Normal Respiratory Flora Research Articles

Pathogenic bacteria in bronchoalveolar lavage cultures and pediatric laryngotracheal reconstruction outcomes.

The primary objective was to determine if treating pathogenic bacteria in bronchoalveolar lavage (BAL) cultures improves outcomes after pediatric double stage laryngotracheal reconstruction (dsLTR). Case series with chart review. Tertiary children's hospital. All children (<18 years) obtaining flexible bronchoscopy with BAL cultures before dsLTR between 2016 and 2022 were included. Cultures identified abnormal bacterial growth or normal respiratory flora. Thirty-day postoperative surgical site or lung infections were captured and tracheostomy decannulation rates were obtained for children with at least 12 months of follow-up. Twenty-seven children obtained presurgical BAL cultures before dsLTR. Median age at reconstruction was 2.9 years (interquartile range: 2.3-3.5) and 89% (24/27) had high grade subglottic stenosis. Positive cultures were obtained in 56% of children (N = 15) with Pseudomonas aeruginosa (40%, 6/15) and methicillin-resistant Staphylococcus aureus (33%, 5/15) the most frequent organisms. All children with positive cultures were treated based on culture and sensitivity data. Postoperative infections developed in 22% (6/27) of children with equal distribution of surgical site and respiratory infections among children with pathogenic bacteria and normal respiratory flora. At 12 months after surgery, the decannulation rate was no different between those treated and not treated for a presurgical positive BAL culture (47% vs. 58%, p = 0.70). Pathogenic bacteria are common in BAL cultures from tracheostomy-dependent children before dsLTR. Treatment keeps respiratory infections and decannulation rates similar to children with negative cultures, suggesting continued benefit of flexible bronchoscopy and BAL in preparation for these surgeries.

INTERSTITIAL LUNG DISEASE EXACERBATED BY NON-NOVEL SARS-COV-2

INTERSTITIAL LUNG DISEASE EXACERBATED BY NON-NOVEL SARS-COV-2

Prosthetic Joint Infection Due to Cardiobacterium hominis: Report of First Known Case and Review of C. hominis Septic Arthritis Literature

Introduction. The Cardiobacterium species is a pleomorphic Gram-negative bacterium discovered in 1964 and is part of the HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella) group of organisms known to cause endocarditis. It has low virulence and can also cause dacryocystitis, septicemia and abdominal abscess. We report a patient with C. hominis prosthetic joint infection in the absence of definitive endocarditis. Case Report. A 57-year-old man presented to his orthopedic surgeon 17 months after left total knee arthroplasty with a 4–5-day history of left knee pain following yard work. He had an aortic valve replacement in 2003, mitral valve repair in 2006 and bovine aortic valve replacement in 2019 (12 months previously). Aspirate of knee joint fluid was grossly cloudy. Two of two preoperative blood cultures revealed Cardiobacterium species after 4 days’ incubation. He was initially treated with intravenous vancomycin plus piperacillin/tazobactam followed by 6 weeks of parenteral ceftriaxone followed by five months of oral cefdinir. Patient is infection-free 6 months after completion of antimicrobial therapy. Discussion. Cardiobacterium hominis is a slow-growing, fastidious, capnophilic, Gram-negative bacillus commonly found in normal oral and upper respiratory flora. Google Scholar™ and PubMed®searches were conducted and this is the first reported case of prosthetic joint infection due to Cardiobacterium hominis. We found three previously reported cases of C. hominis pyogenic arthritis: one patient with native knee pyogenic arthritis, one patient with cervical spondylodiscitis and one patient with lumbar spondylodiscitis and epidural abscess. Two of these three patients had TEE-documented infective endocarditis and one had a bioprosthetic aortic valve without evident vegetation on TEE. Our patient had a bioprosthetic aortic valve without TEE evidence of endocarditis. C. hominis should be added to the list of organisms that can cause bacteremically spread prosthetic joint infection.

The Microbial Etiology of Community-Acquired Pneumonia in Adults: from Classical Bacteriology to Host Transcriptional Signatures.

All modern advances notwithstanding, pneumonia remains a common infection with substantial morbidity and mortality. Understanding of the etiology of pneumonia continues to evolve as new techniques enable identification of already known organisms and as new organisms emerge. We now review the etiology of pneumonia (at present often called "community-acquired pneumonia") beginning with classic bacteriologic techniques, which identified Streptococcus pneumoniae as the overwhelmingly common cause, to more modern bacteriologic studies, which emphasize Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Enterobacteriaceae, Pseudomonas, and normal respiratory flora. Urine antigen detection is useful in identifying Legionella and pneumococcus. The low yield of bacteria in recent studies is due to the failure to obtain valid sputum samples before antibiotics are administered. The use of high-quality sputum specimens enables identification of recognized ("typical") bacterial pathogens as well as a role for commensal bacteria ("normal respiratory flora"). Nucleic acid amplification technology for viruses has revolutionized diagnosis, showing the importance of viral pneumonia leading to hospitalization with or without coinfecting bacterial organisms. Quantitative PCR study of sputum is in its early stages of application, but regular detection of high counts of bacterial DNA from organisms that are not seen on Gram stain or grown in quantitative culture presents a therapeutic dilemma. This finding may reflect the host microbiome of the respiratory tract, in which case treatment may not need to be given for them. Finally, host transcriptional signatures might enable clinicians to distinguish between viral and bacterial pneumonia, an important practical consideration.

A CASE OF NON-RESOLVING PNEUMONIA

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: Non-resolving pneumonia is defined as pneumonia with slow or incomplete resolution despite adequate appropriate antibiotic treatment. It is a common reason for pulmonary consultations & bronchoscopies in the hospital. Though occurrence is relatively rare, there are many reasons non-resolving pneumonia may develop. Often, they are caused by resistant organisms, mechanical airway obstructions, inappropriate antibiotic treatment, & inadequate duration of treatment. We present a rare case of non-resolving pneumonia, which led to irreversible respiratory failure. CASE PRESENTATION: A 68-year-old male with no significant past medical history presented with worsening dyspnea on exertion & cough productive of yellowish sputum for 5 weeks. In the ER, he reported fevers, night sweats, & unintentional 10-lb weight loss. Vitals showed tachycardia & hypoxia. Physical exam was positive for decreased breath sounds on the right with rhonchi. The patient had not seen a physician for many years. He reported smoking 1 pack per day for 50 years. Chest X-ray showed extensive opacification of the right hemithorax with a small pleural effusion, which suggested multi-lobar right lung pneumonia. The patient was started on empiric piperacillin-tazobactam & vancomycin. Sputum culture grew normal respiratory flora. Blood cultures remained negative. Extensive infectious workup was performed with all tests being negative. CTPA revealed airspace opacities within the right lung & fluid density within the right lung apex which is consistent with early lung necrosis. Bronchoscopy showed a normal bronchial tree. Bronchoalveolar lavage cytology showed no malignant cells. After 10 days of no clinical improvement, a repeat CT chest showed worsening right lung opacification, ground-glass opacities within the left upper lobe, & enlarged mediastinal lymph nodes. The patient continued to worsen clinically therefore underwent right limited thoracotomy & lung biopsy, which showed extensive adhesions with pleural & lung implants. Pathology revealed lung adenocarcinoma. The patient declined therapeutic chemotherapy treatment & opted to go home with hospice. DISCUSSION: This case emphasizes the importance of early recognition of non-resolving pneumonia, the proper diagnostic approach, & when to initiate further invasive workup. Evaluation of a patient with a slowly or incompletely resolved pneumonia starts with a careful history, physical examination, & review of the medical record CONCLUSIONS: Consideration of risk factors for delayed resolution should include age, comorbidities, the severity of pneumonia, & specific pathogens. If indicated, further evaluation should include CT chest to assess for findings suggestive of an alternative diagnosis. When pneumonia fails to resolve, bronchoscopy should be considered. Patients with a negative bronchoscopy examination should undergo further evaluation with lung biopsy to assess for malignancy REFERENCE #1: Jameson, J. L., Kasper, D. L., Longo, D. L., Fauci, A. S., Hauser, S. L., & Loscalzo, J. (2018). Harrison's principles of internal medicine. New York: McGraw-Hill Education. DISCLOSURES: No relevant relationships by Luqman Baloch, source=Web Response No relevant relationships by Luqman Baloch, source=Web Response No relevant relationships by Adrienne DaGue, source=Web Response No relevant relationships by ayobami olaleye, source=Web Response

Candida species in community-acquired pneumonia in patients with chronic aspiration

BackgroundWhen Candida species is found in a sputum culture, clinicians generally dismiss it as a contaminant. We sought to identify cases of community-acquired pneumonia (CAP) in which Candida might play a contributory etiologic role.MethodsIn a convenience sample of patients hospitalized for CAP, we screened for “high-quality sputum” by Gram stain (> 20 WBC/epithelial cell) and performed quantitative sputum cultures. Criteria for a potential etiologic role for Candida included the observation of large numbers of yeast forms on Gram stain, intracellular organisms and > 106 CFU/ml Candida in sputum. We gathered clinical information on cases that met these criteria for possible Candida infection.ResultsSputum from 6 of 154 consecutive CAP patients had large numbers of extra- and intracellular yeast forms on Gram stain, with > 106 CFU/ml Candida albicans, glabrata, or tropicalis on quantitative culture. In all 6 patients, the clinical diagnoses at admission included chronic aspiration. Greater than 105 CFU/ml of a recognized bacterial pathogen (Streptococcus pneumoniae, Staphylococcus aureus, or Pseudomonas) or > 106 CFU/ml of other ‘normal respiratory flora’ (Lactobacillus species) were present together with Candida spp. in every case. Blood cultures yielded Candida in 2 cases, and 1,3-beta-D glucan was > 500 ng/mL in 3 of 3 cases in which it was assayed. Since all patients were treated with anti-bacterial and anti-fungal drugs, no inference about etiology can be derived from therapeutic response.ConclusionsCandida spp. together with a recognized bacterial pathogen or normal respiratory flora may contribute to the cause of CAP in patients who chronically aspirate.

A bacterial and fungal profile of sputum samples in a tertiary care hospital in Puducherry

The microscopic examination of gram stained sputum sample aids in diagnosis of patients with lower respiratory tract infections. Gram stain plays the key role in deciding the appropriateness of the quality of the sputum sample received in the laboratory for culture. It helps to determine the represent ativeness of the sample for the site of collection intended. This study was done to correlate gram stain findings with culture and to assess the use of Gram stain in sputum examination in diagnostic microbiology. During 2017 (July to December) a total of 133 sputum samples were quality assessed using Bartlett’s grading system. The total scoring was done and sample showing score of 1 and above were cultured and identified based on colony characteristics, gram staining morphology and biochemical reactions. One hundred and thirty-three sputum samples were collected from patients with suspected lower respiratory tract infection. Of the 133 samples, 110(79%) were accepted and 23 (21%) were found to be unacceptable by Bartlett criteria. Potential pathogens were grown in 84 samples in the acceptable category. Normal respiratory flora were grown in 26 samples. Out of 84 samples, 63 samples were positive for bacterial growth and 21 showed fungal growth. Out of 63 bacterial growth, 44 were from in-patients and 19 were from out-patients. Among these bacterial isolates, 23 isolates were followed by 16 isolates were , 10 isolates were , 6 isolates were Staphylococcus aureus, 2 isolates were species, 3 isolates were and 3 isolates were Serratia marcesens. All the sputum samples should be subjected to gram staining before culture to differentiate true pathogens from contaminating flora on culture.

Incidence of multidrug-resistant bacteria in tracheal secretions from critically ill patients in the intensive care unit

Abstract Ventilator-associated pneumonia is a severe nosocomial infection that affects the disease course of critically ill patients. Awareness of potential pathogens is essential for prevention, early detection, and proper treatment, as well. In this retrospective cross-sectional study, we investigated the tracheal secretions collected from critically ill patients with the aim to detect the occurrence of multidrug-resistant bacteria. We examined the bacteriological culture results of the tracheal secretions of the patients hospitalized at the Intensive Care Unit of Tîrgu Mureș Emergency Clinical County Hospital between 1st November 2017 and 31st January 2018. Admission diagnoses and comorbidities were recorded, and white blood cell counts were monitored. We determined the quality of the lower respiratory samples by microscopic examination and the results of the microbiological tests, taking into account the germ count of pathogens and the antibiotic-resistance pheno-type. During the three months, 194 samples were received from 107 patients for bacteriological examination. After the first sample collection 34 (31.77%) tracheal secretions were positive for pathogens, while in the remaining samples normal upper respiratory bacterial flora was found. From the 34 positive samples, 22 were colonizing pathogens and 30 were isolated in a clinically significant amount. Predominantly Staphylococcus aureus (n=14; 26.9%), Klebsiella pneumoniae (n=9; 17.3%), Escherichia coli (n=8.1%) and other Gram-negative bacteria (n=21; 40.4%) were identified. Among these strains 38 (73.07%) were not multidrug-resistant. The rate of positivity of individual sampling showed a positive correlation with the average duration of hospital stay (p=0.0016; r=0.8740). A total of 26 patients developed early-onset or late-onset ventilator-associated pneumonia. Potential risk factors for infection with multidrug-resistant bacteria were found. We can conclude that recently admitted patients in the intensive care unit are rarely carriers of multidrug-resistant bacteria, but become colonized or infected with multidrug-resistant strains during long-term intensive care.

Normal Respiratory Flora as a Cause of Community-Acquired Pneumonia.

BackgroundIntensive studies have failed to identify an etiologic agent in >50% cases of community-acquired pneumonia (CAP). Bacterial pneumonia follows aspiration of recognized bacterial pathogens (RBPs) such as Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus after they have colonize the nasopharynx. We hypothesized that aspiration of normal respiratory flora (NRF) might also cause CAP.MethodsWe studied 120 patients hospitalized for CAP who provided a high-quality sputum specimen at, or soon after admission, using Gram stain, quantitative sputum culture, bacterial speciation by matrix-assisted laser desorption ionization time-of-flight, and viral polymerase chain reaction. Thresholds for diagnosis of bacterial infection were ≥105 colony-forming units (cfu)/mL sputum for RBPs and ≥106 cfu for NRF.ResultsRecognized bacterial pathogens were found in 68 of 120 (56.7%) patients; 14 (20.1%) of these had a coinfecting respiratory virus. Normal respiratory flora were found in 31 (25.8%) patients; 10 (32.2%) had a coinfecting respiratory virus. Infection by ≥2 RBPs occurred in 10 cases and by NRF together with RBPs in 13 cases. Among NRF, organisms identified as Streptococcus mitis, which share many genetic features of S pneumoniae, predominated. A respiratory virus alone was found in 16 of 120 (13.3%) patients. Overall, an etiologic diagnosis was established in 95.8% of cases.ConclusionsNormal respiratory flora, with or without viral coinfection, appear to have caused one quarter of cases of CAP and may have played a contributory role in an additional 10.8% of cases caused by RBPs. An etiology for CAP was identified in >95% of patients who provided a high-quality sputum at, or soon after, the time of admission.

Bacterial colonisation of the endotracheal tube in ventilated very preterm neonates: A retrospective cohort study.

To determine the rate, type and timing of bacterial endotracheal tube (ETT) colonisation in neonates born <32 weeks gestational age (GA); and if bacterial colonisation is associated with chronic lung disease (CLD), septicaemia, length-of-stay or mortality. All intubated newborns born <32 weeks GA were included. Endotracheal aspirates were routinely obtained three times-per-week. Cohort was divided into three colonisation groups: no growth, normal respiratory flora only, significant bacteria. Logistic regression was performed to identify if ETT bacterial colonisation was associated with CLD, septicaemia or mortality. A general linear model was fitted for length-of-stay. ETT aspirates were sent from 1054 infants: no growth n = 319, only normal respiratory flora n = 357, and significant bacteria n = 378. ETTs became colonised in 70%, most in the first week of life (82%). Most grew normal respiratory flora (642 infants). In those with significant bacteria, 40% grew Gram-negative species; Klebsiella in 34%. Staphylococcus aureus grew in 104 patients. Adjusted odds ratios for CLD (43% of cohort) compared with no growth were, for normal respiratory flora, 0.58 (95% confidence interval (CI) 0.34-0.99) and, for significant bacteria, 0.48 (95% CI 0.24-0.93). With no overall association between colonisation group and CLD in the adjusted model P = 0.07. The odds of septicaemia (10% of cohort) were 4.50 (95% CI 1.98-10.23, P < 0.001) times greater for significant bacteria compared with no growth. No significant associated was found with mortality or length-of-stay. Bacterial colonisation of ETTs is common. It is associated with more septicaemia. There was no significant association with CLD, longer admission or mortality.

Characterization of Experimental and Clinical Bioaerosol Generation During Potential Aerosol-Generating Procedures

BackgroundDuring medical procedures with the potential to produce aerosols such as bronchoscopy, intubation, or CPR, health-care workers (HCWs) may be exposed to infectious bioaerosols. This scenario is of particular concern when high consequence pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are circulating. Thousands of HCWs have been infected with SARS-CoV-2. However, the determinants of aerosol generation during medical procedures and their relative risk to HCWs remain poorly characterized.Research QuestionThe goal of this study was to characterize aerosols produced during airway intubation by using an uninfected translational animal model and in human subjects undergoing elective aerosol-generating procedures. The study also determined the particle size distribution of generated particles.Study Design and MethodsAerosol generation was measured during highly controlled experimental (pig) intubations (N = 16) and elective bronchoscopies in uninfected patients (N = 49) using an optical particle counter. Recovery of normal respiratory flora was used as a surrogate for pathogen dispersion.ResultsThere was a small but significant (P = .03) decrease in 0.3 μm size particles during highly controlled pig intubations compared with baseline. The concentration of 1.0 μm and 5.0 μm aerosol particles did not significantly change, although oral bacteria were collected from the air. For elective patient bronchoscopies, there was a significant decrease in the generation of larger particles (1.0 μm and 5.0 μm) compared with baseline (P < .01); however, 18 of 39 (46%) patients showed increased aerosol production in 0.3 μm size particles, four of whom exhibited measurable increases.InterpretationAlthough the total amount of aerosols produced during intubation and bronchoscopy did not increase significantly relative to preprocedural levels, a small number of participants exhibited a measurable increase in submicron particle emission, meriting further research to delineate determinants of fine particle production during aerosol-generating procedures.

PREVELANCE OF ORAL AND RESPIRATORY MICROORGANISMS ON THE CAD-CAM VERSUS PRESS FORM OF POLY-ETHER-ETHER KETONE MATERIAL FOR ORAL AND MAXILLOFACIAL PROSTHESIS

INTRODUCTION: Biofilm formation differs in accordance to material type and processing technique, which has a crucial impact on maxillofacial prosthetic materials’ practicability. OBJECTIVES: to compare the prevalence of the upper respiratory tract and oral microbial flora colonization on the two commercially available forms of polyetheretherketone (modified PEEK); the conventional press form and the CAD-CAM form. MATERIALS AND METHODS: : forty eight circular discs, were processed forming four groups: Group I: twelve BioHPP discs were prepared with CAD-CAM form, Group II: twelve BioHPP discs with conventional press form, Group III: twelve heat polymerized poly methyl meth acrylate (PMMA) to mimic the polished surface Group IV: twelve heat cured PMMA to mimic the fitting surface. Microbiological procedures were performed including microbiological sampling, isolation, purification and identification, biofilm formation and assessment of the normal oral and respiratory flora on modified PEEK and PMMA discs. RESULTS: Acrylic resin fitting surface group had the highest biofilm formation when compared with the three other groups. No statistical significant difference was found between each pair of the three remaining groups, CAD-CAM BioHPP group showed the lowest biofilm formation of all groups according to mathematical data, but it didn’t approach the level of being statistically significant. CONCLUSIONS: Both BioHPP processing techniques were positive for biofilm formation, though BioHPP CAD-CAM showed a rougher surface than pressed BioHPP, it showed the least biofilm formation of all groups. Fitting surface of acrylic resin group showed the worst results for biofilm formation

2199. The Etiology of Community-Acquired Pneumonia with Attention to the Role of Normal Respiratory Flora

BackgroundIntensive studies have failed to identify an etiologic agent in >50% of patients (patients) who are hospitalized for community-acquired pneumonia (CAP). Gram stain and culture of sputum samples frequently yield “normal respiratory flora” (NRF). We hypothesized that careful study might (1) increase the yield of recognized pathogens; and (2) show, in some patients, an etiologic role for NRF.MethodsWe studied a convenience sample of adults hospitalized for CAP at a VA Medical Center if they met four criteria: (1) clinical syndrome consistent with pneumonia; (2) newly recognized pulmonary infiltrate; (3) sputum with > 10 WBC per epithelial cell; and (4) < 18 hours antibiotic treatment. For quantification of bacteria, sputum was liquefied in 2% N-acetyl cysteine and diluted serially. Other studies in nearly all patients included blood cultures, urine for pneumococcal (Spn) and Legionella antigen, procalcitonin, B-natriuretic protein and PCR for 13 respiratory viruses, Mycoplasma and Chlamydia. >106 bacteria/mL and a consistent Gram stain indicated a bacterial cause, positive viral PCR indicated a viral cause, and both indicated coinfection.Results119 patients met study criteria. Recognized bacterial pathogens alone were identified in 47 (40%) cases led by Spn 17 (14%), Haemophilus 17 (14%) and S. aureus 6 (5%). A virus alone was identified in 17 (15%) and coinfection in 11 (9%). We applied these same criteria for NRF. NRF alone were found in 22 (19%) patients with S. mitis predominating. NRF and a respiratory virus were coinfecting in 10 (8%) patients. In total, with the inclusion of NRF, an etiologic agent was found in 95% of patients.ConclusionOur high yield is attributable to selection criteria. With a good-quality sputum and absent prolonged antibiotics, a bacterial cause for CAP was found in 59% of patients, a viral cause in 15%, and coinfection in 17%. Bacterial CAP due to recognized pathogen follows microaspiration of colonizing bacteria from the upper airways. Aspiration of a sufficient inoculum of so-called NRF, especially in older adults or those with damaged clearance mechanisms, might well do the same. Careful microbiologic study of patients who are able to provide a valid sputum sample before prolonged antibiotics enables a microbiologic diagnosis in nearly all cases and shows a potential etiologic role for NRF in about 20%. Disclosures All authors: No reported disclosures.

718. Viral Coinfection and Nasal Cytokines in Children with Acute Bacterial Sinusitis (ABS)

BackgroundABS is one of the most common infections in childhood leading to antibiotic prescriptions, but remains a clinical diagnosis. Laboratory testing does not aid diagnosis and there are no predictors to identify those who will respond to therapy or develop complications. Thus, the tools to diagnose and manage ABS remain limited. Initial viral infection predisposes to development of ABS. However, there is poor understanding of the contribution of viral infection to pathogenesis, rate of complications, or the immune response to ABS. The objective of this study was to define bacterial upper airway colonization, viral co-infection and cytokine response in the upper airway during ABS.MethodsIn the context of an ongoing larger prospective clinical study, children were enrolled who were diagnosed with ABS using standardized clinical criteria. Nasopharyngeal (NP) samples were processed for bacterial culture for S. pneumoniae, H. influenzae, S. pyogenes and M. catarrhalis; real-time PCR viral testing and cytokine measurement by qPCR. We correlated these findings with clinical symptoms at the time of presentation.ResultsOf 184 enrolled children (median age 4.9 years), 134 (72.8%) had a positive bacterial culture for potentially pathogenic bacteria and 50 (27.2%) had growth of normal flora. A total of 129 (70.4%) subjects tested positive for a virus. The most common virus detected was rhinovirus (n = 86) followed by influenza virus (n = 23) and adenovirus (n = 21). A total of 102 patients (70.4%) had both a positive pathogenic bacterial culture and viral detection. Patients who had a bacterial pathogen plus a viral detection had a significantly higher expression of IL-6, IL-8 and IL-25 (P < 0.001). Univariable analysis found no correlation between clinical presentation with viral and/or cytokine expressions.ConclusionChildren meeting clinical criteria for ABS and a NP swab with a pathogenic bacteria plus viral detection demonstrated higher expression of inflammatory cytokines compared with subjects whose culture had normal respiratory flora.Disclosures J. V. Williams, Quidel: Board Member, Consulting fee. GlaxoSmithKline: Consultant, Consulting fee.

Corynebacteria as a cause of pulmonary infection: a case series and literature review

BackgroundIn most cases of community-acquired pneumonia (CAP), an etiologic agent is not determined; the most common report from the microbiological evaluation of sputum cites “normal respiratory flora.” Non-diphtheria Corynebacterium spp., a component of this flora, is commonly viewed as a contaminant, but it may be the cause of pneumonia and the frequency with which it causes CAP may be underestimated.Case presentationsThis report present 3 cases of CAP in which Corynebacterium spp. was clearly the predominant isolate; identification was confirmed by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Two cases were caused by C. propinquum and one by C. striatum. Two patients had a tracheostomy and one was on hemodialysis. Patients who received an appropriate antibiotic responded well.ConclusionWhen identified as the predominant isolate in sputum from a patient with CAP, Corynebacterium spp. should be considered as a potential cause of the infection. In cases with patients who have compromised airway clearance or who are immunocompromised, microaspiration may be responsible. While some Corynebacterium spp. are suspectible to antibiotics usually prescribed for CAP, others are susceptible only to vancomycin or aminoglycosides. Vancomycin is thus the appropriate empiric antibiotic, pending speciation and susceptibility test results. The number of reported cases with result of antibiotic susceptibility testing, however, remains limited, and further investigation is needed. Non-diphtheria Corynebacterium spp. represent a noteworthy clinical cause of pneumonia. Identification by Gram stain and as a predominant organism on culture demands careful consideration for management.

Late-onset bleb-associated endophthalmitis and continuous positive airway pressure

PurposeTo raise awareness of a possible association between continuous positive airway pressure (CPAP) devices and postoperative bleb-related infection. ObservationsA 57-year old patient on CPAP presented with unilateral bleb-associated endophthalmitis 32 months after routine ExPress Trabeculectomy with mitomycin C. The offending organism, Streptococcus mitis, is a nonmotile and generally non-virulent pathogen which predominates in the normal human respiratory flora. Conclusions and importanceThis conceptual report underscores a potential relationship between CPAP use and bleb-associated endophthalmitis. Streptococcal species are the most commonly reported causative organisms in bleb-associated endophthalmitis, and S. mitis is of particular concern as the most abundant microbe among all human oral flora. A logical risk factor for infection, the CPAP device may inadvertently deliver such organisms to the vulnerable conjunctival filtering bleb.

Low Efficacy of Antibiotics Against Staphylococcus aureus Airway Colonization in Ventilated Patients.

Airway-colonization by Staphylococcus aureus predisposes to the development of ventilator-associated tracheobronchitis (VAT) and ventilator-associated pneumonia (VAP). Despite extensive antibiotic treatment of intensive care unit patients, limited data are available on the efficacy of antibiotics on bacterial airway colonization and/or prevention of infections. Therefore, microbiologic responses to antibiotic treatment were evaluated in ventilated patients. Results of semiquantitative analyses of S. aureus burden in serial endotracheal-aspirate (ETA) samples and VAT/VAP diagnosis were correlated to antibiotic treatment. Minimum inhibitory concentrations of relevant antibiotics using serially collected isolates were evaluated. Forty-eight mechanically ventilated patients who were S. aureus positive by ETA samples and treated with relevant antibiotics for at least 2 consecutive days were included in the study. Vancomycin failed to reduce methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) burden in the airways. Oxacillin was ineffective for MSSA colonization in approximately 30% of the patients, and responders were typically coadministered additional antibiotics. Despite antibiotic exposure, 15 of the 39 patients (approximately 38%) colonized only by S. aureus and treated with appropriate antibiotic for at least 2 days still progressed to VAP. Importantly, no change in antibiotic susceptibility of S. aureus isolates was observed during treatment. Staphylococcus aureus colonization levels inversely correlated with the presence of normal respiratory flora. Antibiotic treatment is ineffective in reducing S. aureus colonization in the lower airways and preventing VAT or VAP. Staphylococcus aureus is in competition for colonization with the normal respiratory flora. To improve patient outcomes, alternatives to antibiotics are urgently needed.

Factors Associated With Infectious Laryngitis: A Retrospective Review of 15 Cases.

To identify the culturable microbes associated with infectious laryngitis and outline effective treatment strategies. This is a retrospective chart review of adult patients with persistent dysphonia plus evidence of laryngeal inflammation who underwent biopsy for culture at a tertiary care medical center. Demographic factors, symptoms as reported on validated patient assessment tools, past medical history, social history, culture results, and treatment duration and response were reviewed. Fifteen patients with infectious laryngitis were included in this study. Culture results demonstrated Methicillin-sensitive Staphylococcus aureus (MSSA), Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Serratia marcescens, and "normal respiratory flora." In most patients, multiple courses of prolonged antibiotics were needed to treat MSSA or MRSA. Infections associated with other microbes resolved with a single course of antibiotics. In this population, infectious laryngitis is defined as colonization with bacteria not found in the previously characterized laryngeal microbiome of benign vocal fold lesions. In suspected cases of infectious laryngitis, culture is recommended, by biopsy if needed. For MSSA- and MRSA-associated laryngitis, an extended course of antibiotics may be necessary for symptom improvement and resolution of laryngeal inflammation. However, the optimal treatment regimen has yet to be defined and will require larger, prospective studies.

Photo Quiz: Isolation of an Unusual Gram-Positive Coccus from a Positive Blood Culture in a Patient with Pneumonia

A 47-year-old male presented with signs and symptoms of left lower lobe pneumonia. At that time, sputum culture revealed only normal respiratory flora. The patient received intravenous ceftriaxone and azithromycin during his hospitalization, and after his discharge, he completed a 7-day course of

Endoscopic culture-directed antibiotic therapy: Impact on patient symptoms in chronic rhinosinusitis

BackgroundEndoscopically guided cultures are frequently employed to guide antimicrobial therapy in refractory chronic rhinosinusitis (CRS) patients. The objective of this study was to determine the impact of culture-directed antibiotics on patient symptoms. MethodsRetrospective review was conducted of 105 adult CRS patients undergoing evaluation in the ambulatory clinic of tertiary care academic medical center. ResultsThe most common microbes were Staphylococcus aureus (29.5%), Pseudomonas aeruginosa (23.8%) and methicillin-resistant S. aureus (11.4%). Normal respiratory flora or no growth was found in 19% of patients. Culture results changed antibiotic choices in 77% of patients. Statistically significant change in total SNOT-20 scores and all 4 subdomains was noted, with improvement being clinically meaningful in the rhinologic subdomain (−1.10, p<0.0001). Repeat purulence was only noted in 5 cases (4.8%). Multivariate regression analysis demonstrated that concurrent use of oral steroids was independently associated with improvement in the rhinologic subdomain (p=0.0041). The mean length of follow-up was 37days. Length of follow-up (14–30, 31–60, 61–90days) did not statistically impact SNOT-20 scores. ConclusionEndoscopic-derived sinus cultures are associated with clinically meaningful change in the rhinologic subdomain of SNOT-20 scores, and repeat purulence was infrequently noted at follow-up. Further prospective studies are needed to better delineate the role of cultures in CRS management. Level of evidence4.