Endotracheal Aspirate Cultures Research Articles

Diagnosis of ventilator-associated pneumonia

The aim is to discuss the clinical, microbiologic, and radiological criteria used in the diagnosis of ventilator-associated pneumonia (VAP), distinguish between ventilator-associated tracheobronchitis (VAT) and VAP, and reconcile the proposed Centers for Disease Control surveillance criteria with clinical practice. Numerous ventilator-associated complications (VACs), including VAP and VAT, may occur in critically ill, intubated patients. A variety of definitions for identifying VAP have been proposed, but there is no diagnostic gold standard. The proposed surveillance definition will identify infectious and noninfectious VAC, including VAP and VAT, but this definition may be inadequate for clinical practice. The clinical characteristics of VAP and VAT are similar and include fever, leukocytosis, and purulent sputum. An infiltrate on chest radiograph is consistent with VAP but lacks diagnostic precision, so it is not a criterion in the proposed surveillance definition and should be interpreted cautiously by clinicians. Microbiologically, quantitative and semiquantitative endotracheal aspirate cultures may be employed to diagnose VAP and VAT. Positive bronchoalveolar lavage and protected specimen brush cultures are useful only for the diagnosis of VAP. Experts should collaborate to develop consensus definitions for VAP and VAT that can be applied in practice.

The role of endotracheal aspirate culture in the diagnosis of ventilator-associated pneumonia: a meta analysis

To investigate the role of endotracheal aspirate (EA) culture in the diagnosis and antibiotic management in ventilator-associated pneumonia (VAP). We searched CNKI, Wanfang, PUBMED and EMBASE databases published from January 1990 to December 2011, to find relevant literatures on VAP microbiological diagnostic techniques including EA and bronchoalveolar lavage (BALF). The following key words were used: ventilator associated pneumonia, diagnosis and adult. Meta-analysis was performed and the sensitivity and specificity of EA on VAP diagnosis were calculated. Our literature search identified 1665 potential articles, 8 of which fulfilled our selection criteria including 561 patients with paired cultures. Using BALF quantitative culture as reference standard, the sensitivity and specificity of EA were 72% and 71%. When considering quantitative culture of EA only, the sensitivity and specificity improved to 90% and 65%, while the positive and the negative predictive values were 68% and 89% respectively. However, the sensitivity and specificity of semi-quantitative culture of EA were only 50% and 80%, with a positive predictive value of 77% and a negative predictive value of 58% respectively. EA culture had relatively poor sensitivity and specificity, although quantitative culture of EA only could improve the sensitivity. Initiating therapy on the basis of EA quantitative culture may still result in excessive antibiotic usage. Our data suggested that EA could provide some information for clinical decision but could not replace the role of BALF quantitative culture in VAP diagnosis.

A Clinical Algorithm to Diagnose Invasive Pulmonary Aspergillosis in Critically Ill Patients

The clinical relevance of Aspergillus-positive endotracheal aspirates in critically ill patients is difficult to assess. We externally validate a clinical algorithm to discriminate Aspergillus colonization from putative invasive pulmonary aspergillosis in this patient group. We performed a multicenter (n = 30) observational study including critically ill patients with one or more Aspergillus-positive endotracheal aspirate cultures (n = 524). The diagnostic accuracy of this algorithm was evaluated using 115 patients with histopathologic data, considered the gold standard. Subsequently, the diagnostic workout of the algorithm was compared on the total cohort (n = 524), with the categorization based on the diagnostic criteria of the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. Among 115 histopathology-controlled patients, 79 had proven aspergillosis. The algorithm judged 86 of 115 cases to have putative aspergillosis. This diagnosis was confirmed in 72 and rejected in 14 patients. The algorithm judged 29 patients to have Aspergillus colonization. This was confirmed in 22 and rejected in 7 patients. The algorithm had a specificity of 61% and a sensitivity of 92%. The positive and negative predictive values were 61 and 92%, respectively. In the total cohort (n = 524), 79 patients had proven invasive pulmonary aspergillosis (15.1%). According to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 32 patients had probable aspergillosis (6.1%) and 413 patients were not classifiable (78.8%). The algorithm judged 199 patients to have putative aspergillosis (38.0%) and 246 to have Aspergillus colonization (46.9%). The algorithm demonstrated favorable operating characteristics to discriminate Aspergillus respiratory tract colonization from invasive pulmonary aspergillosis in critically ill patients.

Outcome of ventilator-associated pneumonia: Impact of antibiotic therapy and other factors.

Ventilator-associated pneumonia (VAP) is the most frequent infection in patients intubated for longer than 48 hours. There is a great interest in determining the factors influencing the outcome of VAP, as it may help in reducing the associated morbidity and mortality. This study aimed to determine the impact of appropriate antibiotic therapy based on endotracheal aspirate cultures on the outcome of VAP. We have also studied the other factors that may influence the outcome of VAP. A cohort study was conducted in the intensive care units of a tertiary care hospital in South India over a period of 15 months. The outcome of VAP was assessed by prolongation of the duration of mechanical ventilation and/or death of the patient. The duration of mechanical ventilation was significantly prolonged in patients with VAP (16.61 ± 8.2 d vs. 8.21 ± 5.9 d, P < 0.0001). VAP patients receiving partially or totally inappropriate therapy (defined as lack of coverage of one or all the significant VAP pathogens) were at significantly high risk for death (Relative risk, 2.00; 95% confidence interval, 1.14 to 3.52; P 0.0008). A delay of > 2 days in administering the first dose of appropriate antibiotic therapy significantly prolonged the duration of ventilation (P < 0.0001). Infection by multi-drug resistant pathogens, polymicrobial infection and time of onset of VAP did not have significant impact on the outcome of VAP. Early administration of appropriate antibiotic therapy, based on the antibiogram of the VAP pathogens identified by quantitative culture of endotracheal aspirate, could lead to an improved outcome of patients with ventilator-associated pneumonia.

A Rare Case of Pneumonia Caused byShewanella putrefaciens

Shewanella putrefaciens is a gram-negative, nonfermentative, oxidase positive, motile bacillus that produces hydrogen sulphide. It is found widely in the nature especially in marine environments. In some very rare cases Shewanella putrefaciens can be a human pathogen. It can produce a wide variety of clinical syndromes including bacteremia as well as skin and soft tissue infections. However, pneumonia due to S. putrefaciens is rare; there are a total of 4 reported cases in the literature. We present a case of 63-year-old male who was presented to emergency room status after cardiac arrest, fell into sea water face down. On the second day of hospitalization, he was diagnosed to have pneumonia based on the clinical, radiological, and laboratory findings. Empirical antibiotic treatment with vancomycin and piperacillin/tazobactam combination was initiated. Gram-stained smear of endotracheal aspirate yielded gram-negative bacteria, and the isolate grown from endotracheal aspirate culture was identified as S. putrefaciens by Biomerieux API 20 NE technique. On review of the literature and according to culture and sensitivity results, therapy in our patient was changed to cefepime. Patient's pneumonia improved with treatment with cefepime. We believe that our patient developed pneumonia evidently caused by S. putrefaciens, after near drowning in sea water. The pneumonia resolved after treatment with cefepime.

Implications of endotracheal tube biofilm in ventilator-associated pneumonia response: a state of concept

IntroductionBiofilm in endotracheal tubes (ETT) of ventilated patients has been suggested to play a role in the development of ventilator-associated pneumonia (VAP). Our purpose was to analyze the formation of ETT biofilm and its implication in the response and relapse of VAP.MethodsWe performed a prospective, observational study in a medical intensive care unit. Patients mechanically ventilated for more than 24 hours were consecutively included. We obtained surveillance endotracheal aspirates (ETA) twice weekly and, at extubation, ETTs were processed for microbiological assessment and scanning electron microscopy.ResultsEighty-seven percent of the patients were colonized based on ETA cultures. Biofilm was found in 95% of the ETTs. In 56% of the cases, the same microorganism grew in ETA and biofilm. In both samples the most frequent bacteria isolated were Acinetobacter baumannii and Pseudomonas aeruginosa. Nineteen percent of the patients developed VAP (N = 14), and etiology was predicted by ETA in 100% of the cases. Despite appropriate antibiotic treatment, bacteria involved in VAP were found in biofilm (50%). In this situation, microbial persistence and impaired response to treatment (treatment failure and relapse) were more frequent (100% vs 29%, P = 0.021; 57% vs 14%, P = 0.133).ConclusionsAirway bacterial colonization and biofilm formation on ETTs are early and frequent events in ventilated patients. There is microbiological continuity between airway colonization, biofilm formation and VAP development. Biofilm stands as a pathogenic mechanism for microbial persistence, and impaired response to treatment in VAP.

Post-influenza Pneumonia Caused by the USA300 Community-Associated Methicillin-ResistantStaphylococcus aureusin Korea

Panton-Valentine leukocidin (PVL)-positive USA300 clone has been the most successful community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone spreading in North America. In contrast, PVL-negative ST72-CA-MRSA has been predominant in Korea, and there has been no report of infections by the USA300 strain except only one case report of perianal infection. Here, we describe the first case of pneumonia caused by the USA300 strain following pandemic influenza A (H1N1) in Korea. A 50-year-old man was admitted with fever and cough and chest radiograph showed pneumonic consolidation at the right lower lung zone. He received a ventilator support because of respiratory failure. PCR for pandemic influenza A (H1N1) in nasopharyngeal swab was positive, and culture of sputum and endotracheal aspirate grew MRSA. Typing of the isolate revealed that it was PVL-positive, ST 8-MRSA-SCCmec type IV. The analysis of the PFGE patterns showed that this isolate was the same pulsotype as the USA300 strain.

Ventilator associated pneumonia in a medical intensive care unit: Microbial aetiology, susceptibility patterns of isolated microorganisms and outcome

Background:Ventilator-associated pneumonia (VAP) is a common complication of ventilatory support for patients with acute respiratory failure and is associated with increased morbidity and mortality.Aim of the Study:The present study was undertaken to do quantitative cultures of aerobic bacteria, perform the antibiotic susceptibility testing from the endotracheal aspirates and clinical outcome of the clinically suspected patients of VAP.Methods:A prospective study was performed over a period of one year in a tertiary care hospital, enrolling patients on mechanical ventilation (MV) for ≥48 hr. Endotracheal aspirates (ETA) were collected from patients with suspected VAP, and direct gram's stain criteria was used to accept the sample. Quantitative cultures of ETA were performed with the threshold for microbiological diagnosis of VAP was taken as ≥105 colony forming units (cfu)/ml.Results:Out of 53 cases, 2 (3.77%) were polymicrobial. Multidrug resistant bacteria, mainly Acinetobacter baumannii 49.09% (27/55) and Pseudomonas aeruginosa 30.91% (17/55) were the most common pathogens isolated. Metallo-beta lactamases (MBLs) was produced by 47.06% (8/17) of Pseudomonas aeruginosa and 62.96% (17/27) of Acinetobacter baumannii.Conclusion:The bacteriological approach for the management of VAP helps the clinicians in choosing the appropriate antibiotics. This study showed that quantitative cultures of endotracheal aspirate at a cutoff point of 105 cfu/ml is one of the alternative to bronchoscopy in the diagnosis of clinically suspected ventilator associated pneumonia.

Uso de cultivo cuantitativo de aspirado endotraqueal para el diagnóstico de neumonía asociada a ventilación mecánica en pediatría: estudio prospectivo, analítico

Ventilator-associated pneumonia (VAP) is dificult to diagnose because of the absence of a gold standard.To evaluate the use of quantitative cultures of endotracheal aspirates for diagnosis of pediatric VAP and to obtain acceptable sensitivity and specificity cutoff points.Prospective, analytic study which included patients under 15 years, who were connected to mechanical ventilation at Hospital Luis Calvo Mackenna's intensive care units. They were classified as cases or controls according to NNIS criteria.During a period of 21 months we recruited a total of 43 patients with a mean age of 16 months. We obtained endotracheal aspirated samples to perform quantitative cultures. Most frequently isolated pathogens were Staphylococcus aureus (34.5%) and non-fermentative Gram-negative bacilli (24.1%). We obtained a sensitivity of 88%, specificity of 70%, PPV of 82%, and NPV of 79% for samples greater than 10(6) CFU.Quantitative culture of endotracheal aspirates is a reliable method for diagnosing pediatric VAP when the value is greater than 10 CFU.

Evaluation of quantitative cultures of endotracheal aspirates for pediatric ventilator-associated pneumonia diagnosis: analytic, prospective study

Ventilator-associated pneumonia (VAP) is dificult to diagnose because of the absence of a gold standard. To evaluate the use of quantitative cultures of endotracheal aspirates for diagnosis of pediatric VAP and to obtain acceptable sensitivity and specificity cutoff points. Prospective, analytic study which included patients under 15 years, who were connected to mechanical ventilation at Hospital Luis Calvo Mackenna's intensive care units. They were classified as cases or controls according to NNIS criteria. During a period of 21 months we recruited a total of 43 patients with a mean age of 16 months. We obtained endotracheal aspirated samples to perform quantitative cultures. Most frequently isolated pathogens were Staphylococcus aureus (34.5%) and non-fermentative Gram-negative bacilli (24.1%). We obtained a sensitivity of 88%, specificity of 70%, PPV of 82%, and NPV of 79% for samples greater than 10(6) CFU. Quantitative culture of endotracheal aspirates is a reliable method for diagnosing pediatric VAP when the value is greater than 10 CFU.

Pneumonia Due to Pseudomonas aeruginosa: Part I: Epidemiology, Clinical Diagnosis, and Source

Pseudomonas aeruginosa is an uncommon cause of community-acquired pneumonia (CAP), but a common cause of hospital-acquired pneumonia. Controversies exist for diagnostic methods and antibiotic therapy. We review the epidemiology of CAP, including that in patients with HIV and also in hospital-acquired pneumonia, including ventilator-associated pneumonia (VAP) and bronchoscope-associated pneumonia. We performed a literature review of clinical studies involving P aeruginosa pneumonia with an emphasis on treatment and prevention. Pneumonia due to P aeruginosa occurs in several distinct syndromes: (1) CAP, usually in patients with chronic lung disease; (2) hospital-acquired pneumonia, usually occurring in the ICU; and (3) bacteremic P aeruginosa pneumonia, usually in the neutropenic host. Radiologic manifestations are nonspecific. Colonization with P aeruginosa in COPD and in hospitalized patients is a well established phenomenon such that treatment based on respiratory tract cultures may lead to overtreatment. We present circumstantial evidence that the incidence of P aeruginosa has been overestimated for hospital-acquired pneumonia and reflex administration of empirical antipseudomonal antibiotic therapy may be unnecessary. A diagnostic approach with BAL and protected specimen brush using quantitative cultures for patients with VAP led to a decrease in broad-spectrum antibiotic use and improved outcome. Endotracheal aspirate cultures with quantitative counts are commonly used, but validation is lacking. An empirical approach using the Clinical Pulmonary Infection Score is a pragmatic approach that minimizes antibiotic resistance and leads to decreased mortality in patients in the ICU. The source of the P aeruginosa may be endogenous (from respiratory or GI tract colonization) or exogenous from tap water in hospital-acquired pneumonia. The latter source is amenable to preventive measures.

Interpreting positive cultures of endotracheal aspirates: Factors associated with treatment decisions in ventilated neonates

Diagnosis of ventilator-associated pneumonia in newborns is challenging because of ease of colonisation, non-specific chest radiograph changes and lack of a consensus definition. The aims of this study were to review treatment decisions in neonates with culture-positive endotracheal aspirate and to assess impact on respiratory outcomes using blinded review of radiological studies. Charts from all very low birthweight neonates ventilated for >48 h and with positive culture were assessed. Chest radiographs were reviewed by a radiologist masked to the grouping of the episode (treated/not treated). Clinical, investigational and radiological features used in practice were assessed on impact on treatment decisions. Association between treatment and outcomes was assessed. Seventy-four episodes of culture-positive endotracheal aspirate were analysed in 38 babies. Fifty-eight episodes were treated with antibiotics. Gestational age at birth and birthweight in both groups (treated vs. non-treated) were statistically comparable (25.5 ± 3.1 vs. 27.2 ± 2.3 weeks and 809 ± 302 vs. 870 ± 262 g). Comparative chest radiographs were available in 51 of 58 treated episodes; deterioration was noted in 42 (82.3%). Ventilatory parameters were significantly higher in the treatment group and showed a significant improvement after antibiotics. Twenty-three babies developed chronic lung disease. Odds ratio (of having chronic lung disease when treatment is initiated) was 4.5 (95% confidence interval = 0.97-20.8, P= 0.06). Treated culture-positive aspirate episodes were accompanied by higher ventilatory requirements, increased symptoms and elevated septic markers. Need for treatment was associated with greater likelihood of developing chronic lung disease.

Selective digestive tract decontamination and selective oropharyngeal decontamination and antibiotic resistance in patients in intensive-care units: an open-label, clustered group-randomised, crossover study

Previously, we assessed selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) on survival and prevention of bacteraemia in patients in intensive-care units. In this analysis, we aimed to assess effectiveness of these interventions for prevention of respiratory tract colonisation and bacteraemia with highly resistant microorganisms acquired in intensive-care units. We did an open-label, clustered group-randomised, crossover study in 13 intensive-care units in the Netherlands between May, 2004, and July, 2006. Participants admitted to intensive-care units with an expected duration of mechanical ventilation of more than 48 h or an expected stay of more than 72 h received SOD (topical tobramycin, colistin, and amphotericin B in the oropharynx), SDD (SOD antibiotics in the oropharynx and stomach plus 4 days' intravenous cefotaxime), or standard care. The computer-randomised order of study regimens was applied by an independent clinical pharmacist who was masked to intensive-care-unit identity. We calculated crude odds ratios (95% CI) for rates of bacteraemia or respiratory tract colonisation with highly resistant microorganisms in patients who stayed in intensive-care units for more than 3 days (ie, acquired infection). This trial is registered at http://isrctn.org, number ISRCTN35176830. Data were available for 5927 (>99%) of 5939 patients, of whom 5463 (92%) were in intensive-care units for more than 3 days. 239 (13%) of 1837 patients in standard care acquired bacteraemia after 3 days, compared with 158 (9%) of 1758 in SOD (odds ratio 0·66, 95% CI 0·53-0·82), and 124 (7%) of 1868 in SDD (0·48, 0·38-0·60). Eight patients acquired bacteraemia with highly resistant microorganisms during SDD, compared with 18 patients (with 19 episodes) during standard care (0·41, 0·18-0·94; rate reduction [RR] 59%, absolute risk reduction [ARR] 0·6%) and 20 during SOD (0·37, 0·16-0·85; RR 63%, ARR 0·7%). Of the patients staying in intensive-care units for more than 3 days, we obtained endotracheal aspirate cultures for 881 (49%) patients receiving standard care, 886 (50%) receiving SOD, and 828 (44%) receiving SDD. 128 (15%) patients acquired respiratory tract colonisation with highly resistant microorganisms during standard care, compared with 74 (8%) during SDD (0·58, 0·43-0·78; RR 38%, ARR 5·5%) and 88 (10%) during SOD (0·65, 0·49-0·87; RR 32%, ARR 4·6%). Acquired respiratory tract colonisation with Gram-negative bacteria or cefotaxime-resistant and colistin-resistant pathogens was lowest during SDD. Widespread use of SDD and SOD in intensive-care units with low levels of antibiotic resistance is justified. None.

Polymerase chain reaction assay for the detection of Acinetobacter baumannii in endotracheal aspirates from patients in the intensive care unit

We aim to evaluate the efficacy of polymerase chain reaction (PCR) to detect Acinetobacter baumannii in endotracheal aspirates. Endotracheal aspirates and clinical data were collected from patients who were admitted to the intensive care unit of Taipei Veterans General Hospital between April 1 and August 31 in 2006. Bacterial isolates from endotracheal aspirate cultures were phenotypically identified as Acinetobacter calcoaceticus-A baumannii complex using the API ID 32GN system. The presence of A baumannii in the aspirate was also directly detected by multiplex PCR. Ten of the 114 endotracheal aspirate cultures were positive for A calcoaceticus-A baumannii complex, and only nine of the isolates were confirmed as A baumannii by the multiplex PCR. Direct PCR detection showed that 40 (35.1%) of the endotracheal aspirates were positive for A baumannii. Using positive culture of A baumannii as the gold standard, the sensitivity of direct PCR detection was 100% (6 of 6), the specificity was 70.4% (38 of 54), the positive predictive value was 27.3% (6 of 22), and the negative predictive value (NPV) was 100% (38 of 38) among patients with A baumannii pneumonia. Among patients with A baumannii colonization, the sensitivity of direct PCR detection was 100% (3 of 3), the specificity was 70.6% (36 of 51), the positive predictive value was 16.7% (3 of 18), and the NPV was 100% (36 of 36). Direct PCR detection of A baumannii in endotracheal aspirates has a high sensitivity and NPV as compared with culture-based methods. Further studies are needed to determine the clinical applicability of this rapid detection test.

Usefulness of Quantitative Endotracheal Aspirate Cultures in Intensive Care Unit Patients with Suspected Pneumonia

It is difficult to differentiate pathogens responsible for pneumonia or colonization in patients with an endotracheal tube or in patients that have undergone tracheostomy. We evaluated the clinical usefulness of quantitative endotracheal aspirates cultures and sought to determine the result threshold level for positivity. The authors performed this retrospective cohort study between December 1, 2004 and January 31, 2006. Forty-five suspected pneumonia patients admitted to an intensive care unit (ICU) with quantitative bronchoalveolar lavage (BAL) and endotracheal aspirate (EA) culture results were enrolled. Using a threshold of 105 cfu/mL, 10 of the 45 (22.2%) quantitative EA cultures were positive, as compared with 7 (15.6%) BAL cultures. When BAL culture findings were used as the reference, the sensitivity and specificity of quantitative EA cultures were 85.7% and 89.5%, respectively, at a threshold of 105 cfu/mL, and 85.7% and 94.7%, respectively, at a threshold of 106 cfu/mL. Of the 10 EA culture positive patients, 2 patients with a result of -105 cfu/mL were BAL culture negative. The quantitative EA culture is a useful non-invasive tool for the diagnosis of pneumonia pathogens. It is suggested that a threshold level of 106 cfu/mL is appropriate.

Role of semi-quantitative and quantitative cultures of endotracheal aspirates in the diagnosis of ventilator-associated pneumonia

Background Ventilator-associated pneumonia (VAP) is an important nosocomial infection among patients on mechanical ventilation. Modified clinical pulmonary infection score (CPIS) is used widely for diagnosis of VAP. There is a need for a non-invasive microbiological technique for diagnosis of VAP. Therefore, we performed a prospective study to determine the diagnostic value of semi-quantitative and quantitative cultures of endotracheal aspirates (EA) in VAP.

Severe ventilator-associated pneumonia caused by methicillin-resistant Staphylococcus aureus and other pathogens: report of a case successfully managed by serial surveillance cultures of endotracheal aspirates

Severe ventilator-associated pneumonia (VAP) caused by methicillin-resistant Staphylococcus aureus (MRSA) developed in a patient with acute respiratory distress syndrome. After tracheostomy, the patient was treated with antibiotic therapy guided by serial surveillance cultures of endotracheal aspirates. According to the result of the culture, the suitable antibiotic targeting the pathogen (e.g., MRSA, Pseudomonas aeruginosa, Klebsiella oxytoca) that had grown most predominantly in the culture was used until clinical resolution of VAP, leading to avoidance of overusing broad-spectrum antibiotics and ultimately a favorable outcome. During vancomycin (VCM) therapy for MRSA VAP, MRSA bacteremia occurred even though the trough value of VCM was sufficiently high. After the change from VCM to linezolid (LZD), the VAP improved promptly, indicating that LZD is superior to VCM in the treatment of MRSA pneumonia.

Dangers in the garden

In March, 2010, a previously fi t and healthy 67-year-old man presented with an 8-day history of fever with rigors, intermittent confusion, lethargy, and shortness of breath. On admission, he was febrile with a temperature of 39°C and had clinical signs of a left-sided pneumonia, accompanied by general abdominal tenderness. His white blood cell count was 14·8×10/L (number of neutrophils was 11·3×109/L, and lymphocyles 0·2×10/L), and C-reactive protein concentration was raised at 475 mg/L. Renal, and liver function were abnormal: urea concentration was 21·6 mmol/L; creatinine 257 μmol/L; sodium 135 mmol/L; potassium 4 mmol/L; aspartate aminotransferase 115 IU/L; alanine aminotransferase 80 IU/L; and bilirubin 56 μmol/L. A chest radiograph showed complete opacifi cation of his left lung. We suspected an atypical or viral pneumonia; however, urinary legionella and pneumococcal antigens, PCR for infl uenza A and B, and microscopy and culture of endotracheal tube aspirate, were negative. We treated our patient with oxygen, intravenous fl uids, and antibiotics (amoxicillin-clavulanate and clarithromycin), but his respiratory function deteriorated, necessitating transfer to the intensive care unit for intubation. The day after presentation we did a bronchoalveolar lavage to obtain a sputum specimen; we then added levofl oxacin to his treatment. 3 days later, a positive culture result for Legionella longbeachae was confi rmed from growth on legionella-specifi c medium. When we questioned the patient to fi nd out the source of this infection, we discovered that he was a keen gardener and had lacerated his left index fi nger 2 days before the onset of his symptoms, while planting with compost; we presumed that this cut was the site of entry of the organism. Our patient continued to improve and was discharged to a respiratory ward 7 days later. He was discharged home in April, 2010, and was well at followup in May, 2010. Legionnaires’ disease is a common pneumonia that is usually caused by Legionella pneumophila (about 90% of cases); it can be readily diagnosed by urinary antigen testing. Legionnaires’ disease caused by L longbeachae is much less common, and outbreaks in the UK and the USA are sporadic. In the UK, nine cases have been reported since 1984; in the USA the majority of cases reported to the Centers for Disease Control and Prevention between 1990 and 1999 were in immunocompromised patients. L longbeachae has a much higher incidence in Australia, New Zealand, and Japan, where it accounts for about 30% of all cases of Legionnaires’ disease. The clinical presentation and prognosis of disease caused by these Legionella species are similar; however, L longbeachae cannot be detected by urinary antigen testing (which is sensitive only for serogroup 1 species), and disease caused by this organism generally has to be diagnosed by culture of a bronchoalveolar lavage sample. Previous case studies have shown compost to be a source of the infection. The antibiotic choice in the management of Legionnaires’ disease is the same whatever the causative organism. Most cases are resistant to β-lactam antibiotics, but are sensitive to macrolides or new quinolone antibiotics, such as levofl oxacin. Despite the low incidence of Legionnaires’ disease caused by L longbeachae in the UK and the USA, continued treatment with macrolides or quinolones in cases of severe community-acquired pneumonia may be prudent, particularly in those associated with exposure to gardening compost, until full culture results on legionella-specifi c medium are available. The UK Royal Horticultural Society has issued warnings about the risk of contracting Legionnaires’ disease from handling compost and has announced that bags of potting compost will carry cautionary statements.

The Impact of Qualitative Respiratory Cultures on Mortality in Critically III Patients with Hospital-Acquired Pneumonia

This retrospective cohort study evaluated differences in all-cause mortality associated with quantitative versus qualitative cultures in critically ill patients with suspected hospital-acquired pneumonia (HAP). Patients were included if lower respiratory tract (LRT) cultures were obtained and were stratified by culture strategy: invasive (bronchial alveolar lavage [BAL] or nonbronchoscopic BAL) or noninvasive (endotracheal tube aspirate or sputum culture). Mortality data and secondary endpoints were compared between groups. A total of 113 patients met inclusion criteria (invasive = 72, noninvasive = 41). No significant difference in all-cause mortality was detected between the groups (37.5% and 31.7%, respectively; P = 0.54). Secondary endpoints were similar; however, patients in the invasive group had greater mean total antibiotic days of therapy compared to the noninvasive group (21.2 ± 13.5 days vs 15.5 ± 8.3 days, P = 0.01). The present study suggests that using invasive methods to obtain LRT cultures in critically ill patients with suspected HAP did not offer a detectable benefit in mortality or clinical outcomes when compared to noninvasive diagnostic methods.

Clinical, radiological and microbiological corroboration to assess the role of endotracheal aspirate in diagnosing ventilator-associated pneumonia in an intensive care unit of a tertiary care hospital, India

Early and accurate diagnosis and follow up of Ventilator-associated pneumonia (VAP) varies considerably with the clinical, radiological and microbiological criteria employed. this study was aimed to correlate serial clinicoradiological findings with microscopy and quantitative culture of consecutive Endotracheal aspirate (ETA) from 50 mechanically ventilated patients along with the antibiogram and risk factor assessment. the results revealed the incidence of VAP to be 42% with a rate of 116/1000 ventilator days in Multidisciplinary Intensive Care Unit (MICU). Early onset VAP was seen in 8 patients and late onset VAP in 13, with no significant age or sex preponderance. the attributable mortality rate was 61.9% which rose with duration of stay. the independent risk factors were multi-organ failure, re-intubation and pleural effusion. the most commonly isolated organisms were Multidrug resistant (MDR) Acinetobacter baumannii (76%) and Pseudomonas aeruginosa (42%). All enterobacterial isolates were Extended spectrum beta lactamases (ESBL) producing organisms and all Staphylococcus aureus isolates were methicillin resistant. Colonization on day 1 resulted in development of VAP on day 4 in 66% of the population studied. Gram stain findings had a significant correlation with the quantitative culture of ETA. Quantitative culture by itself showed a significant progressive increase of specificity in diagnosing VAP on day 7. he strength of association between Clinical Pulmonary Infection Score (CPIS), the microbiological findings and the clinical diagnosis was found to be strong. This study concludes that Gram stain and quantitative culture of ETA can be considered useful for the diagnosis of VAP and a combined clinical, radiological and microbiological approach can be used successfully in the management and follow up of VAP with emphasis on stepping up the VAP prevention bundle protocols.