scholarly journals Timber-colonizing gram-negative bacteria as potential causative agents of respiratory diseases in woodworkers

Author(s):  
Angelina Wójcik-Fatla ◽  
Barbara Mackiewicz ◽  
Anna Sawczyn-Domańska ◽  
Jacek Sroka ◽  
Jan Siwiec ◽  
...  

Abstract Occurrence Gram-negative bacteria occur commonly in the inner tissues of stored coniferous and deciduous timber, showing a marked variation in numbers. The greatest maximal numbers are found in the sapwood of coniferous timber. The common constituents of the Gram-negative biota are potentially pathogenic species of Enterobacteriaceae family of the genera Rahnella, Pantoea, Enterobacter, and Klebsiella. The air of wood-processing facilities is polluted with the wood-borne Gram-negative bacteria and produced by them endotoxin, as demonstrated worldwide by numerous studies. Effects There are three potential pathways of the pathogenic impact of wood-borne Gram-negative bacteria on exposed woodworkers: allergic, immunotoxic, and infectious. Allergic impact has been underestimated for a long time with relation to Gram-negative bacteria. Hopefully, the recent demonstration of the first documented case of hypersensitivity pneumonitis (HP) in woodworkers caused by Pantoea agglomerans which developed in extremely large quantities in birch sapwood, would speed up finding of new wood-related cases of HP caused by Gram-negative bacteria. The second pathway is associated with endotoxin, exerting strong immunotoxic (excessively immunostimulative) action. It has been demonstrated that endotoxin is released into wood dust in the form of nano-sized microvesicles, by peeling off the outer membrane of bacteria. Endotoxin microvesicles are easily inhaled by humans together with dust because of small dimensions and aerodynamic shape. Afterwards, they cause a nonspecific activation of lung macrophages, which release numerous inflammatory mediators causing an inflammatory lung reaction, chest tightness, fever, gas exchange disorders, and bronchospasm, without radiographic changes. The resulting disease is known as “Organic Dust Toxic Syndrome” or “toxic pneumonitis.” The potential third pathway of pathogenic impact is infection. The suspected species is Klebsiella pneumoniae that may occur commonly in wood dust; however, until now this pathway has not been confirmed. Conclusion Summarizing, Gram-negative bacteria-inhabiting timber should be considered, besides filamentous fungi and actinobacteria, as important risk factors of occupational disease in woodworkers that could be either HP with allergenic background or toxic pneumonitis elicited by endotoxin.

2021 ◽  
Author(s):  
Mradul Kumar Daga ◽  
Govind Mawari ◽  
Saman Wasi ◽  
Naresh Kumar ◽  
Udbhav Sharma ◽  
...  

Abstract Objective To understand the pattern and types of healthcare associated infections (HAI) at our healthcare facility, and to determine the common causative agents and their antibiotic susceptibility profile. Methods One hundred consecutive patients diagnosed with HAI were enrolled and monitored; the causative organisms isolated on culture were recorded and their sensitivity profile was generated. Results Of the 100 patients diagnosed with HAI (mean age ± SD being 42 ± 17 years), there were a total of 110 hospital acquired infections with 10 patients having two infections each. Out of 100 patients with HAI, 69 patients had ventilator associated pneumonia (VAP), 21 patients had catheter associated urinary tract infection (CAUTI) patients, and 20 patients had central line associated bloodstream infection (CLABSI). There were 10 patients with both VAP and CAUTI. All of the HAIs were device associated. A total of 76 pathogens were isolated on culture. No organism was isolated in 40 HAI. Majority (94.7%) of the organisms isolated from HAIs were gram-negative bacteria and all were multidrug resistant. Seventy-seven of the enrolled patients expired while 23 were discharged from the hospital Conclusions Our study demonstrated that HAIs occur in patients of all age groups; younger patients are not spared. Majority of the HAIs were caused by multidrug resistant gram-negative bacteria and were associated with high patient mortality. Acinetobacter species was the most common organism associated with HAI.


2013 ◽  
Vol 58 (2) ◽  
pp. 851-858 ◽  
Author(s):  
Nicola Petrosillo ◽  
Maddalena Giannella ◽  
Massimo Antonelli ◽  
Mario Antonini ◽  
Bruno Barsic ◽  
...  

ABSTRACTA colistin-glycopeptide combination (CGC) has been shownin vitroto be synergistic against multidrug-resistant Gram-negative bacteria (MDR GNB), especiallyAcinetobacter baumannii, and to prevent further resistance. However, clinical data are lacking. We carried out a retrospective multicenter study of patients hospitalized in intensive care units (ICUs) who received colistin for GNB infection over a 1-year period, to assess the rates of nephrotoxicity and 30-day mortality after treatment onset among patients treated with and without CGC for ≥48 h. Of the 184 patients treated with colistin, GNB infection was documented for 166. The main causative agents were MDRA. baumannii(59.6%), MDRPseudomonas aeruginosa(18.7%), and carbapenem-resistantKlebsiella pneumoniae(14.5%); in 16.9% of patients, a Gram-positive bacterium (GPB) coinfection was documented. Overall, 68 patients (40.9%) received CGC. Comparison of patients treated with and without CGC showed significant differences for respiratory failure (39.7% versus 58.2%), ventilator-associated pneumonia (54.4% versus 71.4%), MDRA. baumanniiinfection (70.6% versus 52%), and GPB coinfection (41.2% versus 0%); there were no differences for nephrotoxicity (11.8% versus 13.3%) and 30-day mortality (33.8% versus 29.6%). Cox analysis performed on patients who survived for ≥5 days after treatment onset showed that the Charlson index (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.01 to 1.44;P= 0.001) and MDRA. baumanniiinfection (HR, 2.51; 95% CI, 1.23 to 5.12;P= 0.01) were independent predictors of 30-day mortality, whereas receiving CGC for ≥5 days was a protective factor (HR, 0.42; 95% CI, 0.19 to 0.93;P= 0.03). We found that CGC was not associated with higher nephrotoxicity and was a protective factor for mortality if administered for ≥5 days.


2020 ◽  
Vol 17 (4) ◽  
pp. 789-795
Author(s):  
M. A. Kovalevskaya ◽  
O. V. Donkareva ◽  
O. A. Pererva

Long-term conjunctival infections are challenging for the outpatient ophthalmologist. This is due to significant changes in microflora towards resistant gram-negative bacteria. Long-term conjunctival infections are challenging for the outpatient ophthalmologist. This is due to a significant change in microflora towards resistant gram-negative bacteria. The above studies are based on microbial associations, which are the causes of inflammatory processes, conjunctiva and cornea.Purpose: to increase the effectiveness of the diagnosis and treatment of chronic specific inflammatory diseases of the organs of vision.Patients and methods. The study was conducted in patients with chlamydial infection (n = 589) and included chronic conjunctival infections lasting more than 4 weeks, follow-up of patients with partners, family members for 3 or more years. Results. The study was carried out in patients with chlamydial infection (n = 589) and with chronic infectious diseases that lasted more than 4 weeks, following patients and family members for 3 or more years. During this period, we performed more than 3 studies for each patient — for diagnostic laboratory studies and 2 consecutive controls 1 and 2 months after treatment, mixed infection was detected in 256 people (10 %), the proportion of women was 20–30 years is 67 %, men — 51 %. In 27 % of cases, communities of Ch. trachomatis and Ureaplasma parvum as leading causative agents of the eye infections.Conclusions. Chlamydia is most often found together with Ureaplasma parvum (27 % of cases among mixed infections). Treatment of various forms of chlаmidia infection is carried out with the help of “Floxal” (0.3 % ofloxacin — drops and ointment). 


Author(s):  
Kh. S. Khaertynov ◽  
V. A. Anokhin ◽  
S. V. Khaliullina ◽  
S. A. Lubin ◽  
N. V. Dontsova ◽  
...  

Purpose. To evaluate clinical and epidemiological features of neonatal sepsis and assess the impact of organ dysfunction on its outcome.Characteristics of children and research methods. The authors carried out a retrospective analysis of 66 patients with neonatal sepsis hospitalized to the neonatal intensive care unit of the Kazan City Children’s Hospital No. 1 from 2013 to 2017. The diagnosis was based on the development of a systemic inflammatory response syndrome, an increase in C-reactive protein concentration in the blood more than 1 mg/dl, the presence of one or more foci of infection, the development of organ dysfunction and the isolation of the microorganism from venous blood. Bacteremia was a mandatory inclusion criterion.Results. In the most cases (54.5%) neonatal sepsis was caused by gram-negative bacteria. 41 and 4.5% of cases were caused by gram-positive bacteria and fungi, respectively. Among the gram-negative bacteria, the main causative agents of sepsis were Klebsiella pneumoniae (27 cases, 41%), among the gram-positive bacteria –staphylococci (24 cases, 36.5%). Fungal sepsis was caused by Candida kruzei (2 cases) and Candida albicans (1 case). In 11 (17%) cases there was a dysfunction of a single organ, in 31 (47%) cases – dysfunction of 2 organs and in 24 (36%) cases – dysfunction of more than 2 organs. The most common impairments were respiratory dysfunction (86%) and hemostatic disorders in the form of thrombocytopenia (58%). Neonatal sepsis was fatal in 11 (17%) cases. It was found that the multiple organ dysfunction was associated with a risk of death (odds ratio – OR = 29.3; 95% CI 3.4–249.7). Among the signs of organ dysfunction, coma (OR = 30.8; 95% CI 3.0–316.6), elevated blood lactate level of more than 5 mmol/l (OR = 22.1; 95% CI 3.5–139,6) and a low platelet count of less than 50 · 109/l (OR = 5; 95% CI 1.2–21.3) had the prognostic significance.Conclusion. Modern neonatal sepsis has a diverse etiology with gram-negative bacteria as causative agents in half of the cases. Despite modern treatment methods, neonatal sepsis remains a formidable infectious pathology. The risk of fatal outcome is associated with organ dysfunction. Coma, elevated blood lactate level and severe thrombocytopenia are the most significant predictors of fatal outcome in neonatal sepsis.


2020 ◽  
Vol 65 (9) ◽  
pp. 562-566
Author(s):  
I. V. Shipitsyna ◽  
E. V. Osipova ◽  
O. A. Astashova ◽  
D. S. Leonchuk

The annual monitoring of the species composition of the causative agents of osteomyelitis, the identification of antibiotic-resistant strains, the study of the species composition of associations of microorganisms, their adhesive activity will prevent the spread of infection. Analyze the spectrum of the leading causative agents of osteomyelitis, their antibiotic sensitivity, and also the adhesive activity of the identified bacterial associations. A microbiological analysis of 2197 smears of adult patients with various etiological forms of osteomyelitis who were treated in the departments of the purulent center of the FSBI «NMRCTO» of the RF Ministry of Health in 2019. The spectrum of pathogenic microflora, sensitivity to standard antibacterial drugs used in the clinic was studied. The biofilm-forming ability of associations of microorganisms was investigated. According to the conducted microbiological monitoring for 2019, the microflora spectrum for osteomyelitis is diverse, the main pathogens are S. aureus, S. epidermidis, P. aeruginosa, K. pneumoniae, Enterococcus sp. A high percentage of isolation of microbial associations was noted, most often mix cultures of gram-positive and gram-negative bacteria. Bacterial associations: S. aureus + P. aeruginosa, S. aureus + S. marcescens, S. aureus + A. baumannii, S. epidermidis + E. cloacae - actively formed a biofilm on the surface of polystyrene plates, and the adhesive potential depended on interstrain relations in the composition of the formed biofilm. Among Gram-negative microflora, multiresistant strains prevail, among Gram-positive microflora - a high percentage of methicillin-resistant Staphylococci. When analyzing the antibiotic sensitivity of the isolated microorganisms, a high percentage of resistant strains is noted. So, with respect to enterobacteria, β-lactam antibiotics, drugs from the group of aminoglycosides, turned out to be ineffective. Among non-fermenting gram-negative bacteria, A. baumannii strains had multiple antimicrobial resistance. Among gram-positive microorganisms, a high percentage of isolation of methicillin-resistant staphylococci was noted. The specificity of the course of the disease and measures aimed at eliminating the pathogen depend on the species composition in the focus of infection. The study of the etiological structure of osteomyelitis, the monitoring of the antibiotic resistance of pathogens and their persistent potential, makes it possible to adopt sound tactics of conservative and surgical treatment.


2015 ◽  
Vol 61 (4) ◽  
pp. 341-346 ◽  
Author(s):  
Gabriel de Deus Vieira ◽  
Hallan Rodrigues Mendonça ◽  
Thaianne da Cunha Alves ◽  
Danilo Fernandes de Oliveira Araújo ◽  
Mauro Lopes da Silveira Filho ◽  
...  

SummaryObjective:to evaluate the cases of wound infections in orthopedic postoperative period.Methods:postoperative patients who developed infection during the period from November 2012 to November 2013 were studied. Secretions were collected during surgery using sterile swabs, and sent for microbiological analysis.Results:during the period analyzed, 38 surgical procedures progressed to infection. The type of surgery presenting the largest number of infections was osteosynthesis, in 36 (94.7%) patients. Among the materials used, 18 (36%) surgeries that used external fixator were infected, and 17 (34%) using plate. The species of bacteria that caused the largest number of infections were Staphylococcus aureus, infecting 16 (43.9%) patients, followed by Acinetobacter baumannii, which infected four (10.5%) patients. Regarding the resistance profile of Gram-positive strains to antibiotics, 100% of Staphylococcus aureus strains were susceptible to vancomycin and 31.3%, to ceftriaxone. As for the Gram-negative bacteria, 100% of Acinetobacter baumannii strains were resistant to ceftriaxone, gentamicin and imipenem.Conclusion:infection control in the postoperative period is necessary, using antibiotics correctly and consciously, avoiding resistance of bacterial agents.


1981 ◽  
Vol 44 (8) ◽  
pp. 633-647 ◽  
Author(s):  
JON J. KABARA

Now that energy has become a world problem, cheap, effective chemical preservation is critical. This discussion forwards a new concept in food preservation. The concept is based on a ‘systems’ approach, using three common foodstuffs: monolaurin, food-grade phenolics and chelator, three multifunctional food materials, whose history as potential preservatives is reviewed. Although monolaurin (Lauricidin) is a Generally Recognized As Safe chemical, its use as part of a ‘preservative system’ is new. Comparisons of its germicidal activity by investigators have shown it to be more effective than proprionates, benzoates and even sorbic acid. The common antioxidants, tert-butylhydroxytoluene (BHT) or tert-butylhydroxyanisole (BHA) have been shown since 1967 to affect a number of different microorganisms, including viruses. The chelator ethylenediamineacetate (EDT A) has weak biocidal activity on its own but can potentiate the effect of the first two biocidal agents, particularly against gram-negative bacteria. The three common food chemicals therefore become part of a ‘preservative system’. The amount and ratio of one to the other is determined by the specific need for microbiological protection.


2007 ◽  
Vol 51 (11) ◽  
pp. 3908-3914 ◽  
Author(s):  
Mart Krupovič ◽  
Rimantas Daugelavičius ◽  
Dennis H. Bamford

ABSTRACT Polymyxin B (PMB) is a cationic antibiotic that interacts with the envelopes of gram-negative bacterial cells. The therapeutic use of PMB was abandoned for a long time due to its undesirable side effects; however, the spread of resistance to currently used antibiotics has forced the reevaluation of PMB for clinical use. Previous studies have used enteric bacteria to examine the mode of PMB action, resulting in a somewhat limited understanding of this process. This study examined the effects of PMB on marine pseudoalteromonads and demonstrates that the frequently accepted view that “what is true for Escherichia coli is true for all bacteria” does not hold true. We show here that in contrast to the growth inhibition observed for enteric bacteria, PMB induces lysis of pseudoalteromonads, which is not prevented by high concentrations of divalent cations. Furthermore, we demonstrate that a high membrane voltage is required for the interaction of PMB with the cytoplasmic membranes of pseudoalteromonads, further elucidating the mechanisms by which PMB interacts with the cell envelopes of those gram-negative bacteria.


1914 ◽  
Vol 19 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Charles Krumwiede ◽  
Josephine S. Pratt

Gentian violet and allied anilin dyes have a similar influence on bacterial growth, dividing bacteria into two groups corresponding in general to their reaction to the Gram stain. Among Gram-negative bacteria a strain is occasionally encountered which will not grow on violet agar, differentiating it from other members of the same species or variety. The reaction is quantitative, although the quantitative character is more marked with some species than with others. The streptococcus-pneumococcus group differ from other Gram-positive bacteria in their ability to grow in the presence of amounts of dye sufficient to inhibit the other species. The dysentery bacillus group shows marked variation in the presence of dyes. In the case of fuchsin the variation approaches closely a specific difference between the dysentery and paradysentery groups. The variations of the latter groups with other dyes show no correlation with the common differential characteristics. A closer study might reveal variations in other characteristics which would parallel the different reactions to dyes. Decolorization with sodium sulphite robs the dyes of some of their inhibitive powers.


2020 ◽  
Vol 74 (2) ◽  
pp. 3-8
Author(s):  
I.N. Shishimorov ◽  
◽  
O.V. Magnitskaya ◽  
O.V. Shatalova ◽  
N.F. Shaposhnikova ◽  
...  

The review addresses the main issues related to the rational pharmacotherapy of urinary tract infection (UTI). UTIs are a common and important clinical problem in children. Among UTI causative agents in children are dominated by gram-negative bacteria, E. coli. According to modern clinical guidelines, the leading direction in the treatment of UTI in children is antibiotic therapy, which should be prescribed taking into account the sensitivity of microorganisms. Drugs of choice for UTI in children: cephalosporins or protected aminopenicillins


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