Molecular epidemiology of Pseudomonas aeruginosa isolated from lower respiratory tract of ICU patients / Epidemiologia molecular de Pseudomonas aeruginosa isolada em pacientes com infecções do trato respiratório inferior admitidos em UTI

Lower respiratory tract infections (LRTIs) caused by Pseudomonas aeruginosa are the most common infection among hospitalized patients, associated with increased levels of morbidity, mortality and attributable health care costs. Increased resistant Pseudomonas worldwide has been quite meaningful to patients, especially in intensive care unit (ICUs). Different species of Pseudomonas exhibit different genetic profile and varied drug resistance. The present study determines the molecular epidemiology through DNA fingerprinting method and drug resistance of P. aeruginosa isolated from patients with LTRIs admitted in ICU. A total of 79 P. aeruginosa isolated from patients with LRTIs admitted in ICU were characterized by Restriction Fragment Length Polymorphism (RFLP), Random Amplified Polymorphic DNA (RAPD) and Repetitive Extrapalindromic PCR (REP-PCR). Antibiotic resistance was determined by minimum inhibitory concentration (MIC) assay while MDR genes, viz, blaTEM, blaOXA, blaVIM, blaCTX-M-15 were detected by polymerase chain reaction (PCR). Of the 137 Pseudomonas sp isolated from ICU patients, 57.7% of the isolates were reported to be P. aeruginosa. The overall prevalence of P. aeruginosa among the all included patients was 34.5%. The RAPD analysis yielded 45 different patterns with 72 clusters with 57% to 100% similarity level. The RFLP analysis yielded 8 different patterns with 14 clusters with 76% to 100% similarity level. The REP PCR analysis yielded 37 different patterns with 65 clusters with 56% to 100% similarity level. There was no correlation among the different DNA patterns observed between the three different methods. Predominant of the isolates (46.8%) were resistant to amikacin. Of the 79 isolates, 60.8% were positive for blaTEM gene and 39.2% were positive for blaOXA gene. P. aeruginosa was predominantly isolated from patients with LRTIs admitted in ICU. The difference in the similarity level observed between the three DNA fingerprinting methods indicates that there is high inter-strain variability. The high genetic variability and resistance patterns indicates that we should continuously monitor the trend in the prevalence and antibiotic resistance of P. aeruginosa especially in patients with LRTIs admitted in ICU.

Infecções do trato respiratório inferior (ITRIs) são as infecções mais comuns entre pacientes internados em unidade de terapia intensiva (UTI). Pseudomonas aeruginosa é a causa mais comum de ITRIs e está associada ao aumento da mortalidade. Diferentes espécies de Pseudomonas exibem diferentes perfis genéticos e resistência variada as drogas. O presente estudo determina a epidemiologia molecular através do método de fingerprinting de DNA e resistência as drogas de P. aeruginosa isoladas de pacientes com LTRIs internados em UTI. Um total de 79 P. aeruginosa isoladas de pacientes com ITRIs internados em UTI foram caracterizados por Polimorfismo de Comprimento de Fragmentos de Restrição (RFLP), DNA Polimórfico Amplificado ao Acaso (RAPD) e PCR Extrapalindrômico Repetitivo (REP-PCR). A resistência aos antibióticos foram determinadas pelos ensaios de concentrações inibitória mínima (MIC), enquanto os genes MDR, blaTEM, blaOXA, blaVIM, blaCTX-M-15 foram detectados pela reação em cadeia da polimerase (PCR). Das 137 Pseudomonas sp isoladas de pacientes de UTI, 57,7% dos isolados foram relatados como P. aeruginosa. A prevalência geral de P. aeruginosa entre os pacientes incluídos foram de 34,5%. A análise RAPD renderam 45 padrões diferentes com 72 clusters com nível de similaridade de 57% a 100%. A análise RFLP renderam 8 padrões diferentes com 14 clusters com 76% a 100% de similaridade. A análise de PCR do REP produziram 37 padrões diferentes com 65 clusters com nível de similaridade de 56% a 100%. Não houveram correlações entre os diferentes padrões de DNA observados entre os três diferentes métodos. Predominantes dos isolados (46,8%) eram resistentes à amicacina. Dos 79 isolados, 60,8% foram positivos para o gene blaTEM e 39,2% foram positivos para o gene blaOXA. P. aeruginosa foi predominantemente isolado de pacientes com ITRIs internados em UTI. A diferença no nível de similaridade observado entre os três métodos de fingerprinting do DNA indica que há alta variabilidade inter-strain. A alta variabilidade genética e os padrões de resistência indicam que devemos monitorar continuamente a tendência na prevalência e resistência a antibióticos de P. aeruginosa, especialmente em pacientes com ITRIs internados em UTI.

Caracterización molecular de bacterias patógenas de las vías respiratorias de pacientes peruanos con fibrosis quística / Molecular characterization of pathogenic bacteria of the respiratory tract in peruvian patients with cystic fibrosis

RESUMEN Objetivos. Caracterizar a nivel molecular las bacterias patógenas de las vías respiratorias de pacientes peruanos con fibrosis quística (FQ). Materiales y métodos. Se caracterizaron las comunidades bacterianas cultivables a partir de muestras de esputo de pacientes pediátricos y adultos con FQ registrados en el Hospital Nacional Edgardo Rebagliati Martins y el Instituto Nacional de Salud del Niño (INSN). Para el cultivo bacteriano se utilizaron técnicas microbiológicas estándares, y para la caracterización molecular la secuenciación del gen ARNr 16S y espectrometría de masas de tipo desorción/ionización con láser asistido por matriz con tiempo de vuelo (MALDI TOF) y MALDI TOF/TOF. Resultados. Por secuenciación del ARNr 16S se identificaron 127 cepas, encontrando las bacterias patógenas Pseudomonas aeruginosa (31,5%), Staphylococcus aureus (12,6%), Pseudomonas spp. (11,8%), Klebsiella oxytoca (3,1%), otras especies mostraron baja prevalencia. El análisis por MALDI TOF permitió obtener una serie de espectros representativos de cada especie aislada, mientras que el análisis por MALDI TOF/TOF reveló péptidos y proteínas de las especies más comunes con informaciones complementarias que revelarían datos sobre su patogenicidad o sensibilidad a antibióticos. Conclusiones. Los principales microorganismos patógenos encontrados en las vías respiratorias son similares a los reportados en otros países. Estos son los primeros hallazgos en Perú que muestran la caracterización bacteriana por secuenciación del ARNr 16S, por MALDI TOF y MALDI TOF TOF. Los hallazgos permiten la identificación bacteriana de microorganismos nativos relacionados con la FQ basada en el análisis de su proteoma.

ABSTRACT Objectives. To molecularly characterize the pathogenic bacteria of the respiratory tract isolated from patients with cystic fibrosis (CF) in Peru. Materials and methods. Bacterial communities cultured from sputum samples of pediatric and adult patients with CF admitted to the Edgardo Rebagliati Martins National Hospital and the National Institute of Child Health were characterized. Standard microbiological techniques were used for bacterial culture, and gene sequencing of 16S rRNA and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and tandem MALDI-TOF mass spectrometry (MALDI TOF/TOF) were used for molecular characterization. Results. Seventeen bacterial strains were characterized by 16S rRNA sequencing, and the identified pathogenic bacteria were Pseudomonas aeruginosa (31.5%), Staphylococcus aureus (12.6%), Pseudomonas spp. (11.8%), and Klebsiella oxytoca (3.1%). MALDI-TOF analysis generated a series of spectra representative of each isolated bacterial species, whereas MALDI TOF/TOF analysis identified the peptides and proteins of the most common strains and provided data on pathogenicity and sensitivity to antibiotics. Conclusions. The primary pathogenic microorganisms found in the respiratory tract of patients with CF in Peru were the same as those found in other countries. This study is the first to perform 16S rRNA sequencing as well as MALDI-TOF and MALDI-TOF/TOF analysis of the bacterial pathogens circulating in Peru. The inclusion of proteomic analysis further allowed for the identification of native microorganisms involved in CF.

Identificación molecular de Candida lusitaniae en infección de tracto respiratorio inferior / Molecular identification of Candida lusitaniae in lower respiratory tract infection

Candida lusitaniae es una levadura que ha sido descrita como un patógeno nosocomial emergente de baja frecuencia en infecciones profundas. La identificación oportuna de C. lusitaniae es importante porque puede desarrollar resistencia in vivo a la amfotericina B durante la terapia. Reportamos el aislamiento de C. lusitaniae como agente etiológico de infección de tracto respiratorio inferior en un paciente masculino. Los cultivos de orina y esputo fueron negativos para bacterias y positivos para esta levadura. Los aislamientos fueron identificados por métodos fenotípicos de rutina y confirmados por secuenciación y polimorfismos de longitud de fragmentos de restricción y PCR de la región espaciadora interna del DNA ribosómico.

The yeast Candida lusitaniae has been described as an emerging low frequency nosocomial pathogen in deep infections. Early identification of C. lusitaniae is important because it can readily develop in vivo resistance to amphotericin B during treatment. We report the isolation of C. lusitaniae as etiologic agent of a lower respiratory tract infection in a male patient. Urine and sputum cultures were negative for bacteria and positive for yeast. Isolates were identified by routine phenotypic methods and confirmed by ribosomal DNA internal spacer region restriction fragment length polymorphism PCR and sequencing.

Biofilm Formation and Antifungal Susceptibility of Candida Isolates from Various Clinical Specimens.

Background: Candida species are now recognized as major causative agents of hospitalacquired infection. Aims: To evaluate the species distribution, biofilm formation,and antifungal susceptibility (amphotericin B, ketoconazole, and fluconazole) of Candida isolates. Place and Duration of Study: This is a Six-months Cross sectional study conducted in Alansar hospital, Al-Madinah, Saudi Arabia. Methodology: One hundred and three isolates of Candida spp. were cultured on Sabouraud dextrose agar (SDA). Candida spp. were identified by four standard methods, CHROMagar candida, cornmeal agar, germ tube test and API 20C. Detection of Biofilm formation was done by microtitre plate and antifungal susceptibility testing was done by disc diffusion. Results: C. albicans was the most common species 61%, followed by C. tropicalis 25%, C. lusitanaie 5%, C. parapsilosis 4%, C. glabrata 4% and C. famata 1%. Biofilm formation was found to occur most frequently among non-albicans spp.(70%) than C. albicans (46%). All isolates were sensitive to amphotericin B and ketoconazole. Resistance to fluconazole was found in 22.5% of non-albicans spp. and 5% of C. albicans isolates. Conclusion: The present study proved that C. albicans is still the major isolate from urinary, vaginal and respiratory samples but non-albicans spp. predominate in the blood samples and from plastic devices. The non-albicans spp. were more biofilm - producers compared to C. albicans and C. tropicalis showed the highest score of biofilm intensity (grade 4+). The species isolated are less susceptible to fluconazole.

Aislamientos bacterianos de muestras respiratorias de pacientes pediátricos con fibrosis quística y su distribución por edades / [Bacterial isolates from respiratory samples of pediatric patients with cystic fibrosis and their distribution by ages].

The bacterial isolates from respiratory samples of 50 pediatric patients with cystic fibrosis, their distribution by ages and antimicrobial resistance pattern as well as the intermittence of isolations and coinfections, were investigated. Staphylococcus aureus was isolated in 72

of patients, followed by Pseudomonas aeruginosa (58

), and the Burkholderia cepacia complex (12

). The frequency of resistance of P. aeruginosa isolates to ß-lactam antibiotics was low (13.8

). Fifty percent of S. aureus isolates was methicillin-resistant, and 57.1

of H. influenza was ampicillin resistant due to ß-lactamase production. In children under 4 years-old, S. aureus was predominant, followed by P. aeruginosa and H. influenzae. This order of predominance was observed in all the groups studied, except in that of children between 10 and 14 years-old. Stenotrophomonas maltophilia and Achromobacter xylosoxidans isolates were intermittent and accompanied by other microorganisms. Finally, we observed a great variety of bacterial species, which imposes stringent performance requirements for microbiological studies in all respiratory samples of these patients.

Evaluation of Peptide Nucleic Acid Probe-based Real-time PCR for Detection of Mycobacterium tuberculosis Complex and Nontuberculous Mycobacteria in Respiratory Specimens

BACKGROUND: A peptide nucleic acid (PNA) probe-based real-time PCR (PNAqPCR(TM) TB/NTM detection kit; PANAGENE, Korea) assay has been recently developed for the simultaneous detection of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) in clinical specimens. The study was aimed at evaluation of the performance of PNA probe-based real-time PCR in respiratory specimens. METHODS: To evaluate potential cross-reactivity, the extracted DNA specimens from Mycobacterium species and non-mycobacterial species were tested using PNA probe-based real-time PCR assay. A total of 531 respiratory specimens (482 sputum specimens and 49 bronchoalveolar washing fluid specimens) were collected from 230 patients in July and August, 2011. All specimens were analyzed for the detection of mycobacteria by direct smear examination, mycobacterial culture, and PNA probe-based real-time PCR assay. RESULTS: In cross-reactivity tests, no false-positive or false-negative results were evident. When the culture method was used as the gold standard test for comparison, PNA probe-based real-time PCR assay for detection of MTBC had a sensitivity and specificity of 96.7% (58/60) and 99.6% (469/471), respectively. Assuming the combination of culture and clinical diagnosis as the standard, the sensitivity and specificity of the new real-time PCR assay for detection of MTBC were 90.6% (58/64) and 99.6% (465/467), respectively. The new real-time PCR for the detection of NTM had a sensitivity and specificity of 69.0% (29/42) and 100% (489/489), respectively. CONCLUSIONS: The new real-time PCR assay may be useful for the detection of MTBC in respiratory specimens and for discrimination of NTM from MTBC.

Respiratory tract culture: could it be an additional diagnostic modality of neonatal sepsis?

Study objective is to evaluate the role of respiratory tract colonization pattern-in predicting pathogens isolated during episodes of neonatal sepsis. A prospective study including 50 septic newborns [21 full term and 29 preterm] was carried in the neonatal intensive care units [NICUs] of Cairo University [Kasr el Aini and Abou el Riche Children Hospital] during the period between March 2007 and December 2007. In addition to routine laboratory work up for sepsis, culture was performed on respiratory specimens obtained using either blind [non bronchoscopic] bronchoalveolar lavage [BAL] or tracheal aspirate [TA]. Comparing blood and respiratory cultures regarding the presence of bacterial growth, there was a statistically significant relation between them; as we retrieved the same organism in almost 30% of cases. In conclusion, Culture of tracheal secretions could be of use as an indicator of changes taking place in the NICU environment. However, it is recommended only if clinical signs point out pneumonia, associated with variation in amount and character of secretions, even if the chest x-ray shows no abnormality. Cultures of tracheal aspirates could not substitute the blood culture in diagnosis of neonatal sepsis

Antimicrobial resistance of bacterial agents of the upper respiratory tract of school children in Buea, Cameroon.

The study was aimed at determining bacterial agents of the upper respiratory tract and the susceptibility patterns of isolates to antibiotics. In total, 200 throat swabs were obtained from students attending different boarding schools within the Buea Municipality and screened to obtain the prevalence of respiratory pathogens and to understand the antibiotic susceptibility patterns of isolates using standard microbiological procedure and the disc-diffusion test. Of the 200 samples screened, 112 (56%) had positive cultures with the dominant bacterial pathogens being Haemophilus influenzae (20%), followed by Streptococcus pneumoniae (15%), Klebsiella pneumoniae (11%), and Staphylococcus aureus (10%). Although 56% of the isolates were recovered from females compared to 44% from males, the difference was not statistically significant (p>0.05). Sixty-seven percent of the pathogens were isolated from the age-group of 10-13 years, 19.6% from the age-group of 14-17 years, and 12.5% from the age-group of 18-21 years. Antibiotic susceptibility testing revealed that gentamicin (92%) and cefuroxime (88.4%) were the most effective antibiotics against the isolates. Generally, susceptibility ranged from 0% to 92% depending on the antibiotic and the species of microorganism. Penicillin had the highest (100%) resistance to all the isolates. The findings revealed that students living in boarding schools in the Buea Municipality were at risk of acquiring upper respiratory tract infections from their peers since the upper respiratory tract of more than 50% of the students was colonized with respiratory pathogens. Although multidrug-resistant strains of organisms were identified, gentamicin and cefuroxime are recommended as the first-line antibiotics of choice against the pathogens. There is, therefore, a need for surveillance of nasopharyngeal carriage of resistant strains of these organisms, especially H. influenzae in unhealthy school children since the vaccine is yet to be introduced in Cameroon. The findings have clinical and epidemiological significance.

Antimicrobial susceptibility of Streptococcus pneumoniae isolated from patients with respiratory tract infections in Thailand.

A total of 400 clinical Streptococcus pneumoniae strains from patients with respiratory diseases were collected from January 2002 to December 2005. In this study, an increased prevalence of penicillin-nonsusceptible S. pneumoniae (PNSP) from 63% in 2002-2003 to 69% in 2004-2005 was found. During 2004-2005, 56% were erythromycin-nonsusceptible S. pneumoniae (ENSP) and 54% were both PNSP and ENSP. The PNSP, ENSP and PNSP+ENSP groups showed similar trends, ie, sensitive to amoxicillin/clavulanate (range 97.2-98.5%), levofloxacin (range 90.7-92.4%), ceftriaxone (range 87.1-89.4%), and ofloxacin (range 64.8-66.1%). Lower levels of susceptibility were detected for azithromycin, clarithromycin, cefdinir, cefprozil, clindamycin, co-trimoxazole, chloramphenicol and tetracycline in penicillin and erythromycin-nonsusceptible strains. Of the macrolide-resistant S. pneumoniae, 55% of strains exhibited the M phenotype and 45% the constitutive MLS(B) phenotype. No pneumococci with the inducible MLS(B) phenotype were detected in Thailand.

Evaluation of the Performances of AdvanSure TB/NTM Real Time PCR Kit for Detection of Mycobacteria in Respiratory Specimens / 대한진단검사의학회지

BACKGROUND: PCR is a widely used method for rapid and accurate diagnosis of mycobacteriosis. The sensitivity and specificity of a real time PCR kit newly developed in Korea were evaluated for detecting mycobacteria in respiratory specimens. METHODS: One hundred twenty nine Mycobacterium tuberculosis (TB) culture positive respiratory specimens (82 AFB stain positive and 47 stain negative specimens) were used for evaluation of the sensitivity. Nine non-tuberculous mycobacteria (NTM) culture positive specimens were also included. For evaluation of the specificity, 48 AFB stain and culture negative respiratory specimens from patients who were initially not fully excluded from mycobacterial diseases (specificity group 1) were used. Other 51 respiratory specimens from patients who were not suspected of mycobacterial diseases were also included (specificity group 2). Real time PCR was performed by using AdvanSure TB/NTM real time PCR Kit (LG Lifescience, Korea) and SLAN real time PCR detection system (LG Lifescience). The target genes of TB and NTM were IS6110 and rpoB, respectively. RESULTS: Among 129 TB culture positive specimens, 82 of 82 AFB stain positive specimens (100%) and 35 of 47 (74.5%) stain negative specimens revealed real time PCR positivity for TB, resulting in sensitivity of 90.7%. Five of nine NTM culture positive specimens resulted in real time PCR positivity for NTM (55.6%). Forty seven of 48 specimens (97.9%) and all 51 specimens (100%) of the specificity group 1 and 2, respectively, were real time PCR negative for TB and NTM. CONCLUSIONS: AdvanSure TB/NTM real time PCR Kit should be useful for detecting TB in respiratory specimens with high sensitivity and specificity.

Antimicrobial susceptibility test of microorganisms isolated from sputum culture of leukaemic patients with lower respiratory tract infections

The development of respiratory infection indicates either a defect in host defenses, exposure to a particularly virulent microorganism, or an ovenwhelming inoculum, as infectious agents gain entry to the lower respiratory tract through aspiration of upper airway resident flora. Better prognosis of patients with leukaemia over the last decade is at least partly due to the possibility of administering more intensive chemotherapy and to the successful introduction a wider array of antimicrobials. To evaluate the antimicrobial susceptibility of the isolates of both leukaemic and non-leukaemic patients with. LRTIs. The present study consisted of 50 adult leukaemic patients, 14 males and 36 females beside other 50 adult non-leukaemic patients, 25 males and 25 females were included, who were admitted to Baghdad Teaching Hospital, through the period from December 2003 through May 2004 with diagnosis of LRTIs. The antimicrobial susceptibility test was done upon the bacterial isolates according to Kirby-Bauer method. The most reliable antibiotics among leukaemic patients [acute myelogenous, acute lymphoblastic, chronic myeloid, chronic lymphocytic] according to antimicrobial susceptibility test, were in cosequence, ciprofloxacin, followed by cefotaxime, then gentamicin and equal influence by ceftriaxone, amikacin, cloxacillin followed by. trimethoprime-sulphamethoxazole, ampicillin, augmentin, finally by erythromycin. On the other spectrum, the most reliable antibiotics among non-leukaemic patients were in consequence ciprofloxacin, followed by trimethopritne-sulphamethoxazole, cefotaxime, an equal effect by ampicillin, gentamicin, and ceftriaxone, followed by augmentin, also an equal effect by cloxacillin and amikacin, finally by erythromycin. Antibiotic susceptibility test should be done for each bacterial isolate in order to prevent the development of progressive microbial resistance

Prevalence of pathogens in cystic fibrosis patients in Bahia, Brazil

INTRODUCTION: Recurrent respiratory infections account for most of the morbidity and mortality of cystic fibrosis patients. MATERIALS AND METHODS: The objective was to determine the prevalence of pathogens isolated from lower respiratory tract secretions in cystic fibrosis patients. In this descriptive observational study, data from 69 patients was collected from medical records. RESULTS: The microorganisms that were identified included 36.2 percent P. aeruginosa, 28.9 percent S. Aureus, 4.3 percent K. pneumoniae, 1.5 percent H. influenzae, 1.5 percent E. coli, 1.5 percent S. maltoophilia, and in 27.5 percent the flora was normal. The prevalence of P. aeruginosa was 83 percent in patients under two years of age, demonstrating early colonization. CONCLUSION: P. aeruginosa and S. aureus were the most prevalent pathogens; there was also early infection/colonization by P. aeruginosa. This information will contribute to improved therapeutic measures for patients of the Bahia Cystic Fibrosis Reference Center

Microbial flora variations in the respiratory tract of mice

A stable microbial system in the respiratory tract acts as an important defense mechanism against pathogenic microorganisms. Perturbations in this system may allow pathogens to establish. In an ecological environment such as the respiratory tract, there are many diverse factors that play a role in the establishment of the indigenous flora. In the present work we studied the normal microbial flora of different areas of the respiratory tract of mice and their evolution from the time the mice were born. Our interest was to know which were the dominant groups of microorganisms in each area, which were the first capable of colonizing and which dominated over time to be used as probiotic microorganisms. Our results show that Gram negative facultatively anaerobic bacilli and strict anaerobic microorganisms were the last ones to appear in the bronchia, while aerobic and Gram positive cocci were present in all the areas of the respiratory tract. The number of facultative aerobes and strict anaerobes were similar in the nasal passage, pharynx instilled and trachea, but lower in bronchia. The dominant species were Streptococcus viridans and Staphylococcus saprophyticcus, followed by S. epidermidis, Lactobacilli and S. cohnii I which were present on every studied days but at different proportions. This paper is the first part of a research topic investigating the protective effect of the indigenous flora against pathogens using the mice as an experimental model.

Bacterial coinfections in infants with bronchiolotis

Although bronchiolitis is a viral infection of the lower respiratory tract in children, yet, antibiotics are widely prescribed in the treatment of those patients. This study investigated the frequency of bacterial co-infection in infants with bronchiolitis, in relation to the clinical signs, X-Ray findings and total and differential leukocytic count. The overall aim was to try to find out simple clinical and/or investigation criteria to rationalize antibiotic therapy in such patients. Sixty-nine patients with clinical diagnosis of bronchiolitis [34 boys and 35 girls] with age range of 1 - 15 months, mean 5.09 +/- 2.84 months were included in the study. Bacterial coinfection was diagnosed by culture of sputum obtained by tracheal aspirate done under direct laryngoscopic visualization, using sterile mucous extractor. Bacteria was isolated from 37.6% of the studied children, Staphylococci, pneumococci, beta hemolytic streptococci were the most common invaders. High and prolonged fever, toxic look, wide spread crepitations on chest auscultation, were more frequently encountered in patients with concomitant bacterial infection, and the difference was statistically significant. Radiological picture of wide spread infiltrates and/or consolidation was a characteristic feature of patients with positive bacterial culture 61.4%, compared to 4.6% in those with no bacterial isolates. Meanwhile, higher total leukocytic count was observed in patients with bacterial coinfection [mean 11.7 +/- 3.8] compared to those with negative culture [9.89 +/- 3.1]. Patients with bacterial coinfection required significantly longer duration of in-patients treatment [7.6 '2.9 days] compared to those without [4.7 +/- 1.9]. Among the above mentioned clinical and investigations criteria, X Ray findings showed high specificity [95.3%], positive and negative predictive values [88.8%, and 80.3%], but is less sensitive in diagnosis of bacterial coinfection [61.5%]. The presence of wide spread crepitations is more sensitive [79.9%], carries high negative predictivity [85%], but less specific [79%]. The presence of both together is highly specific [97.6%], but less sensitive and predictive. It was concluded that careful clinical assessment of patients with bronchiolitis can help to identify candidates for antibiotic therapy, particularly so, if radiological facilities are available

Replicaçäo de Sendai virus em células epiteliais primárias de camundongo / Sendai virus replication in primary epithelial cells of mice

Células epiteliais primárias obtidas do trato respiratório de camundongos jovens foram infectadas com o Vírus Hemaglutinante do Japäo (HVJ, Sendai Virus) e, a progénie viral, tratada ou näo com tripsina foi titulada através do método de Imunofluorescência Indireta. A progénie de Sendai Virus obtida de células epiteliais de camundongo apresentou um título considerável, demonstrando-se que há ativaçäo das partículas virais, capazes de infectar células LLC-MK-2, nas quais, a progénie viral foi titulada

Biología molecular de Bordetella pertussis / Molecular biology of Bordetella pertussis

Bordetella pertusis produce una infección localizada del tracto respiratorio; en los tejidos humanos y en los modelos animales de laboratorio tiene una predilección por el epitelio ciliado. Hay un cierto número de antígenos y toxinas los cuales pueden ser importantes en la patogénesis: aglutinógenos, hemaglutinina filmentosa, factor promotor de la linfocitosis (FPL), adenilatociclasa, toxina termolabil, lipopolisacárido y la citotoxina traqueal. La B. pertussis puede producir también una reacción febril causada por la endotoxina, la atenuación de la respuesta inflamatoria del huésped posiblemente por efecto de la adenilatociclasa, la linfocitosis, leucocitosis, los efectos sobre la homeostasis de la glucosa y la neurotoxicidad producidos por el FPL; sin embargo, no existe un modelo razonable para estudiar la inmunidad local de la tosferina. Los avances recientes en el laboratorio, podrían tener una repercusión sobre la producción de la vacuna y su empleo clínico