Research Article Characterization and molecular epidemiology of extensively prevalent nosocomial isolates of drug-resistant &lt;i&gt;Klebsiella pneumoniae&lt;/i&gt;

Lima, Evilda Rodrigues de; Carvalho, Andreia; Xavier, Mauro Aparecido de Sousa; Curzio, H.S.N.; Guedes, H.R.; Fernandes, L.F.; Almeida, Anna Christina de; Menezes, E.V.; Barreto, Nair Amélia Prates; Cardoso, Luís Leónidas; Xavier, A.R.E.O.

doi:10.4238/gmr18172

Cited by 3 publications

(3 citation statements)

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“…The stability of the formation of K. pneumoniae biofilms changed on exposure to 3-methyl-2 (5H)-furanone and 2′-hydroxycinnamic acid, inhibiting optical density by 67.38% and 65.06%, respectively. The formed biofilms were more susceptible to gentamicin [22][23][24].…”

Section: Resultsmentioning

confidence: 99%

Morphological and adhesive properties of Klebsiella pneumoniae biofilms

et al. 2020

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Background and Aim: The study of biofilm-forming ability of Gram-negative microflora has great practical importance for assessing the effectiveness of antibiotic therapy and finding new ways to diagnose and inhibit the growth of biofilms. This is because poor penetration of antibacterial drugs into the biofilm can lead to the selection of resistant strains and has a consequence evident by the occurrence of relapse of infection in animals. This study aimed to evaluate morphological and densitometric indicators of biofilm formation as well as adhesive properties of Klebsiella pneumoniae. Materials and Methods: K. pneumoniae was cultured at 37°C for 2-144 h in vitro. The specimens for optical microscopy were prepared by fixation with a 1:1 alcohol-ether mixture for 10 min and stained with a 0.5% solution of gentian violet for 2 min, and the optical density index was evaluated at a wavelength of 490 nm. Further, the adhesive properties of the microorganisms were determined at a concentration of 1 billion/ml and a suspension of ram erythrocytes at a concentration of 100 million/ml when cultured at 37°C for 24 h. Blood smears were prepared and stained with 0.5% gentian violet. Results: K. pneumonia cultured at 37°C after 24 h on the meat peptone agar formed large, convex, mucous, and white colonies (d=3.0-6.0 mm). With the growth in the meat and peptone broth, uniform turbidity of the medium was observed. Analyzing the optical density indices (density, D), it was found that K. pneumoniae were good producers of biofilms (D=0.528±0.31). Data for indicators of adhesive properties of K. pneumoniae were as follows: Average adhesion index, 4.56±0.14; adhesion coefficient, 1.07±0.52; and adhesion index, 4.26±0.07. The studied bacteria had high adhesive activity. A direct correlation dependence (R=0.94) of the optical density of biofilms (D≥0.514-0.551) and AAI (4.15±0.28-4.76±0.75) was established. Conclusion: This study has demonstrated that K. pneumoniae had high adhesive activity, was strong producer of biofilms, and the optical density of the sample exceeded the optical density of the control by more than 4 times.

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Section: Resultsmentioning

confidence: 99%

Morphological and adhesive properties of Klebsiella pneumoniae biofilms

et al. 2020

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“…The presence of genes that encode the expression of carbapenem-type beta-lactamases has been described in Acinetobacter spp. [19,20] and Klebsiella pneumoniae [21,22]. These organisms are also potential etiologic agents of bovine mastitis [23][24][25][26], as well as disseminators of resistance genes to other pathogens [27].…”

Section: Introductionmentioning

confidence: 99%

“…These organisms are also potential etiologic agents of bovine mastitis [23][24][25][26], as well as disseminators of resistance genes to other pathogens [27]. In Acinetobacter baumannii, resistance to carbapenem agents can be attributed to the presence of the gene bla Oxa23 [19,20] and to the gene bla KPC in K. pneumoniae [21,22]. The presence of the gene bla Oxa23 has already been reported in pathogens other than A. baumannii, confirming the transferability of this gene to other species of microorganisms [28,29].…”

Section: Introductionmentioning

confidence: 99%

Characterization and molecular epidemiology of Staphylococcus aureus strains resistant to beta-lactams isolated from the milk of cows diagnosed with subclinical mastitis

et al. 2019

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Background and Aim: The term ESKAPE, recognized by the WHO, is an acronym, which refers to the pathogens Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp., which is extremely virulent and multidrug-resistant. Although the term is used to designate nosocomial pathogens, in a milking environment, strains of Methicillin-resistant S. aureus have been isolated from cattle diagnosed with clinical and subclinical mastitis. Resistant strains may be involved in the transfer of genes conferring resistance to beta-lactam antimicrobials among the species of microorganisms related to mastitis etiology. This study aimed to trace the phenotypic and genotypic profiles of susceptibility to beta-lactams in S. aureus isolated from milk of cattle diagnosed with subclinical mastitis obtained from different rural properties located in the North of Minas Gerais State, Brazil. Materials and Methods: Sixteen microorganisms previously identified as S. aureus isolated from milk of cattle diagnosed with subclinical mastitis were submitted to matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF), mass spectrometry, and polymerase chain reaction (PCR) analysis for microbial species confirmation. The S. aureus beta-lactams antimicrobial phenotypic resistance profile was investigated by disk diffusion method. PCR methods were also performed to investigate the S. aureus genotypic beta-lactams resistance profile. For this purpose, blaZ, mecA, mecALGA251, blaOxa23, and blaKPC genes were screened among S. aureus isolates. The genetic diversity of S. aureus by fingerprint random amplified polymorphic DNA (RAPD)-PCR was also performed in this study. Results: All isolates showed phenotypic resistance to at least three beta-lactams, among which was meropenem. None of the isolates tested positive for the genes mecALGA251, blaOxa23, and blaKPC; however, the presence of the genes blaZ and mecA was detected among the isolates. The fingerprint analysis divided isolates into two distinct groups and 15 different subgroups. Despite the presence of clonality among the isolates, the PCR-RAPD analysis unveiled a heterogeneous profile with genetic diversity among the S. aureus isolates. Conclusion: In this study, we identified beta-lactams resistant S. aureus strains isolated from the milk of cows diagnosed with subclinical mastitis. The S. aureus beta-lactams resistance was investigated using a phenotypic and genotypic approach. We believe that molecular epidemiology, improved knowledge, and genetic basis of resistance to beta-lactams might assist in asserting guidelines for better management practices of dealing with subclinical mastitis and mapping of origin of resistant pathogens in the studied Brazilian area.

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