were later tested for antibiotic resistance according to disc diffusion method. The MRSA isolates were confirmed with PCR and typed for SCCmec element to know the distribution of hospital-associated and community-associated strains. Finally, the MRSA isolates were cultured in the presence of leaf extract and fruit extract of Syzygium cumini for observing the antibacterial potential. Result: A total of 12 isolates of S. aureus were found to be non-susceptible to methicillin, 34%, 25%, 17% out of these were from pus, blood and urine respectively and 8% isolates were from wound swab, conjunctiva and tracheal aspirates each. Out of methicillin non-susceptible isolates, 25% and 16% were HA-MRSA and CAMRSA respectively, as seen from PCR analysis of the SCCmec gene cassette of the S. aureus genome. The rest of the 59% of the isolates were untypable. Overall, higher concentration of leaf and fruit extract reduced the optical density of MRSA culture and reduced bacterial growth in drop plate significantly. Conclusion: Dhaka population has S. aureus with varying sensitivity against methicillin, which needs further characterization by molecular epidemiology methods. Bangladesh Med Res Counc Bull 2021; 47(1): 82-89

Validation of nasal tracheal aspiration in children with lung disease

BackgroundNasal tracheal aspiration (NTA) is a frequently used diagnostic method to assess of infections in the lower airways. However, the validity of the method has not previously been compared to bronchoalveolar lavage (BAL) in non-intubated children with a lung disease. We hypothesised that NTA performed by health professionals using the nares vocal cord distance to be placed at the entrance of the trachea, will result in same finding of bacteria in the lower airways as the gold standard of BAL.MethodsIn a prospective study, 173 paired samples of NTA and BAL were obtained between June 2016 to August 2018. Samples were collected from all patients undergoing bronchoscopy with spontaneous breathing during general anaesthesia. This study compares the microbiological results from the cultures obtained by investigating complete concordance i.e. identical pathogenic bacteria and coherence i.e. absence or presence of pathogenic bacteria growth between NTA and BAL.ResultsSamples were collected in 164 patients, 158 children between 21 days and 18 years of age and six young adults still treated at the paediatric department. The overall similarity (complete agreement) was found in 49% [41–56], sensitivity was 35% [27–45], specificity was 66% [55–76], positive predictive value was 36% [27–46] and negative predictive value was 64% [54–64] concerning complete pathogenic bacteria concordance. If we only considered coherence growth of pathogenic bacteria, similarity was 71% [63–79], sensitivity was 74% [64–81], specificity was 66% [55–76], positive predictive value was 75% [65–82] and negative predictive value was 65% [54–75]. Patients with cystic fibrosis showed a similarity of 88% [73–95], a sensitivity of 92% [76–99], a specificity of 71% [36–95], a positive predictive value of 92% [76–99] and a negative predictive value of 71% [36–95] concerning coherence growth of pathogenic bacteria.ConclusionThe study indicates that NTA compared to BAL as the gold standard is not clinically useful to assess positive findings of specific bacteria in the lower airway tract. Statistically significantly increased sensitivity and positive predictive value were found in cystic fibrosis patients concerning coherence growth. The clinical usage of NTA remains important as negative findings are of clinical value. However, BAL continues to be preferred as a significantly superior diagnostic tool.

The Airway Microbiome and Metabolome in Preterm Infants: Potential Biomarkers of Bronchopulmonary Dysplasia.

ObjectivesWe investigated the genomic and metabolic characteristics of the airway microbiome in mild, moderate, severe, and non-bronchopulmonary dysplasia (BPD) preterm infants and explored possible mechanisms underlying BPD.MethodsTwenty-eight preterm infants with gestational age ≤34 weeks and intubated within 24 h after birth were enrolled. According to the severity of BPD, the patients were divided into mild, moderate and severe BPD groups, and the non-BPD group was the control group. Tracheal aspirates (TA) were obtained at intubation and on day 7 after birth. The bacterium in the aspirates were sequenced by 16S rRNA, and the metabolomics of the aspirates were identified by high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-Q-TOF/MS). The correlation between the differential metabolite and differential bacteria was investigated using Pearson’s correlation coefficient corrected for gestational age and birth weight and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases.ResultsThere were significant differences in the diversity and composition of airway microbiome and metabolome between severe, moderate and mild BPD and non-BPD premature infants. At birth (day 1), the difference was more pronounced than at day 7. The diversity of airway microbial community decreased, the abundance of Stenotrophomonas increased, and the increased level of sn-glycerol 3-phosphoethanolamine was positively correlated with the severity of BPD. There was a significant positive correlation between the abundance of Stenotrophomonas and the level of sn-glycerol 3-phosphoethanolamine.ConclusionDecreased diversity of the airway microbiome, increased abundance of Stenotrophomonas, and increased level of sn-glycerol 3-phosphoethanolamine may have potential as biomarkers for BPD. The occurrence and severity of BPD are closely related to Stenotrophomonas, which may influence the composition of the lower airway microbiome through its metabolite sn-glycerol 3-phosphoethanolamine, and may be the triggering factor of the disease. The causal relationship needs further study.