Antibacterial Properties of Stainless Steel Coated on Ti6Al4V Alloy

open access journalTitanium alloys and stainless steeltype 316Lare used in biomedical applications due to their high corrosion resistance and good biocompatibility properties. In this study, a functionally graded material composed of titanium and stainless steel was fabricated usinga powder metallurgical technique. Ti6Al4V alloy powder was placed as a substrate into a graphite crucible and stainless steel powder was added as a thin layer on the Ti6Al4V powder. The two layers were consolidated in-situ using a uniaxial hot press. The sintering process was carried out at 1050 oC for 30 minutes under 50 MPa. The pressure was maintained during the whole sintering process. A disc shape compact of 20 mmdiameter and 5 mmthickness was obtained aftersintering. The samples were metallographically prepared and their antibacterial properties were evaluated. A strong bonding was observed between the Ti6Al4V substrate and the 316L stainless steel layer, and no bacteria were observed on the stainless steel surface

Comparison in a rat thigh abscess model of imipenem, meropenem and cefoperazone-sulbactam against Acinetobacter baumannii strains in terms of bactericidal efficacy and resistance selection

BACKGROUND: We compared imipenem, meropenem and cefoperazone-sulbactam against hospital originated A. baumannii strains in terms of bactericidal efficacy and selection of resistant mutants during treatment in a rat thigh abscess model. METHODS: A total of 18 strains were inoculated in 54 animals (one strain for three animals). Randomly selected 10 among these 18 strains were inoculated in another 10 rats as the control group. Imipenem, meropenem and cefoperazone-sulbactam were the antibiotics compared. After four days of treatment, Wistar albino rats (200 to 250 g) were sacrificed and the abscess materials were processed for mean colony counts and for the presence of resistant mutants. RESULTS: The mean CFUs per gram (mean ± (std. deviation) [×10(4)]) of the abscess were: 9,14 (25,24), 2,11 (3,78), 1,20 (1,70) in the imipenem (n = 17), meropenem (n = 18) and cefoperazone-sulbactam (n = 17) groups, respectively. The differences were not significant. On the other hand, no resistant mutant was detected in abscess materials. CONCLUSION: This study indicated; first, cefoperazone-sulbactam is comparable to carbapenems in bactericidal efficacy in this particular abscess model and second, emergence of resistance due to spontaneous mutations is not at least a frequent phenomenon among A. baumannii

Molecular characterization of carbapenemase producing Klebsiella pneumoniae strains by multiplex PCR and PFGE methods: The first K.pneumoniae isolates co-producing OXA-48/KPC and KPC/NDM in Turkey

© 2021 Japanese Society of Chemotherapy and The Japanese Association for Infectious DiseasesIntroduction: Carbapenems are frequently used in the treatment of multidrug-resistant infections caused by Klebsiella pneumoniae. The aim of the study is to definition and incidence of transferable carbapenemase genes of carbapenem resistant K. pneumoniae (CRKP) and to determine clonal relatedness of these strains in tertiary care hospital in Turkey. Methods: Identification of all 100 K. pneumoniae isolates and low sensitivity to any of the carbapenem group antibiotics were determined by Vitek-2 (BioMérieux, France). The frequency of carbapenemase genes (blaOXA-48, blaNDM, blaKPC, blaVIM, blaIMP) and extended spectrum beta-lactamase (ESBL) genes (blaCTX-M, blaSHV, blaTEM) which frequently detected in Turkey, have been investigated by multiplex polymerase chain reaction (PCR). Clonal relatedness was determined using Pulsed-field gel electrophoresis(PFGE). Results: Ninety five isolates carried at least one of the carbapenemase genes (81.05% blaOXA-48, 38.9% blaNDM, 9.47% blaKPC,1.05% blaVIM). One isolate was carried the blaOXA-48+KPC and the two isolates were carried the blaKPC+NDM. PFGE demonstrated the presence of 24 pulse types and 63.09% of the isolates were in four main pulse types. Conclusions: This study demonstrated the incidence of blaNDM is beginning to reach endemic levels, in addition to blaOXA-48 found endemic in Turkey. To our knowledge, this is the first report of the co-production of these two genes (blaKPC + NDM and blaOXA-48 + KPC) in CRKP isolates

In vitro antibacterial activity of various adhesive materials against oral streptococci

The purpose of this study was to investigate the antibacterial activity of various adhesive materials against five different oral streptococci. The antibacterial activity of the adhesive systems was evaluated using agar diffusion tests. In each section of each plate, 6-mm-diameter wells were created with sterilized glass cylinders. Ten microlitres of self-etch adhesives and control materials were applied into the shallow holes. After incubation at 37 °C for 24 h, the growth inhibition zones were measured in millimetres. Statistical analyses were performed by using two-way analysis of variance and the Tukey's multiple range test (p < 0.05). A statistically significant difference was found between inhibition zones of oral streptococci cultivated with different adhesive systems (p < 0.01). Clearfil Protect Bond exhibited larger inhibition zones than the other materials that were used against the oral streptococci. The antibacterial effects observed for the different tested adhesive systems may be related to 12-methacryloyloxy dodecyl-pyridinium bromide and the acidic nature of the materials

Characterization of ESBL (SHV-12) producing clinical isolate of <it>Enterobacter aerogenes </it>from a tertiary care hospital in Nigeria

Abstract Background We studied the beta-lactamases of an E. aerogenes isolate recovered from the blood of a two-year-old patient. The isolate demonstrated a disk-diffusion phenotype typical for an AmpC-ESBL co-producer. Methods Microbiology studies were performed according to standard protocols. The resistance gene was identified by transconjugation and cloning experiments. Results By transconjugation only a narrow spectrum beta-lactamase (TEM-1) encoded on a small plasmid was transmitted. The ESBL was cloned and expressed in an E. coli host. Sequence analysis of the recombinant plasmid revealed blaSHV-12 associated to the insertion sequence, IS26. Conclusion This is the first study demonstrated the occurrence of SHV-12 in Nigeria.</p

Genetic and Enzymatic Properties of Metallo-β-Lactamase VIM-5 from a Clinical Isolate of Enterobacter cloacae

A VIM-5-producing Enterobacter cloacae isolate (EDV/1) was identified in a collection of clinical strains stored before 2002. The gene, bla(VIM-5), was located on a 2,712-bp BamHI-HindIII fragment of a 23-kbp (approximately) nonconjugative plasmid (pEDV5) in a class 1 integron as a single gene cassette