scholarly journals Antimicrobial susceptibility profiles of Staphylococcus spp. from domestic and wild animals

2016 ◽  
Vol 46 (12) ◽  
pp. 2148-2151 ◽  
Author(s):  
Isabela de Godoy ◽  
Danny Franciele da Silva Dias Moraes ◽  
Letícia Camara Pitchenin ◽  
Janaina Marcela Assunção Rosa ◽  
Francielle Cristina Kagueyama ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Rrna Gene ◽  
Wild Animals ◽  
Species Determination ◽  
Disk Diffusion Test ◽  
Susceptibility Profiles ◽  
Staphylococcus Spp ◽  
The 16S Rrna Gene

ABSTRACT: The aim of this study was to determine the prevalence and diversity of veterinary clinical isolates of Staphylococcus and analyze their antimicrobial susceptibility. One hundred Staphylococcus spp. clinical isolates from domestic and wild animals were subjected to partial sequencing of the 16S rRNA gene to species determination. Antimicrobial susceptibility was obtained by a disk diffusion test against six antibiotics: amoxicillin (AMX), cephalexin (LEX), ciprofloxacin (CIP), erythromycin (ERY), gentamicin (GEN) and trimethoprim-sulfamethoxazole (SXT). The most common specie was S. pseudintermedius (61%, 61/100) and resistance to ERY (57%, 57/100), SXT (50%, 50/100) and AMX (46%, 46/100) was detected most frequently. In total, 40% (40/100) of Staphylococcus spp. exhibited a multidrug-resistant (MDR) phenotype. Results of this study emphasize that animals are reservoir of MDR Staphylococcus spp.

scholarly journals Antimicrobial susceptibility, serotype distribution, virulence profile and molecular typing of piliated clinical isolates of pneumococci from east coast, Peninsular Malaysia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nurul Diana Dzaraly ◽  
Mohd Nasir Mohd Desa ◽  
AbdulRahman Muthanna ◽  
Siti Norbaya Masri ◽  
Niazlin Mohd Taib ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Antimicrobial Susceptibility ◽  
East Coast ◽  
Tertiary Hospital ◽  
Multidrug Resistant ◽  
Peninsular Malaysia ◽  
Clinical Isolates ◽  
Serotype Distribution ◽  
Antimicrobial Susceptibility Test ◽  
Conjugate Vaccines

AbstractPilus has been recently associated with pneumococcal pathogenesis in humans. The information regarding piliated isolates in Malaysia is scarce, especially in the less developed states on the east coast of Peninsular Malaysia. Therefore, we studied the characteristics of pneumococci, including the piliated isolates, in relation to antimicrobial susceptibility, serotypes, and genotypes at a major tertiary hospital on the east coast of Peninsular Malaysia. A total of 100 clinical isolates collected between September 2017 and December 2019 were subjected to serotyping, antimicrobial susceptibility test, and detection of pneumococcal virulence and pilus genes. Multilocus sequence typing (MLST) and phylogenetic analysis were performed only for piliated strains. The most frequent serotypes were 14 (17%), 6A/B (16%), 23F (12%), 19A (11%), and 19F (11%). The majority of isolates were resistant to erythromycin (42%), tetracycline (37%), and trimethoprim-sulfamethoxazole (24%). Piliated isolates occurred in a proportion of 19%; 47.3% of them were multidrug-resistant (MDR) and a majority had serotype 19F. This study showed ST236 was the most predominant sequence type (ST) among piliated isolates, which was related to PMEN clone Taiwan19F-14 (CC271). In the phylogenetic analysis, the piliated isolates were grouped into three major clades supported with 100% bootstrap values. Most piliated isolates belonged to internationally disseminated clones of S. pneumoniae, but pneumococcal conjugate vaccines (PCVs) have the potential to control them.

scholarly journals Gram-Negative Taxa and Antimicrobial Susceptibility after Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Danielle Barrios Steed ◽  
Tiffany Wang ◽  
Divyanshu Raheja ◽  
Alex D. Waldman ◽  
Ahmed Babiker ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Susceptibility ◽  
Fecal Microbiota Transplantation ◽  
Antibiotic Prescription ◽  
Multidrug Resistant ◽  
Fecal Microbiota ◽  
Gram Negative ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Susceptibility Profiles

ABSTRACT Fecal microbiota transplantation (FMT) has promising applications in reducing multidrug-resistant organism (MDRO) colonization and antibiotic resistance (AR) gene abundance. However, data on clinical microbiology results after FMT are limited. We examined the changes in antimicrobial susceptibility profiles in patients with Gram-negative infections in the year before and the year after treatment with FMT for recurrent Clostridioides difficile infection (RCDI). We also examined whether a history of FMT changed health care provider behavior with respect to culture ordering and antibiotic prescription. Medical records for RCDI patients who underwent FMT at Emory University between July 2012 and March 2017 were reviewed retrospectively. FMT-treated patients with Gram-negative culture data in the 1-year period preceding and the 1-year period following FMT were included. Demographic and clinical data were abstracted, including CDI history, frequency of Gram-negative cultures, microbiological results, and antibiotic prescription in response to positive cultures in the period following FMT. Twelve patients were included in this case series. We pooled data from infections at all body sites and found a decrease in the number of total and Gram-negative cultures post-FMT. We compared susceptibility profiles across taxa given the potential for horizontal transmission of AR elements and observed increased susceptibility to nitrofurantoin, trimethoprim-sulfamethoxazole, and the aminoglycosides. FMT did not drastically influence health care provider ordering of bacterial cultures or antibiotic prescribing practices. We observed a reduction in Gram-negative cultures and a trend toward increased antimicrobial susceptibility. This study supports further investigation of FMT as a means of improving antimicrobial susceptibility. IMPORTANCE Fecal microbiota transplantation (FMT), which is highly efficacious in treating recurrent C. difficile infection (RCDI), has a promising application in decolonization of multidrug-resistant organisms, reduction of antibiotic resistance gene abundance, and restoration of healthy intestinal microbiota. However, data representing clinical microbiology results after FMT are limited. We sought to characterize the differences in culture positivity and antimicrobial susceptibility profiles in patients with Gram-negative infections in the year before and the year after FMT for RCDI. Drawing on prior studies that had demonstrated the success of FMT in eradicating extraintestinal infections and the occurrence of patient-level interspecies transfer of resistance elements, we employed an agnostic analytic approach of reviewing the data irrespective of body site or species. In a small RCDI population, we observed an improvement in the antimicrobial susceptibility profile of Gram-negative bacteria following FMT, which supports further study of FMT as a strategy to combat antibiotic resistance.

Antimicrobial susceptibility and mechanisms of high-level macrolide resistance in clinical isolates of Moraxella nonliquefaciens

2014 ◽  
Vol 63 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Shotaro Nonaka ◽  
Kosuke Matsuzaki ◽  
Tomoya Kazama ◽  
Hiroyuki Nishiyama ◽  
Yoko Ida ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Ribosomal Proteins ◽  
Macrolide Resistance ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
Efflux System ◽  
Strong Activity ◽  
23S Rrna Gene ◽  
High Level

We investigated antimicrobial susceptibility and the molecular mechanism involved in conferring high-level macrolide resistance in 47 clinical isolates of Moraxella nonliquefaciens from Japan. Antimicrobial susceptibility was determined using Etest and agar dilution methods. Thirty-two erythromycin-non-susceptible strains were evaluated for the possibility of clonal spreading, using PFGE. To analyse the mechanism related to macrolide resistance, mutations in the 23S rRNA gene and the ribosomal proteins, and the presence of methylase genes were investigated by PCR and sequencing. The efflux system was examined using appropriate inhibitors. Penicillin, ampicillin, amoxicillin, cefixime, levofloxacin and antimicrobials containing β-lactamase inhibitors showed strong activity against 47 M. nonliquefaciens isolates. Thirty-two (68.1 %) of the 47 isolates showed high-level MICs to macrolides (MIC ≥128 mg l−1) and shared the A2058T mutation in the 23S rRNA gene. The geometric mean MIC to macrolides of A2058T-mutated strains was significantly higher than that of WT strains (P<0.0001). Thirty-two isolates with high-level macrolide MICs clustered into 30 patterns on the basis of the PFGE dendrogram, indicating that the macrolide-resistant strains were not clonal. In contrast, no common mutations of the ribosomal proteins or methylase genes, or overproduction of the efflux system were observed in A2058T-mutated strains. Moreover, of the 47 M. nonliquefaciens strains, 43 (91.5 %) were bro-1 and 4 (8.5 %) were bro-2 positive. Our results suggest that most M. nonliquefaciens clinical isolates show high-level macrolide resistance conferred by the A2058T mutation in the 23S rRNA gene. This study represents the first characterization of M. nonliquefaciens.

scholarly journals Antimicrobial Susceptibility and Characterization of Resistance Mechanisms of Corynebacterium urealyticum Clinical Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 404
Author(s):  
Itziar Chapartegui-González ◽  
Marta Fernández-Martínez ◽  
Ana Rodríguez-Fernández ◽  
Danilo J. P. Rocha ◽  
Eric R. G. R. Aguiar ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Point Mutations ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Tract Infections ◽  
Corynebacterium Urealyticum

Corynebacterium urealyticum is a non-diphtherial urease-producing clinically relevant corynebacterial, most frequently involved in urinary tract infections. Most of the C. urealyticum clinical isolates are frequently resistant to several antibiotics. We investigated the susceptibility of 40 C. urealyticum isolated in our institution during the period 2005–2017 to eight compounds representative of the main clinically relevant classes of antimicrobial agents. Antimicrobial susceptibility was determined by the Epsilometer test. Resistance genes were searched by PCR. All strains were susceptible to vancomycin whereas linezolid and rifampicin also showed good activity (MICs90 = 1 and 0.4 mg/L, respectively). Almost all isolates (39/40, 97.5%) were multidrug resistant. The highest resistance rate was observed for ampicillin (100%), followed by erythromycin (95%) and levofloxacin (95%). Ampicillin resistance was associated with the presence of the blaA gene, encoding a class A β-lactamase. The two rifampicin-resistant strains showed point mutations driving amino acid replacements in conserved residues of RNA polymerase subunit β (RpoB). Tetracycline resistance was due to an efflux-mediated mechanism. Thirty-nine PFGE patterns were identified among the 40 C. urealyticum, indicating that they were not clonally related, but producing sporadic infections. These findings raise the need of maintaining surveillance strategies among this multidrug resistant pathogen.

scholarly journals Molecular Analysis of Cross-Resistance to Capreomycin, Kanamycin, Amikacin, and Viomycin in Mycobacterium tuberculosis

2005 ◽  
Vol 49 (8) ◽  
pp. 3192-3197 ◽  
Author(s):  
Courtney E. Maus ◽  
Bonnie B. Plikaytis ◽  
Thomas M. Shinnick
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Molecular Basis ◽  
Multidrug Resistant ◽  
Single Step ◽  
Clinical Isolates ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Rrna Gene ◽  
Gene Encoding ◽  
Treatment Regimens

ABSTRACT Capreomycin, kanamycin, amikacin, and viomycin are drugs that are used to treat multidrug-resistant tuberculosis. Each inhibits translation, and cross-resistance to them is a concern during therapy. A recent study revealed that mutation of the tlyA gene, encoding a putative rRNA methyltransferase, confers capreomycin and viomycin resistance in Mycobacterium tuberculosis bacteria. Mutations in the 16S rRNA gene (rrs) have been associated with resistance to each of the drugs; however, reports of cross-resistance to the drugs have been variable. We investigated the role of rrs mutations in capreomycin resistance and examined the molecular basis of cross-resistance to the four drugs in M. tuberculosis laboratory-generated mutants and clinical isolates. Spontaneous mutants were generated to the drugs singularly and in combination by plating on medium containing one or two drugs. The frequencies of recovery of the mutants on single- and dual-drug plates were consistent with single-step mutations. The rrs genes of all mutants were sequenced, and the tlyA genes were sequenced for mutants selected on capreomycin, viomycin, or both; MICs of all four drugs were determined. Three rrs mutations (A1401G, C1402T, and G1484T) were found, and each was associated with a particular cross-resistance pattern. Similar mutations and cross-resistance patterns were found in drug-resistant clinical isolates. Overall, the data implicate rrs mutations as a molecular basis for resistance to each of the four drugs. Furthermore, the genotypic and phenotypic differences seen in the development of cross-resistance when M. tuberculosis bacteria were exposed to one or two drugs have implications for selection of treatment regimens.

scholarly journals Ex VivoActivity of Histone Deacetylase Inhibitors against Multidrug-Resistant Clinical Isolates ofPlasmodium falciparumandP. vivax

2010 ◽  
Vol 55 (3) ◽  
pp. 961-966 ◽  
Author(s):  
Jutta Marfurt ◽  
Ferryanto Chalfein ◽  
Pak Prayoga ◽  
Frans Wabiser ◽  
Enny Kenangalem ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitors ◽  
Ex Vivo ◽  
Hdac Inhibitors ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Antimalarial Therapy ◽  
Susceptibility Profiles ◽  
Antimalarial Compounds

ABSTRACTHistone acetylation plays an important role in regulating gene transcription and silencing inPlasmodium falciparum. Histone deacetylase (HDAC) inhibitors, particularly those of the hydroxamate class, have been shown to have potentin vitroactivity against drug-resistant and -sensitive laboratory strains ofP. falciparum, raising their potential as a new class of antimalarial compounds. In the current study, stage-specificex vivosusceptibility profiles of representative hydroxamate-based HDAC inhibitors suberoylanilide hydroxamic acid (SAHA), 2-ASA-9, and 2-ASA-14 (2-ASA-9 and 2-ASA-14 are 2-aminosuberic acid-based HDAC inhibitors) were assessed in multidrug-resistant clinical isolates ofP. falciparum(n= 24) andP. vivax(n= 25) from Papua, Indonesia, using a modified schizont maturation assay. Submicromolar concentrations of SAHA, 2-ASA-9, and 2-ASA-14 inhibited the growth of bothP. falciparum(median 50% inhibitory concentrations [IC50s] of 310, 533, and 266 nM) andP. vivax(median IC50s of 170, 503, and 278 nM). Inverse correlation patterns between HDAC inhibitors and chloroquine forP. falciparumand mefloquine forP. vivaxindicate species-specific susceptibility profiles for HDAC inhibitors. These HDAC inhibitors were also found to be potentex vivoagainstP.vivaxschizont maturation, comparable to that inP. falciparum, suggesting that HDAC inhibitors may be promising candidates for antimalarial therapy in geographical locations where both species are endemic. Further studies optimizing the selectivity andin vivoefficacy of HDAC inhibitors inPlasmodiumspp. and defining drug interaction with common antimalarial compounds are warranted to investigate the role of HDAC inhibitors in antimalarial therapy.

scholarly journals Mutations in the 16S rRNA Genes of Helicobacter pylori Mediate Resistance to Tetracycline

2002 ◽  
Vol 184 (8) ◽  
pp. 2131-2140 ◽  
Author(s):  
Catharine A. Trieber ◽  
Diane E. Taylor
Keyword(s):  
Helicobacter Pylori ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Tetracycline Resistance ◽  
Clinical Isolates ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Nucleotide Substitutions ◽  
The 16S Rrna Gene

ABSTRACT Low-cost and rescue treatments for Helicobacter pylori infections involve combinations of several drugs including tetracycline. Resistance to tetracycline has recently emerged in H. pylori. The 16S rRNA gene sequences of two tetracycline-resistant clinical isolates (MIC = 64 μg/ml) were determined and compared to the consensus H. pylori 16S rRNA sequence. One isolate had four nucleotide substitutions, and the other had four substitutions and two deletions. Natural transformation with the 16S rRNA genes from the resistant organisms conferred tetracycline resistance on susceptible strains. 16S rRNA genes containing the individual mutations were constructed and tested for the ability to confer resistance. Only the 16S rRNA gene containing the triple mutation, AGA965-967TTC, was able to confer tetracycline resistance on H. pylori 26695. The MICs of tetracycline for the transformed strains were equivalent to those for the original clinical isolates. The two original isolates were also metronidazole resistant, but this trait was not linked to the tetracycline resistance phenotype. Serial passage of several H. pylori strains on increasing concentrations of tetracycline yielded mutants with only a very modest increase in tetracycline resistance to a MIC of 4 to 8 μg/ml. These mutants all had a deletion of G942 in the 16S rRNA genes. The mutations in the 16S rRNA are clearly responsible for tetracycline resistance in H. pylori.

scholarly journals Bacteriological assessment of tap water collected from different markets of Mymensingh, Gazipur and Sherpur districts of Bangladesh with special focus on the molecular detection and antimicrobial resistance of the isolated Escherichia coli

2018 ◽  
Vol 2 (1) ◽  
pp. 21-28
Author(s):  
Md Shihab Hassan ◽  
SM Lutful Kabir ◽  
Yousuf Ali Sarker ◽  
Md Tanvir Rahman
Keyword(s):  
Antimicrobial Susceptibility ◽  
Water Samples ◽  
Tap Water ◽  
Geometric Mean ◽  
Multidrug Resistant ◽  
Total Coliform ◽  
Plate Count ◽  
Special Focus ◽  
Rrna Gene ◽  
E Coli

The objectives of this study were to assess the bacteriological quality of tap water samples obtained from different markets of different upazillas of Mymensingh, Sherpur & Gazipur district. For achieving the above mentioned objectives, methods of heterotrophic plate count (HPC) and total coliform count (TCC) were applied. Moreover, isolated E. coli from tap water samples were characterized by using biochemical test, molecular method and antimicrobial susceptibility tests. HPC was highest in market tap water collected from Kaligonj and TCC was highest in market tap water of collected from Mymensingh sadar. The geometric mean of HPC of Mymensingh, Gazipur and Sherpur districts water was 8.4x105, 2.5 x106 and 6.8 x105 C.F.U/100 ml. All isolates of E. coli (n=20) were amplified by using 16S rRNA gene based PCR. In respect to antimicrobial susceptibility testing, most of the E. coli isolates were susceptible to norfloxacin, ampicilin, tetracycline, streptomycin and ciprofloxacin. Furthermore, a few E. coli isolates were intermediate resistant to gentamycin and ciprofloxacin. However, a few of the E. coli isolates were resistant to erythromycin and amoxycilin. Moreover, out of 20 E. coli isolates 3 (15%) isolates were detected as multidrug resistant. This study indicated the presence of multidrug resistant E. coli isolates in tap water in Mymensingh, Sherpur and Gazipur districts that warrants particular attention. Asian Australas. J. Food Saf. Secur. 2018, 2(1), 21-28

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