scholarly journals Microbial profile in infectious keratitis over 8 years in Sao Paulo, Brazil: pathogens and microbial resistance

Author(s):  
Luiza Manhezi Shin de Oliveira ◽  
Tatiana Tanaka ◽  
Juliana Mika Kato ◽  
Regina Sayuri Yamashiro Shiotuki ◽  
Karoline de Lemes Giuntini Corrêa ◽  
...  

Abstract Objective Infectious keratitis remains a sight-threatening disease and its prompt diagnosis and treatment are critical. This study investigated the microbiological patterns of isolates in corneal ulcers in a tertiary health center in an 8-year period. Methods Retrospective analysis of scrapes of microbial keratitis performed from January 2013 to December 2020. Demographics and microbiological data were collected. Results A total of 446 scrapes were performed on eyes of 433 patients, 270 male (62.4%), mean age 51.7 years. 304 organisms were isolated from 248 (55.6%) positive samples. Polymicrobial infections occurred in 47 samples (19.0%). Bacterial isolates represented 86.8%: 53.3% gram-positive (GP), 33.5% gram-negative (GN). Cutibacterium acnes (12.2%) and Pseudomonas aeruginosa (9.9%) were the most common bacteria. Fungal keratitis comprised 11.8% of the isolates; Fusarium sp (6.2%) was the main fungus isolated. GP tested were sensitive to vancomycin, 98.7% of the GN were sensitive to ceftazidime. All Pseudomonas aeruginosa were sensitive to gentamicin and ciprofloxacin. Conclusion Gram-positive bacteria were predominant in keratitis isolates. In severe bacterial keratitis in our area, vancomycin should be considered as empirical treatment.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jayaraman Kaliamurthy ◽  
Catti Muniswamy Kalavathy ◽  
Pragya Parmar ◽  
Christadas Arul Nelson Jesudasan ◽  
Philip A. Thomas

Aim. To report the aetiological spectrum and susceptibility patterns of bacteria isolated from patients with corneal ulceration.Method. The microbiological data of all patients with suspected infectious corneal ulceration who presented to the ocular microbiology service at this centre between 2005 and 2012 were reviewed retrospectively.Result. Microorganisms were recovered from 1665 (77%) of the 2170 ulcers. Bacterial isolates accounted for 1205 of the organisms isolated. The most common bacterial pathogens isolated were various species ofStaphylococcus, representing 777 (64.5%), followed byStaphylococcusspp. (148; 12.3%) andPseudomonas aeruginosa(117; 9.7%). High percentages of Gram-positive bacteria were susceptible to gatifloxacin (>94%), followed by ofloxacin and moxifloxacin. Almost 90% ofPseudomonas aeruginosaisolates were susceptible to ciprofloxacin and moxifloxacin. Sixty-two (44%) of 140 isolates ofStreptococcus pneumoniae, 79 (14.8%) of 534 isolates ofStaphylococcus epidermidis,and 33 (14%) of 234 isolates ofStaphylococcus aureuswere resistant to three or more antibiotics.Conclusion.Staphylococcusspp. were the most common bacterial pathogens isolated from patients with keratitis in this setting. High percentages of Gram-positive and Gram-negative bacteria were susceptible to gatifloxacin and moxifloxacin, respectively. Interestingly, a high percentage ofStreptococcus pneumoniaeisolates were found to be resistant to three or more antibiotics.


1995 ◽  
Vol 39 (4) ◽  
pp. 850-853 ◽  
Author(s):  
G M Eliopoulos ◽  
C B Wennersten ◽  
G Cole ◽  
D Chu ◽  
D Pizzuti ◽  
...  

This study evaluated the in vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent. The drug inhibited all tested members of the family Enterobacteriaceae at < or = 0.5 microgram/ml and all tested Pseudomonas aeruginosa, Burkholderia (Pseudomonas) cepacia, and Xanthomonas maltophilia strains at < or = 2 micrograms/ml. All but two strains of gram-positive bacteria were inhibited by < or = 1 microgram of the new drug per ml, including isolates highly resistant to ciprofloxacin.


Author(s):  
Sotianingsih Sotianingsih ◽  
Samsirun H. ◽  
Lipinwati Lipinwati

Pneumonia is defined as an inflammation of the lungs caused by microorganisms (bacteria, viruses, fungi, parasites). This research aimed to determine the pneumonia-causing bacteria along with the sensitivity and the antibiotic resistance test. This research was a descriptive study with samples of ICU pneumonia patients at Raden Mattaher Regional Hospital during the study period. All samples were consecutively selected. Samples for blood culture were incubated in the BactAlert device, whereas the sensitivity test was then performed using Vitex instruments. Sputum was previously enriched with BHI media and then cultured on culture media, and sensitivity test with the Vitex instruments was carried out. Of the 354 ICU patients during the study period, 30 patients (11.8%) had pneumonia, but only 19 patients could undergo sputum culture. Five of 19 patients were infected with Gram-positive bacteria, and 14 patients were infected with Gram-negative bacteria. The most commonly found bacteria were Klebsiella pneumonia (36.84%), followed by Acinetobacter baumanii (21.05%) and Pseudomonas aeruginosa (10.53%). Gram-negative bacteria obtained from sputum culture in this study were resistant to almost all antibiotic groups, especially penicillin, cephalosporin, quinolone, and tetracycline groups. Gram-positive bacteria obtained from sputum culture in this study were resistant to the penicillin antibiotic. The most commonly found bacteria were Klebsiella pneumonia (36.84%), followed by Acinetobacter baumanii (21.05%) and Pseudomonas aeruginosa (10.53%). The bacteria cultured from the sputum showed multidrug resistance mainly to the penicillin and cephalosporin antibiotic. This research data can be used to consider the treatment of pneumonia patients to decide more appropriate therapy.


2019 ◽  
Author(s):  
Theodoulakis Christofi ◽  
Stavria Panayidou ◽  
Irini Dieronitou ◽  
Christina Michael ◽  
Yiorgos Apidianakis

AbstractGut microbiota acts as a barrier against intestinal pathogens, but species-specific protection of the host from infection remains relatively unexplored. Taking a Koch’s postulates approach in reverse to define health-promoting microbes we find thatEscherichia colinaturally colonizes the gut of healthy mice, but it is depleted from the gut of antibiotic-treated mice, which become susceptible to intestinal colonization byPseudomonas aeruginosaand concomitant mortality. Reintroduction of fecal bacteria andE. coliestablishes a high titer ofE. coliin the host intestine and increases defence againstP. aeruginosacolonization and mortality. Moreover, diet is relevant in this process because high sugars or dietary fat favoursE. colifermentation to lactic acid andP. aeruginosagrowth inhibition. To the contrary, low sugars allowP. aeruginosato produce the oxidative agent pyocyanin that inhibitsE. coligrowth. Our results provide an explanation as to whyP. aeruginosadoesn’t commonly infect the human gut, despite being a formidable microbe in lung and wound infections.Author SummaryHere we interrogate the conundrum as to whyPseudomonas aeruginosais not a clinical problem in the intestine as opposed to other tissues.P. aeruginosainteracts with Neisseria, Streptococcus, Staphylococcus and Actinomyces species found in the human lung. These are predominantly gram-positive bacteria that induceP. aeruginosavirulence. Moreover, peptidoglycan, which is abundant in gram-positive bacteria, can directly trigger the virulence ofP. aeriginosa. We reasoned thatP. aeruginosamight be benign in the human gut due to the inhibitory action of benign gram-negative intestinal bacteria, such asEscherichia coli. Therefore, we dissected the antagonism betweenE. coliandP. aeruginosaand the effect of a conventional, a fat-, a carbohydrate-and a protein-based diet in intestinal dysbiosis. Our findings support the notion that an unbalanced diet or antibiotics induces gut dysbiosis by the elimination of commensalE. coli, in addition to lactic acid bacteria, imposing a gut environment conducive toP. aeruginosainfection. Moreover, commensalE. coliprovides an explanation as to whyP. aeruginosadoesn’t commonly infect the human gut, despite being a formidable microbe in lung and wound infections.


2020 ◽  
Vol 12 (2) ◽  
pp. 56-63
Author(s):  
Marko Naumovski ◽  
Ivamaria Jovanovska ◽  
Kakja Popovska ◽  
Vesna Velikj Stefanovska ◽  
Gordana Mirchevska

In recent years, snakes have become suitable pets for people with little spare time. By buying these animals people ignore the fact that they carry many microorganisms that are pathogenic for humans. The idea of ​​this study was to identify the microorganisms from the oral cavity of exotic snakes kept as pets in the Republic of North Macedonia, which can help in the treatment of bite infections if they occur. The study comprised 30 snakes of 9 species, from 3 families of non-venomous snakes: Pythonidae, Boidae and Colubridae. Snakes are part of the 5 largest collections of exotic snakes in the Republic of North Macedonia. Only one swab from the oral cavity was taken from each snake. The brushes were cultured and microscopically analyzed at the Institute of Microbiology and Parasitology at the Faculty of Medicine in Skopje. From 59 isolated microorganisms from the oral cavity of 30 exotic snakes, 37.3% were Gram-positive bacteria, 61.01% were Gram-negative bacteria and 1.69% were fungi. Of the total number of microorganisms, Pseudomonas aeruginosa was predominant with 27.11%, Providencia rettgeri / Proteus vulgaris with 18.64% and KONS / Micrococcus luteus with 16.94%. Pseudomonas aeruginosa was present in all three snake families, with 62.5% of the snake in the fam. Pythonidae; 50% in the fam. Boidae and 50% in the fam. Colubridae. The isolate Providencia rettgeri / Proteus vulgaris was most frequently found in the fam. Colubridae with 71.43%, followed by fam. Pythonidae with 12.5%, but was not isolated in any specimen of the fam. Boidae. The microbiome of the non-venomous snakes is composed of Gram-positive bacteria in healthy snakes, but also in snakes kept in inadequate hygienic conditions. Gram-negative bacteria were predominant, of which the most significant was the presence of multiple drug resistance Pseudomonas aeruginosa. Snakes as pets require proper knowledge of terms and conditions.


Marine Drugs ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 43 ◽  
Author(s):  
Ruilian Li ◽  
Xianghua Yuan ◽  
Jinhua Wei ◽  
Xiafei Zhang ◽  
Gong Cheng ◽  
...  

Microbial biofilms are considerably more resistant to antibiotics than planktonic cells. It has been reported that chitosan coupling with the aminoglycoside antibiotic streptomycin dramatically disrupted biofilms of several Gram-positive bacteria. This finding suggested the application of the covalent conjugate of antimicrobial natural polysaccharides and antibiotics on anti-infection therapy. However, the underlying molecular mechanism of the chitosan-streptomycin conjugate (CS-Strep) remains unclear and the poor water-solubility of the conjugate might restrict its applications for anti-infection therapy. In this study, we conjugated streptomycin with water-soluble chitosan oligosaccharides (COS). Unlike CS-Strep, the COS-streptomycin conjugate (COS-Strep) barely affected biofilms of tested Gram-positive bacteria. However, COS-Strep efficiently eradicated established biofilms of the Gram-negative pathogen Pseudomonas aeruginosa. This activity of COS-Strep was influenced by the degree of polymerization of chitosan oligosaccharide. The increased susceptibility of P. aeruginosa biofilms to antibiotics after conjugating might be related to the following: Suppression of the activation of MexX-MexY drug efflux pump system induced by streptomycin treatment; and down-regulation of the biosynthesis of biofilm exopolysaccharides. Thus, this work indicated that covalently linking antibiotics to chitosan oligosaccharides was a possible approach for the development of antimicrobial drugs against biofilm-related infections.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 641 ◽  
Author(s):  
Seemi Tasnim Alam ◽  
Tram Anh Ngoc Le ◽  
Jin-Soo Park ◽  
Hak Cheol Kwon ◽  
Kyungsu Kang

Bacterial antibiotic resistance is an alarming global issue that requires alternative antimicrobial methods to which there is no resistance. Antimicrobial photodynamic therapy (APDT) is a well-known method to combat this problem for many pathogens, especially Gram-positive bacteria and fungi. Hypericin and orange light APDT efficiently kill Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and the yeast Candida albicans. Although Gram-positive bacteria and many fungi are readily killed with APDT, Gram-negative bacteria are difficult to kill due to their different cell wall structures. Pseudomonas aeruginosa is one of the most important opportunistic, life-threatening Gram-negative pathogens. However, it cannot be killed successfully by hypericin and orange light APDT. P. aeruginosa is ampicillin resistant, but we hypothesized that ampicillin could still damage the cell wall, which can promote photosensitizer uptake into Gram-negative cells. Using hypericin and ampicillin cotreatment followed by orange light, a significant reduction (3.4 log) in P. aeruginosa PAO1 was achieved. P. aeruginosa PAO1 inactivation and gut permeability improvement by APDT were successfully shown in a Caenorhabditis elegans model.


2016 ◽  
Vol 71 (5-6) ◽  
pp. 133-140 ◽  
Author(s):  
Asma Mohamed Mahran ◽  
Nasser Abdelhamid Hassan ◽  
Dalia Ahmed A. Osman ◽  
Sherif Shaban Ragab ◽  
Allam Abdelhamid Hassan

Abstract Starting from 6-aryl-5-cyano-2-thiouracil derivative 1a–f, a series of novel thiazolo[3,2-a]pyrimidines 4a–f were synthesized. The mechanism and the regioselectivity of the studied reactions are discussed. In addition, a series of tetrahydro-4-H-pyrimido[2,1-b][1,3]thiazines 7a–e and 2-((ethoxymethyl)thio)-4-aryl-1,6-dihydropyrimidines 9b,c,e were synthesized. The anti-microbial activities of some of the prepared compounds were screened, and the results revealed that compounds 3c and 4c were more active than the standard (Ampicillin) against gram positive bacteria (Pseudomonas aeruginosa). Moreover, compounds 4b,e and 3f were found to be good antifungal agents against the studied fungal strains.


1999 ◽  
Vol 45 (9) ◽  
pp. 791-796 ◽  
Author(s):  
Andrew M Kropinski ◽  
Mary Jo Sibbald

Using tRNAscan-SE and FAStRNA we have identified four tRNA genes in the delayed early region of the bacteriophage D3 genome (GenBank accession No. AF077308). These are specific for methionine (AUG), glycine (GGA), asparagine (AAC), and threonine (ACA). The D3 Thr- and Gly-tRNAs recognize codons, which are rarely used in Pseudomonas aeruginosa and presumably, influence the rate of translation of phage proteins. BLASTN searches revealed that the D3 tRNA genes have homology to tRNA genes from Gram-positive bacteria. Analysis of codon usage in the 91 ORFs discovered in D3 indicates patterns of codon usage reminiscent of Escherichia coli or P. aeruginosa.Key words: bacteriophage, Pseudomonas, D3, tRNA, codon usage.


2021 ◽  
Vol 9 (2) ◽  
pp. 64-70
Author(s):  
Ahmed A. Al-Naqshbandi ◽  
Hedy A. Hassan ◽  
Mahmoud A. Chawsheen ◽  
Haval H. Abdul Qader

Wound infection with antibiotic-resistant bacteria can extend a patients’ debility and increase the expense of treatment in the long term; therefore, careful management of patients with wound infections is necessary to avoid complications. The usage of antimicrobial agent is a major factor in resistance development. This study aims to understand the causes of wound infections, as well as the criteria for diagnosing them for more sensible antibiotic prescribing. Samples from 269 wound patients were collected, and cultured for bacterial growth. Gram stain technique, bacterial identification via VITEK 2 compact system were investigated in this study. Gram negative bacteria accounted for 59.15% of the total isolates, while pathogenic gram positive bacteria accounted for 40.85% of total isolates. Escherichia coli and Pseudomonas aeruginosa are the dominant pathogenic gram negative bacteria in wounds, while Staphylococcus aureus, and Staphylococcus epidermidis are the dominant pathogenic gram positive bacteria. Pseudomonas aeruginosa showed 100% resistance to the majority of antibiotic tested, including Ampicillin, Amoxicillin/Clavulanic Acid, Aztreona, Ceftriaxone, and others. Staphylococcus aureus and Staphylococcus epidermidis are 100% resistant to Ampicillin, Ceftriaxone, and Cefotaxime. For more efficient antibiotic prescriptions, the causative microorganisms, and their current susceptibility patterns need to be mandated for testing before prescribing any antibiotics to patients. Prescriptions are frequently based solely on general information about the antibiotic's function, rather than on individual response variation to the pathogen and the antibiotic. Particularly when the common pathogens in this study show multidrug resistance in wounds.


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