scholarly journals Inducible Macrolide Resistance inCorynebacterium jeikeium

2001 ◽  
Vol 45 (7) ◽  
pp. 1982-1989 ◽  
Author(s):  
Adriana E. Rosato ◽  
Bonnie S. Lee ◽  
Kevin A. Nash
Keyword(s):  
Drug Resistance ◽  
Resistance Genes ◽  
Broad Spectrum ◽  
Antimicrobial Agents ◽  
Opportunistic Pathogen ◽  
Macrolide Resistance ◽  
The Other ◽  
Broad Spectrum Resistance ◽  
Neutropenic Patients ◽  
Group 3

ABSTRACT Corynebacterium jeikeium is an opportunistic pathogen primarily of immunocompromised (neutropenic) patients. Broad-spectrum resistance to antimicrobial agents is a common feature of C. jeikeium clinical isolates. We studied the profiles of susceptibility of 20 clinical strains of C. jeikeium to a range of antimicrobial agents. The strains were separated into two groups depending on the susceptibility to erythromycin (ERY), with one group (17 strains) representing resistant organisms (MIC > 128 μg/ml) and the second group (3 strains) representing susceptible organisms (MIC ≤ 0.25 μg/ml). The ERY resistance crossed to other members of the macrolide-lincosamide-streptogramin B (MLSb) group. Furthermore, this resistance was inducible with MLSb agents but not non-MLSb agents. Expression of ERY resistance was linked to the presence of an allele of the class X erm genes,erm(X)cj, with >93% identity to other ermgenes of this class. Our evidence indicates that erm(X)cj is integrated within the chromosome, which contrasts with previous reports for the plasmid-associated erm(X) genes found inC. diphtheriae and C. xerosis. In 40% ofC. jeikeium strains, erm(X)cj is present within the transposon, Tn5432. However, in the remaining strains, the components of Tn5432 (i.e., the erm and transposase genes) have separated within the chromosome. The rearrangement of Tn5432 leads to the possibility that the other drug resistance genes have become included in a new composite transposon bound by the IS1249 elements.

scholarly journals Dissection of broad-spectrum resistance of the Thai rice variety Jao Hom Nin conferred by two resistance genes against rice blast

Rice ◽  
2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Chaivarakun Chaipanya ◽  
Mary Jeanie Telebanco-Yanoria ◽  
Berlaine Quime ◽  
Apinya Longya ◽  
Siripar Korinsak ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Broad Spectrum ◽  
Rice Blast ◽  
Rice Variety ◽  
Broad Spectrum Resistance

scholarly journals High Temperature Enhances the Resistance of Cultivated African Rice, Oryza glaberrima, to Bacterial Blight

Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 380-387 ◽  
Author(s):  
Gerbert Sylvestre Dossa ◽  
Ricardo Oliva ◽  
Edgar Maiss ◽  
Casiana Vera Cruz ◽  
Kerstin Wydra
Keyword(s):  
High Temperature ◽  
Resistance Genes ◽  
Broad Spectrum ◽  
Host Resistance ◽  
Bacterial Blight ◽  
The Philippines ◽  
Oryza Glaberrima ◽  
Pathogen Invasion ◽  
Broad Spectrum Resistance ◽  
Wide Range

Rice bacterial blight (BB) is caused by Xanthomonas oryzae pv. oryzae and is responsible for substantial yield loss worldwide. Host resistance remains the most feasible control measure. However, pathogen variability leads to the failure of certain resistance genes to control the disease, and climate change with high amplitudes of heat predisposes the host plant to pathogen invasion. Due to pressure in natural selection, landrace species often carry a wide range of unique traits conferring tolerance of stress. Therefore, exploring their genetic background for host resistance could enable the identification of broad-spectrum resistance to combined abiotic and biotic stresses. Nineteen Oryza glaberrima accessions and O. sativa rice variety SUPA were evaluated for BB resistance under high temperature (35 and 31°C day and night, respectively) using 14 X. oryzae pv. oryzae strains originated from the Philippines. Under normal temperature, most of the accessions showed resistance to 9 strains (64.3%) and accession TOG6007 showed broad-spectrum resistance to 12 strains (85.7%). Under high temperature, most accessions showed a reduction in BB disease, whereas, accession TOG5620 showed disease reduction from all the X. oryzae pv. oryzae strains under high temperature. Molecular characterization using gene-based and linked markers for BB resistance genes Xa4, xa5, Xa7, xa13, and Xa21 revealed the susceptible alleles of Xa4, xa5, xa13, and Xa21 in O. glaberrima. However, no allele of Xa7 was detected among O. glaberrima accessions. Our results suggest that O. glaberrima accessions contain a BB resistance different from the Xa gene type. Genome-wide association mapping could be used to identify quantitative trait loci that are associated with BB resistance or combined BB resistance and high-temperature tolerance.

scholarly journals Molecular epidemiology and antimicrobial resistance features of Acinetobacter baumannii clinical isolates from Pakistan

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Nabil Karah ◽  
Fizza Khalid ◽  
Sun Nyunt Wai ◽  
Bernt Eric Uhlin ◽  
Irfan Ahmad
Keyword(s):  
Antimicrobial Resistance ◽  
Molecular Epidemiology ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Antimicrobial Agents ◽  
Opportunistic Pathogen ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Agar Disc ◽  
Antimicrobial Resistance Genes

Abstract Background Acinetobacter baumannii is a Gram-negative opportunistic pathogen with a notorious reputation of being resistant to antimicrobial agents. The capability of A. baumannii to persist and disseminate between healthcare settings has raised a major concern worldwide. Methods Our study investigated the antibiotic resistance features and molecular epidemiology of 52 clinical isolates of A. baumannii collected in Pakistan between 2013 and 2015. Antimicrobial susceptibility patterns were determined by the agar disc diffusion method. Comparative sequence analyses of the ampC and blaOXA-51-like alleles were used to assign the isolates into clusters. The whole genomes of 25 representative isolates were sequenced using the MiSeq Desktop Sequencer. Free online applications were used to determine the phylogeny of genomic sequences, retrieve the multilocus sequence types (ST), and detect acquired antimicrobial resistance genes. Results Overall, the isolates were grouped into 7 clusters and 3 sporadic isolates. The largest cluster, Ab-Pak-cluster-1 (blaOXA-66 and ISAba1-ampC-19) included 24 isolates, belonged to ST2 and International clone (IC) II, and was distributed between two geographical far-off cities, Lahore and Peshawar. Ab-Pak-clusters-2 (blaOXA-66, ISAba1-ampC-2), and -3 (blaOXA-66, ISAba1-ampC-20) and the individual isolate Ab-Pak-Lah-01 (ISAba1-blaOXA-66, ISAba1-ampC-2) were also assigned to ST2 and IC II. On the other hand, Ab-Pak-clusters-4 (blaOXA-69, ampC-1), -5 (blaOXA-69, ISAba1-ampC-78), and -6A (blaOXA-371, ISAba1-ampC-3) belonged to ST1, while Ab-Pak-cluster-6B (blaOXA-371, ISAba1-ampC-8) belonged to ST1106, with both ST1 and ST1106 being members of IC I. Five isolates belonged to Ab-Pak-cluster-7 (blaOXA-65, ampC-43). This cluster corresponded to ST158, showed a well-delineated position on the genomic phylogenetic tree, and was equipped with several antimicrobial resistance genes including blaOXA-23 and blaGES-11. Conclusions Our study detected the occurrence of 7 clusters of A. baumannii in Pakistan. Altogether, 6/7 of the clusters and 45/52 (86.5%) of the isolates belonged to IC I (n = 9) or II (n = 36), making Pakistan no exception to the global domination of these two clones. The onset of ST158 in Pakistan marked a geographical dispersal of this clone beyond the Middle East and brought up the need for a detailed characterization.

Antifungal Treatment with Caspofungin: A Single Centre Experience.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5386-5386
Author(s):  
Alessandro Bonini ◽  
Alessia Tieghi ◽  
Luigi Gugliotta
Keyword(s):  
Adverse Events ◽  
Antibiotic Therapy ◽  
Fungal Infection ◽  
Broad Spectrum ◽  
Fungal Infections ◽  
The Other ◽  
Broad Spectrum Antibiotic ◽  
Persistent Fever ◽  
Neutropenic Patients ◽  
The Mean

Abstract Infections are the main complication for patients with hematologic diseases and severe neutropenia and among them fungal infections are the most diffucult to treat and a major cause of mortality for these patients. Now we have a new antifungal class, Echinocandins which work with a new and different mechanism of action regarding azoles and amphotericin B, so we wanted to verify the tolerability and efficacy of Caspofungin (Caspo). From January 2004 until now we have treated 15 consecutive oncohemopatic and neutropenic patients admitted at our Institution. The schedule of treatment was: in case of persistent fever (at least 4 days) during broad spectrum antibiotic therapy a high-resolution CT-scan of the lungs, an abdomen US-scan, swabs from pharynx, nose and rectum and blood cultures were performed. In case of positivity of one or more of these findings suggesting for invasive fungal disease, Caspofungin was administered at the dosage of 70 mg i.v. on the first day and 50 mg i.v. from the second day; the infusion time was 1 hour. The patients were 10 males and 5 females, the mean age was 46 yrs (range 19–60 yrs). The diagnoses were: acute myeloid leukemia 8, acute lymphoblastic leukemia 3, lymphoma 4; the disease’s phases were: onset 3, first remission 3, remission>I 2, partial remission 5, relapse 1, resistant 1. Two patients received an allogeneic BMT, 1 an autologous BMT, the other patients an induction or consolidation or rescue chemotherapy course. In four cases Caspo was administered as secondary prophylaxis of a previous invasive fungal infection while for the other patients Caspo was administered for persistent fever and at least one lesion of the lungs or other organs with no evidence of bacterial or viral infection. The mean time of treatment was 18 days (range 6–21 days); the treatment was not discontinued for anyone of them because of adverse events; the dosage of Caspo was not changed for anyone. For the 2 allogeneic BMT Cyclosporine A administration was not changed and we did not found any renal or liver alterations. All the patients received a concomitant broad spectrum antibiotic therapy (association of Tazobactam/Piperacilline, Amikacine and Vancomycin) and for none of them we registered any liver or renal disfunction. No adverse events during the infusion of Caspo were seen and it was not necessary to administer any drug before the infusion. We did not seen breakthrough fungal infections. In 2 patients a proven fungal infection (Aspergillus fumigatus and Aspergillus spp) was demonstrated so the other cases remained probable or possible infections. No progression of the infection was seen. All the infections, except one, resolved; one patient died after 6 days of antifungal treatment for leukemia progression. Five patients died: 4 for leukemia and 1 for bacterial infection (Pseudomonas aeruginosa) after the fungal infection. In conclusion now we have a new treatment option for fungal infections in neutropenic patients and this option is safe, it does not preclude any other treatment (such as CsA), it is well tolerated and the resolution rate of the infections is very high, probably because of the new mechanism of action of the drug. Moreover the cost of the drug is lower than other antifungal treatments. According to these preliminary data we have decided to continue this experience to verify them in a larger cohort of patients.

scholarly journals Genome of the Opportunistic Pathogen Streptococcus sanguinis

2007 ◽  
Vol 189 (8) ◽  
pp. 3166-3175 ◽  
Author(s):  
Ping Xu ◽  
Joao M. Alves ◽  
Todd Kitten ◽  
Arunsri Brown ◽  
Zhenming Chen ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Opportunistic Pathogen ◽  
Surface Proteins ◽  
The Other ◽  
Vitamin B ◽  
Circular Dna ◽  
Streptococcus Sanguinis ◽  
Dna Molecule ◽  
Neutropenic Patients

ABSTRACT The genome of Streptococcus sanguinis is a circular DNA molecule consisting of 2,388,435 bp and is 177 to 590 kb larger than the other 21 streptococcal genomes that have been sequenced. The G+C content of the S. sanguinis genome is 43.4%, which is considerably higher than the G+C contents of other streptococci. The genome encodes 2,274 predicted proteins, 61 tRNAs, and four rRNA operons. A 70-kb region encoding pathways for vitamin B12 biosynthesis and degradation of ethanolamine and propanediol was apparently acquired by horizontal gene transfer. The gene complement suggests new hypotheses for the pathogenesis and virulence of S. sanguinis and differs from the gene complements of other pathogenic and nonpathogenic streptococci. In particular, S. sanguinis possesses a remarkable abundance of putative surface proteins, which may permit it to be a primary colonizer of the oral cavity and agent of streptococcal endocarditis and infection in neutropenic patients.

scholarly journals Identification of resistant germplasm containing novel resistance genes at or tightly linked to the Pi2/9 locus conferring broad-spectrum resistance against rice blast

Rice ◽  
2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Gui Xiao ◽  
Frances Nikki Borja ◽  
Ramil Mauleon ◽  
Jonas Padilla ◽  
Mary Jeanie Telebanco-Yanoria ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Broad Spectrum ◽  
Rice Blast ◽  
Broad Spectrum Resistance

scholarly journals Prevalence of virulence and antimicrobial resistance genes in Salmonella spp. isolated from commercial chickens and human clinical isolates from South Africa and Brazil

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Oliver T. Zishiri ◽  
Nelisiwe Mkhize ◽  
Samson Mukaratirwa
Keyword(s):  
Drug Resistance ◽  
Antimicrobial Resistance ◽  
South African ◽  
Resistance Genes ◽  
Broiler Chickens ◽  
Antimicrobial Agents ◽  
Multiple Drug Resistance ◽  
Multiple Drug ◽  
Poultry Production ◽  
Antimicrobial Resistance Genes

Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to mitigate the proliferation of multiple drug resistance across species.Keywords: Salmonella; antimicrobial resistance; chicken; human; susceptibility; virulence gene

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