Bacteria In Respiratory Infections Research Articles

Nanoparticles in liposomes: a platform for increased antibiotic selectivity in multidrug resistant bacteria in respiratory tract infections.

Antibiotic resistance is a cause of serious illness and death, originating often from insufficient permeability into gram-negative bacteria. Nanoparticles (NP) can increase antibiotic delivery in bacterial cells, however, may as well increase internalization in mammalian cells and toxicity. In this work, NP in liposome (NP-Lip) formulations were used to enhance the selectivity of the antibiotics (3C and tobramycin) and quorum sensing inhibitor (HIPS-1635) towards Pseudomonas aeruginosa by fusing with bacterial outer membranes and reducing uptake in mammalian cells due to their larger size. Poly (lactic-co-glycolic) acid NPs were prepared using emulsion solvent evaporation and incorporated in larger liposomes. Cytotoxicity and uptake studies were conducted on two lung cell lines, Calu-3 and H460. NP-Lip showed lower toxicity and uptake in both cell lines. Then formulations were investigated for suitability for oral inhalation. The deposition of NP and NP-Lip in the lungs was assessed by next generation impactor and corresponded to 75% and 45% deposition in the terminal bronchi and the alveoli respectively. Colloidal stability and mucus-interaction studies were conducted. NP-Lip showed higher diffusion through mucus compared to NPs with the use of nanoparticle tracking analyzer. Moreover, the permeation of delivery systems across a liquid-liquid interface epithelial barrier model of Calu-3 cells indicated that NP-Lip could cause less systemic toxicity upon in-vivo like administration by aerosol deposition. Monoculture and Pseudomonas aeruginosa biofilm with Calu-3 cells co-culture experiments were conducted, NP-Lip achieved highest toxicity towards bacterial biofilms and least toxicity % of the Calu-3 cells. Therefore, the NP- liposomal platform offers a promising approach for enhancing antibiotic selectivity and treating pulmonary infections.

Diagnostic strategy of metagenomic next-generation sequencing for gram negative bacteria in respiratory infections

ObjectiveThis study aims to identify the most effective diagnostic method for distinguishing pathogenic and non-pathogenic Gram-negative bacteria (GNB) in suspected pneumonia cases using metagenomic next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) samples.MethodsThe effectiveness of mNGS was assessed on BALF samples collected from 583 patients, and the results were compared with those from microbiological culture and final clinical diagnosis. Three interpretational approaches were evaluated for diagnostic accuracy.ResultsmNGS outperformed culture significantly. Among the interpretational approaches, Clinical Interpretation (CI) demonstrated the best diagnostic performance with a sensitivity of 87.3%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 98.3%. CI’s specificity was significantly higher than Simple Interpretation (SI) at 37.9%. Additionally, CI excluded some microorganisms identified as putative pathogens by SI, including Haemophilus parainfluenzae, Haemophilus parahaemolyticus, and Klebsiella aerogenes.ConclusionProper interpretation of mNGS data is crucial for accurately diagnosing respiratory infections caused by GNB. CI is recommended for this purpose.

Isolation of non-fermenting Gram negative bacteria in respiratory tract infections

Respiratory tract infections are the most common diseases that are associated with mortality and morbidity. They are often misdiagnosed due to its nonspecific presentation in clinical settings. The risk factors of RTI vary geographically and timely(1). So it is important to evaluate more for RTI causative agents.The non-fermentative Gram negative bacilli (NFGNB) are often associated with RTI. The NFGNB are a group of several different aerobic, non-sporing, Gram negative bacilli that either unable to utilize carbohydrates as a source of energy or withhold them through metabolic pathways other than the fermentation. The study was undertaken to identify various non- fermenters by additional conventional tests, isolated from patients having respiratory tract infection in department of Microbiology, SVPPGIP and SCBMCH Medical college, a Tertiary Care Center, Odisha. Our study also line up the singnificant role of NFGNB as respiratory pathogens.391 (14.6 %) non-fermenters were isolated from 2678 clinical specimens. Out of which NFGNB(391 samples), a total of 143 (36.57%) were from various respiratory samples were included in this study and were isolated on MacConkey and blood agar plates incubated at 35°C for 24-48 hours. Patients mostly belonged to age group of 65 to 80 years and were 96(67%)male. complex 67(46.8%) was the commonest isolate followed by 56(39.1%). While other NFGNB like were isolated in few respiratory samples.The most effective antibiotics were Tigecycline and Polymyxin B/ Colistin, however majority of them showed multidrug resistance.

Analysis of characteristics of bacteria in respiratory tract infection in 2013-2016 in Heibei 3A hospital: a single-center report of 7 497 patients

To analyze the changes and characteristics of respiratory tract bacteria in Hebei 3A Hospital, and to provide new rationale for clinical diagnosis and treatment. A single-center retrospective analysis was conducted. 7 497 patients with respiratory tract infection admitted to Hebei Chest Hospital from January 2013 to December 2016 were enrolled. Deep sputum was collected, and the bacterial cultures and susceptibility analysis was conducted in sputum and upper respiratory secretions were collected by fiberoptic bronchoscopy. A total of 7 497 patients with respiratory tract infection were enrolled in the study, and 11 909 strains of 13 kinds of dominant pathogens were isolated. The dominant pathogens for respiratory tract infection were Monilia albican (23.7%), Klebsiella pneumoniae (12.9%), Pseudomonas aeruginosa (11.6%), Escherichia coli (9.5%), Candida glabrata (9.1%), Acinetobacter baumanii (7.9%), Aspergillus (6.7%), Stenotrophomonas maltophilia (4.5%), coagulase negative Staphylococcus (3.7%) and some species of Pseudomonas (3.7%), Staphylococcus aureus (3.0%), Aerobacter cloacae (1.9%), and Candida tropicalis (1.8%). A total of 6 198 strains of 7 kinds of Gram negative (G-) bacilli infection dominant pathogens accounts for 52.0% of all infections, Klebsiella pneumonia (24.8%), Pseudomonas aeruginosa (22.3%), Escherichia coli (18.2%) and Acinetobacter baumanii (15.3%) were the main pathogens, and increased year by year. Susceptibility analysis showed that the preferred antibiotics for G- bacteria were carbapenems, followed by risperidone, sulbactam, cefepime, amikacin, and the third generation of cephalosporins. A total of 798 strains of 2 kinds of Gram positive (G+) bacilli infection dominant pathogens accounted for 6.7% of all infections, were coagulase negative Staphylococcus (54.8%) and Staphylococcus aureus (45.2%), each had changed little by year. Susceptibility analysis showed that G+ bacteria were sensitive to glycopeptides, followed by cefoxitin, cotrimoxazole, the tetracyclines, quinolones, azithromycin, erythromycin and so on. The advantages of 4 species of fungi were 4 913 strains, accounted for all of the 41.3% strains, with 57.5% of Candida albicans, and the trend was increasing year by year. Susceptibility analysis results showed that the antifungal susceptibility of dominant fungi were higher. G- bacilli is still the main source of infection, and showed an upward trend year by year. Fungal infection rate cannot be ignored, and we must pay attention to fungal infection incentives. We should strengthen the rational use of antibiotics.

Antibacterial Susceptibility of Klebsiella pneumoniae Isolates from Respiratory Tract Infections to Honey and Lemon

Aims: To assess the effectiveness of lemon and/or honey on some causative agents of Respiratory Tract Infections, Isolation and identification of some infectious bacteria of respiratory tract infections, Collection of pure honey and lemon fruits, Determination of the inhibitory activities of honey, lemon and honey/lemon mixture at varied concentrations on the bacterial isolates by agar diffusion and broth dilution techniques, Evaluation of the rate of kill of the bacterial isolates by the agents (honey and lemon) and Comparative analysis of the susceptibility pattern of the bacterial isolates to the honey and lemon separately and in combination. Study Design: Isolation, identification and antibiotic susceptibility determination of the test Klebsiella pneumoniae isolates, Zones of inhibition, Minimum Inhibitory and Bactericidal Concentrations and Rate of kill determination. Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University Teaching Hospital (A. B. U. T. H.), Zaria, University Hospital Services (U. H. S.) Samaru Campus Ahmadu Bello University (A. B. U.), Zaria, between March 2012 and April 2013. Methodology: Agar well diffusion and broth dilution methods were employed to ascertain Original Research Article Annual Research & Review in Biology, 4(4): 625-637, 2014 626 degree of susceptibility of the isolates to honey and/or lemon, and the standard antibiotics. Minimum Inhibitory Concentrations and Minimum Bactericidal Concentrations were carried out. Rate of Kill was also carried out to know the death/survival rate of the bacterial isolates after exposure to the agents. Results: Mean zones of inhibition (mm) of 14-32 (Ceftriaxone), 7-27 (Gentamicin), 8-35 (Amoxicillin-Clavulanic acid), 12-27 (Levofloxacin), 7-21 (Azithromycin), 10-23 (100% v/v Honey), 10-24 (100% v/v Lemon), and 19-26 (Honey/Lemon mixture) were obtained. However, the Minimum Inhibitory Concentrations range between 1.95-125 μg/ml (Ceftriaxone), 1.56-100 μg/ml (Gentamicin), 3.91-125 μg/ml (Amoxicillin-Clavulanic acid), 0.98-15.6 μg/ml (Levofloxacin), 3.13-100 μg/ml (Azithromycin), 20-65 μg/ml v/v (Honey), 15-35 μg/ml v/v (Lemon), 15-35 μg/ml (Honey/Lemon mixture). Furthermore, for the rate of kill; Lemon, Honey and Lemon mixture (20 μg/ml) effected complete killing at 120 minutes and 240 minutes respectively. Therefore, it was observed that lemon, honey and lemon mixture, Ceftriaxone, Levofloxacin and Gentamicin showed higher antibacterial activity. While Amoxicillin-Clavulanic acid and Azithromycin had less antibacterial activity. At Pvalue P≥0.05 there is significant difference between Honey and Lemon mixture and Honey, but not with lemon. Conclusion: It was observed that lemon, honey and lemon mixture, Ceftriaxone, Levofloxacin and Gentamicin showed higher antibacterial activity. While AmoxicillinClavulanic acid and Azithromycin had less antibacterial activity. Better bactericidal activity was observed with Lemon and the mixture of Honey and Lemon than the Honey alone. This research therefore scientifically approves the use of Honey and Lemon as an alternative medicine by the populace in the treatment of respiratory tract infections.

RECENT TRENDS IN INCIDENCE OF RESPIRATORY TRACT PATHOGENS AND ANTIMICROBIAL SUSCEPTIBILITIES OF HAEMOPHIL US INFL UENZAE, STREPTOCOCCUS PNEUMONIAE AND MORAXELLA CATARRHALIS ISOLATED IN 1994 AND 1995

The incidence of pathogenic bacteria in respiratory tract infections in 1994 and 1995 was investigated using quantitative cultures of sputa from patients with the infections in our department. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis were isolated at high rates (70.5% in 1994 and 73.8% in 1995) from the specimens of out-patients, and the incident rates were similar to the past data. The antimicrobial susceptibilities of these three pathogens were examined with the agar dilution method. The incidence of penicillin (Pc) resistant S. pneumoniae against which MIC of Pc-G was higher than 0.125 microgram/ml was markedly increased from 24% in 1994 to 34.9% in 1995. Most of the Pc resistant isolates were also resistant to other antibiotics including erythromycin, minocycline and tosufloxacin. Serotype of strains against which MIC of Pc-G was higher than 1.0 microgram/ml was 19. The ratios of beta-lactamase-producing strains among H. influenzae isolated in 1994 and 1995 were 20 and 15.8%, respectively, which were slightly higher than those in the past. One quinolone resistant strain was isolated in this study. Although the ratio of beta-lactamase-producing strains among M. catarrhalis was as high (96.7%) as in the past, no increased resistance against the drugs examined was observed.

Levofloxacin concentrations in serum, sputum and lung tissue: evaluation of its efficacy according to breakpoint

The levels of levofloxacin (LVFX) in the serum, sputum and lung tissue were measured by a high-performance liquid chromatography method, and the penetration ratio of LVFX into respiratory tissue was investigated. The subjects of this study were 23 patients under pulmonectomy or brochoscopy. LVFX at the dose of 200 mg was given orally and specimens were collected as follows; serum at 2, 3 and 5 hours after, sputum at 2 hours after, and lung tissue at 3 and 5 hours after the administration, respectively. The mean level of LVFX in lung tissue at 3 hours was 3.91 +/- 2.33 micrograms/g, and those in sputum and in serum at 2 hours were 0.71 +/- 0.63 and 2.08 +/- 1.01 micrograms/ml, respectively. A very strong correlation was demonstrated between the level of LVFX in lung tissue and that in serum (p < 0.0001), but correlation between those in sputum and in serum was not significant. The penetration ratio of LVFX into lung tissue was 217.2% and that into sputum was 4.05%. Based on the results of this study, the breakpoints (BPs) of LVFX for pneumonia and chronic respiratory tract infections were calculated to be 4 micrograms/ml and 1 microgram/ml, respectively. It was concluded that penetration of LVFX into lung tissue was satisfactory, and the tissue level of LVFX exceeded greatly the MIC90s against the typical pathogenic bacteria of respiratory tract infections. Taking the excellent BP for pneumonia, 4 micrograms/ml, into consideration, it was thought that LVFX is an effective antibacterial agent against pneumonia and other respiratory tract infections.

Oral Health and the Stroke Survivor

Abstract This module includes a narrated PowerPoint with embedded video clips, as well as a non-narrated PowerPoint presentation, both of which provide a review of the numerous effects a cerebrovas...

Role of oral bacteria in respiratory infection.

An association between oral conditions such as periodontal disease and several respiratory conditions has been noted. For example, recent evidence has suggested a central role for the oral cavity in the process of respiratory infection. Oral periodontopathic bacteria can be aspirated into the lung to cause aspiration pneumonia. The teeth may also serve as a reservoir for respiratory pathogen colonization and subsequent nosocomial pneumonia. Typical respiratory pathogens have been shown to colonize the dental plaque of hospitalized intensive care and nursing home patients. Once established in the mouth, these pathogens may be aspirated into the lung to cause infection. Other epidemiologic studies have noted a relationship between poor oral hygiene or periodontal bone loss and chronic obstructive pulmonary disease. Several mechanisms are proposed to explain the potential role of oral bacteria in the pathogenesis of respiratory infection: 1. aspiration of oral pathogens (such as Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, etc.) into the lung to cause infection; 2. periodontal disease-associated enzymes in saliva may modify mucosal surfaces to promote adhesion and colonization by respiratory pathogens, which are then aspirated into the lung; 3. periodontal disease-associated enzymes may destroy salivary pellicles on pathogenic bacteria to hinder their clearance from the mucosal surface; and 4. cytokines originating from periodontal tissues may alter respiratory epithelium to promote infection by respiratory pathogens.

Causative bacteria of respiratory tract infections in Kuwait by quantitative culture of sputum

To determine the bacterial etiology of lower respiratory tract infections in Kuwait, we performed quantitative culture of sputum and measured the susceptibilities of the isolated bacteria against different antibiotics. A total of 140 sputum samples were collected for a period of 14 months for the study. Single and multiple pathogens as a cause of infection were isolated from 55 and 15 samples, respectively. A total of 53.8% of Streptococcus pneumoniae were penicillin-resistant and 52% and 57% of Hemophilus influenzae and Moraxella catarrhalis were β-lactamase positive, respectively. We concluded that the major pathogens of respiratory tract infections in Kuwait were H. influenzae, M. catarrhalis, S. pneumoniae, and Pseudomonas aeruginosa, and there was an increased resistance among the isolated bacteria against commonly used antibiotics.

The incidence of respiratory tract pathogens and antimicrobial susceptibilities of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis isolated between 1990 and 1993.

Using a quantitative culture of sputum, the incidence of pathogenic bacteria in respiratory infection in our laboratory between 1990 and 1993 were investigated. While Haemophilus influenzae, Streptococcus pneumoniae and Moraxella (Branhamella) catarrhalis were isolated at high rates (67-78%) from the specimens of outpatients throughout the study period, the incidence of S pneumoniae has increased gradually. The antimicrobial susceptibilities of these three pathogens were examined with the agar dilution method. A marked increase of penicillin (PC) resistant S. pneumoniae (MIC > or = 0.1 microgram/ml) was observed with a resistance rate of 2.1% in 1990 and 25% in 1993. Resistance to erythromycin (EM, MIC > or = 1.56 micrograms/ml) was 8.5% in 1990 but then increased to 34% in 1992. Most of the PC resistant isolates were resistant to multidrugs such as EM, minocycline and clindamycin. The MICs of all beta-lactams examined for S. pneumoniae increased along with the MICs of PC, though the level varied between drugs. The rates of beta-lactamase positive H. influenzae gradually decreased, being 14.3% in 1990 and 7.4% in 1993, whereas those of M. (B) catarrhalis were consistently high (> 90%) every year. In addition to beta-lactamase production, the emergence of strains of H. influenzae and M. (B) catarrhalis resistant to new quinolone drugs should be noted.

Susceptibilities of bacteria isolated from patients with respiratory infectious diseases to antibiotics (1990)

These investigations have been continued since 1981. In this year the isolation frequencies and sensitivities to antibiotics were investigated for 654 bacterial strains isolated from respiratory tract infections in 20 institutions during the period of October 1990 to September 1991. Among Staphylococcus aureus isolated from inpatients, many were methicillin-resistant S. aureus (MRSA), and the frequency of their isolation was 56.3% for inpatients and 4.3% for outpatients. Of the relation to antibiotic administration, the isolation frequency of MRSA before administration of antibiotics was 19.6% (10/51), and after administration was 75.0% (27/36). The sensitivities of S. aureus to imipenem and clindamycin (MIC80) decreased from 0.2 microgram/ml to 64 micrograms/ml and from 0.2 micrograms/ml to 128 micrograms/ml, respectively. We investigated year to year changes in the backgrounds of patients with respiratory tract infections. Bacterial pneumonia was 31.6% among respiratory tract infections in the period of the study, this trend has increase from 1989. Frequencies of different etiological bacteria in respiratory tract infections did not change appreciably from year to year, and S. aureus, Streptococcus pneumoniae and Pseudomonas aeruginosa were the most showing some frequent pathogens.

Identification of strains on recurrent Haemophilus influenzae infections in patients with chronic respiratory tract infections

Nontypable Haemophilus influenzae is one of the most important pathogenic bacteria in respiratory tract infections. H. influenzae is most frequently associated with recurrent infections in chronic respiratory tract infections (CRTIs). It is known that H. influenzae often reemerges after the antibiotic treatment has been stopped. We analyzed serotype, biotype, and the OMP patterns of H. influenzae isolates from sputum of CRTIs patients to determine whether an exacerbation is caused by an identical H. influenzae strain, or by a new H. influenzae strain. One hundred eighty nine strains of H. influenzae were obtained from 124 exacerbation from 24 patients. The first and second isolates were identical in 23 out of 33 exacerbations (< or = 15-days interval between each exacerbation) and also in 22 out of 34 exacerbations (15 < days but < or = 30-days interval between each exacerbation). This is called early recurrence. In contrast, the first and second isolates were different in 28 out of 34 exacerbations (> 30-days interval between each exacerbation). This is called late recurrence. These results suggest that early recurrence and late recurrence of recurrent H. influenzae infections occur in a different mechanism.

Direct and Indirect Pathogenicity of ??-Lactamase-Producing Bacteria in Respiratory Tract Infection in Children

A recent increase in the incidence of beta-lactamase-producing aerobic and anaerobic bacteria in upper respiratory tract infection has been associated with an increase in the failure rate of penicillin treatment of these infections. Experimental evidence for this correlation has been reported by many investigators, who have described the sheltering of susceptible pathogens by beta-lactamase-producing organisms as 'indirect pathogenicity'. The organisms implicated in mixed infections that cooperate are Staphylococcus aureus, Haemophilus influenzae, Branhamella (Moraxella) catarrhalis and Bacteroides spp., which are pathogenic and also normal oropharyngeal inhabitants. Since these bacteria exhibit both direct and indirect pathogenicity, effective treatment requires administration of antimicrobial therapy active against all microorganisms present in mixed infection. Oral third generation cephalosporins, which are resistant to enzymatic hydrolysis, seem to be suitable initial therapy.

Respiratory superinfections after the use of third-generation cephem antibiotics.

This paper is a report on our studies on superinfections in respiratory tract infections treated during the years 1981-1984. The isolated strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Streptococcus faecium and glucose non-fermentative gram-negative rods such as Pseudomonas aeruginosa were resistant to third-generation cephem antibiotics. These organisms proved to be widely distributed in hospitals and were frequently isolated from the sputum, excised lung and cardiac blood. The colonization of the sputum by bacteria in respiratory tract infections before, during and after treatment with third-generation cephem antibiotics revealed a tendency for these organisms to appear after treatment. Among the gram-positive cocci, S. faecium was most resistant to these antibiotics, followed by S. faecalis, S. epidermidis and S. aureus in that order. The incidence of resistant isolates in 1984 exceeded that in 1983, suggesting an annual increase in resistant bacteria.

Inhalation Experiments on Influenza and Pneumonia, and on the Importance of Spray-Borne Bacteria in Respiratory Infections

Inhalation Experiments on Influenza and Pneumonia, and on the Importance of Spray-Borne Bacteria in Respiratory Infections

Inhalation Experiments on Influenza and Pneumonia, and on the Importance of Spray-Borne Bacteria in Respiratory Infections

Inhalation Experiments on Influenza and Pneumonia, and on the Importance of Spray-Borne Bacteria in Respiratory Infections