scholarly journals Characterization of Streptomycin Resistance in Isolates of Erwinia amylovora in California

2015 ◽  
Vol 105 (10) ◽  
pp. 1302-1310 ◽  
Author(s):  
Helga Förster ◽  
Gayle C. McGhee ◽  
George W. Sundin ◽  
James E. Adaskaveg
Keyword(s):  
Erwinia Amylovora ◽  
Streptomycin Resistance ◽  
Sacramento County ◽  
High Incidence ◽  
Short Palindromic Repeat ◽  
Efficient Expression ◽  
Resistant Strains ◽  
Low Incidence ◽  
Moderately Resistant

In surveys from 2006 to 2014, streptomycin resistance in Erwinia amylovora from pear-growing areas in California declined from very high incidence in 2006 and 2007 to very low incidence in 2013 and 2014. The majority of resistant strains were designated as moderately resistant-low (MR-L), and were almost exclusively found in Sacramento County, whereas highly resistant (HR) strains were only recovered in Sutter-Yuba and San Joaquin counties. Resistance of HR strains was associated with a mutation in codon 43 of the chromosomal rpsL gene that results in a change from lysine to arginine, the same mutation that was originally reported for resistant strains from California in the mid-1970s. MR-L strains were found to harbor the strA-strB streptomycin resistance genes on transposon Tn5393a. This transposon lacks insertion sequence IS1133 that provides a promoter for efficient expression of strA-strB, resulting in lower minimum inhibitory concentrations of MR-L strains compared with those from other locations that harbor strA-strB on Tn5393::IS1133. In contrast to previously described plasmid-mediated resistance where Tn5393 is inserted in pEa34, or pEA29, Tn5393a in MR-L strains was located on plasmid pEU30. This plasmid was first described in E. amylovora from the western United States but was not associated with streptomycin resistance determinants previously. We hypothesize that Tn5393a was introduced into an E. amylovora strain carrying pEU30 and transposed into that plasmid. This hypothesis was supported by clustered regularly interspaced short palindromic repeat (CRISPR) sequence analysis that showed that two MR-L strains share the same CRISPR1 pattern as a streptomycin-sensitive strain. With current low resistance levels in California growing regions, streptomycin could be successfully used again, but applications per season should be limited and the antibiotic should be mixed and rotated with different modes of action.

Characterization of prostatic carcinoma among blacks: A comparison between a low-incidence area, Ibadan, Nigeria, and a high-incidence area, Washington, DC

The Prostate ◽  
1980 ◽  
Vol 1 (2) ◽  
pp. 185-205 ◽  
Author(s):  
Marvin A. Jackson ◽  
Joseph Kovi ◽  
Martin Y. Heshmat ◽  
T. A. Ogunmuyiwa ◽  
George W. Jones ◽  
...  
Keyword(s):  
Prostatic Carcinoma ◽  
Washington Dc ◽  
High Incidence ◽  
Low Incidence ◽  
High Incidence Area ◽  
Ibadan Nigeria

scholarly journals Antibiotic prescribing during an outbreak of meningococcal disease

1996 ◽  
Vol 117 (1) ◽  
pp. 103-105 ◽  
Author(s):  
J. M. Stuart ◽  
P. M. Robinson ◽  
K. Cartwright ◽  
N. D. Noah
Keyword(s):  
Meningococcal Disease ◽  
Rate Ratio ◽  
Antibiotic Prescribing ◽  
Upper Respiratory Tract ◽  
Significant Difference ◽  
High Incidence ◽  
Resistant Strains ◽  
Upper Respiratory ◽  
Low Incidence ◽  
British Health

SummaryDuring a prolonged outbreak of meningococcal disease caused by serogroup B serotype 15 sulphonamide-resistant strains in one British health district, there was considerable variation in attack rates by town. General practitioner (GP) antibiotic prescribing rates were compared in high and low incidence towns. The only significant difference found was that erythromycin prescribing was more frequent in the high incidence towns (rate ratio 4·0, 95% CI 3·2–4·8, in March 1987 and 3·0, 95% CI 2·4–3·7, in November 1987). This was probably due to increased GP consultation rates for upper respiratory tract infection (URTI), but higher erythromycin usage may have increased meningococcal acquisition rates or susceptibility to meningococcal disease. Antibiotic prescribing rate should be further investigated in defined areas of high and low incidence of meningococcal disease.

scholarly journals Changes in the Sensitivity of Erwinia amylovora Populations to Streptomycin and Oxolinic Acid in Israel

Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 650-654 ◽  
Author(s):  
S. Manulis ◽  
F. Kleitman ◽  
D. Shtienberg ◽  
H. Shwartz ◽  
D. Oppenheim ◽  
...  
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Nationwide Survey ◽  
Streptomycin Resistance ◽  
Oxolinic Acid ◽  
Pome Fruit ◽  
Resistant Strains ◽  
Fruit Orchards

A survey of streptomycin resistance in the fire blight pathogen, Erwinia amylovora, conducted in pear, apple, and quince orchards in Israel during 1998 to 2001 revealed a decrease in the frequency of locations with streptomycin-resistant strains, from 57% in 1998 to 15% in 2001. In 2001, streptomycin-resistant strains were detected in only five locations in two restricted areas in western Galilee and the Golan Heights, compared with 16 locations found in 1998 throughout the northern part of the country. Since the use of streptomycin for fire blight control was terminated in 1997, this antibiotic has been replaced with oxolinic acid (Starner) in commercial orchards. Strains resistant to oxolinic acid were isolated from two pear orchards in the northern part of Israel in 1999. In a nationwide survey conducted during the spring and winter of 2000 and 2001, 51 and 47 pome fruit orchards, respectively, were sampled. Oxolinic acid-resistant strains were detected in several orchards located in two restricted areas in northern Galilee. Strains with resistance to both streptomycin and oxolinic acid were not found during 2000 to 2001. Results of this survey are used in managing fire blight with bactericides.

scholarly journals Exploring Diversity and Origins of Streptomycin-Resistant Erwinia amylovora Isolates in New York Through CRISPR Spacer Arrays

Plant Disease ◽  
2016 ◽  
Vol 100 (7) ◽  
pp. 1307-1313 ◽  
Author(s):  
K. A. Tancos ◽  
K. D. Cox
Keyword(s):  
United States ◽  
New York ◽  
Chemical Control ◽  
Erwinia Amylovora ◽  
The United States ◽  
Streptomycin Resistance ◽  
Western United States ◽  
Eastern United States ◽  
Bacterial Populations ◽  
Short Palindromic Repeat

Streptomycin is the most effective and widely used chemical control in the eastern United States for blossom blight of apple caused by Erwinia amylovora; however, resistance to this antibiotic has been a concern in New York since 2002. From 2011 to 2014, statewide collections of E. amylovora were conducted resulting in the isolation of streptomycin-resistant (SmR) E. amylovora from several commercial orchards. Further genetic analysis of isolates was necessary to understand the origins and the diversity of these bacteria. Clustered regularly interspaced short palindromic repeat (CRISPR) spacer sequencing was employed to explore the diversity and possible origins of New York SmR E. amylovora isolates. The spacer array CR1, CR2, and CR3 regions of 27 SmR E. amylovora isolates and 76 streptomycin-sensitive (SmS) E. amylovora isolates were amplified and subsequently sequenced, revealing 19 distinct CRISPR spacer profiles for New York isolates. The majority of SmR E. amylovora isolates had the same CRISPR profile as SmR E. amylovora isolates discovered in 2002. This may infer that eradication efforts in 2002 failed and the bacterial populations continued to spread throughout the state. Several CRISPR profiles for SmR E. amylovora were identical to SmS E. amylovora collected from the same orchards, leading to the hypothesis that resistance may be developing within New York. Profiles not unique to New York were identical to many isolates from the Midwestern, eastern, and western United States, implying that streptomycin resistance may be due to the introduction of SmR E. amylovora from other regions of the United States. The increased understanding as to how SmR E. amylovora isolates are introduced, evolve, or have become established afforded by CRISPR profiling has been useful for disease management and restricting the movement of streptomycin resistance in New York.

scholarly journals Molecular characterization of rpoB gene mutations in isolates from tuberculosis patients in Cubal, Republic of Angola

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ariadna Rando-Segura ◽  
María Luisa Aznar ◽  
María Milagros Moreno ◽  
Mateu Espasa Soley ◽  
Elena Sulleiro Igual ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Rpob Gene ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Resistance Pattern ◽  
Tuberculosis Patients ◽  
High Incidence ◽  
Resistant Strains

Abstract Background The importance of Mycobacterium tuberculosis strains with disputed rpoB mutations remains to be defined. This study aimed to assess the frequency and types of rpoB mutations in M. tuberculosis isolates from Cubal, Angola, a country with a high incidence of tuberculosis. Methods All isolates included (n = 308) were analyzed using phenotypic drug susceptibility testing and GenoType MTBDRplus assay. DNA sequencing of the rpoB gene and determination of rifampicin MIC by macrodilution method were additionally performed on isolates yielding discordant results (n = 12) and those in which the mutation detected was not characterized (n = 8). Results In total, 85.1% (74/87) of rifampicin-resistant strains had undisputed rpoB mutations -S450L (49), D435V (15), H445D (3), H445Y (2), Q432ins (1), L449M plus S450F (1), S450F (1), S450W (1) and S450Y (1)-; 10.3% (9/87) had disputed rpoB mutations—L430P plus S493L (1), N437del (1), H445L (3), D435Y (2), L452P (2)-, 2.3% (2.3%) showed no rpoB mutations and 2.3% (2/87) showed heteroresistance—D435Y plus L452P and L430P plus S493L-. Conclusion Disputed rpoB mutations were common, occurring in 10.3% of rifampicin resistant isolates. Current phenotyping techniques may be unable to detect this resistance pattern. To increase their sensitivity, a lower concentration of RIF could be used in these tests or alternatively, rpoB mutations could be screened and characterized in all M. tuberculosis strains.

scholarly journals Tetracycline and Streptomycin Resistance Genes, Transposons, and Plasmids in Salmonella enterica Isolates from Animals in Italy

2004 ◽  
Vol 48 (3) ◽  
pp. 903-908 ◽  
Author(s):  
Cristina Pezzella ◽  
Antonia Ricci ◽  
Elisabetta DiGiannatale ◽  
Ida Luzzi ◽  
Alessandra Carattoli
Keyword(s):  
Resistance Genes ◽  
Plant Pathogen ◽  
Salmonella Enterica ◽  
Insertion Sequence ◽  
Erwinia Amylovora ◽  
Multidrug Resistant ◽  
Streptomycin Resistance ◽  
Resistance Plasmids ◽  
Resistant Strains

ABSTRACT Fifty-eight multidrug-resistant Salmonella enterica strains of 20 serotypes, isolated from animal sources in Italy, were analyzed for tet(A) and strA-strB, conferring tetracycline and streptomycin resistance, respectively. The strA and strB genes were highly prevalent in Salmonella strains of our collection, being detected in 84% of the streptomycin-resistant strains. In many strains, the strA and strB genes were linked to a particular Tn5393-derivative transposon characterized by the presence of the insertion sequence IS1133, previously identified only in the plant pathogen Erwinia amylovora. Sixty-eight percent of the tetracycline-resistant strains were tet(A) positive, indicating that this gene is widely diffused in Salmonella strains circulating in animals in Italy. Most of the tet(A) genes were localized within a deleted Tn1721 transposon variant. Two prevalent repN and repI1 resistance plasmids were identified in Salmonella isolates of our collection.

Application of commercial test-systems to identify gram-negative facultatively anaerobic bacteria

2016 ◽  
Vol 3 (1) ◽  
pp. 43-48 ◽  
Author(s):  
V. Patyka ◽  
L. Butsenko ◽  
L. Pasichnyk
Keyword(s):  
Erwinia Amylovora ◽  
Anaerobic Bacteria ◽  
Biochemical Properties ◽  
Test System ◽  
Phytopathogenic Bacteria ◽  
Gram Negative ◽  
Test Systems ◽  
Facultatively Anaerobic ◽  
Microbiological Methods

Aim. To validate the suitability of commercial API 20E test-system (bioMerieux) for the identifi cation and characterization of facultative gram-negative phytopathogenic bacterial isolates. Methods. Conventional mi- crobiological methods, API 20E test-system (bioMerieux) according to the manufacturer’s instructions. Re- sults. The identifi cation results for Erwinia amylovora, Pectobacterium carotovorum and Pantoea agglome- rans isolates were derived from the conventional and API 20E test systems, which, were in line with the literature data for these species. The API 20E test-system showed high suitability for P. agglomerans isolates identifi cation. Although not all the species of facultatively anaerobic phytopathogenic bacteria may be identi- fi ed using API 20E test-system, its application will surely allow obtaining reliable data about their physiologi- cal and biochemical properties, valuable for identifi cation of bacteria, in the course of 24 h. Conclusions. The results of tests, obtained for investigated species while using API 20E test-system, and those of conventional microbiological methods coincided. The application of API 20E test-system (bioMerieux) ensures fast obtain- ing of important data, which may be used to identify phytopathogenic bacteria of Erwinia, Pectobacterium, Pantoea genera.

Fire Blight Susceptibility in Pyrus Germplasm from Eastern Europe

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 566-568 ◽  
Author(s):  
T. van der Zwet ◽  
R.L. Bell
Keyword(s):  
Eastern Europe ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Breeding Program ◽  
Plant Germplasm ◽  
Plant Exploration ◽  
Moderately Resistant

During 1976-1980, three plant exploration trips were made throughout eastern Europe in search of native Pyrus germplasm. A total of 384 accessions (231 from Yugoslavia, 86 from Romania, 43 from Poland, and 12 each from Hungary and Czechoslovakia) were collected as budwood and propagated at the National Plant Germplasm Quarantine Center in Glenn Dale, Md. Following 8 years of exposure to the fire blight bacterium [Erwinia amylovora (Burr.) Winsl. et al.], 17.49” of the accessions remained uninfected, 11.2% rated resistant, 6.8% moderately resistant, and 64.6% blighted severely (26% to 100% of tree blighted). Some of the superior accessions have been released for use in the pear breeding program.

scholarly journals Spatial distribution and risk assessment of toxic metals in agricultural soils from endemic nasopharyngeal carcinoma region in South China

2020 ◽  
Vol 12 (1) ◽  
pp. 568-579
Author(s):  
Liping Mo ◽  
Yongzhang Zhou ◽  
Gnanachandrasamy Gopalakrishnana ◽  
Xingyuan Li
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
South China ◽  
Toxic Metals ◽  
Agricultural Soils ◽  
Hazard Index ◽  
Toxic Metal ◽  
Carcinogenic Risk ◽  
Pollution Indices ◽  
High Incidence ◽  
Low Incidence

AbstractSihui city (South China) is much affected by nasopharyngeal carcinoma (NPC). To investigate the relationships between the toxic metals in soil and NPC incidence in Sihui, 119 surface soil samples were collected from agricultural fields and analyzed. The soil As–Cr contents in Longjiang (high-incidence area) are significantly lower than those in Weizheng and Jianglin (low-incidence areas), whereas the soil Pb content in Longjiang is significantly higher than that in Weizheng. The Nemerow pollution indices (PIN) of soils decrease in the order of Jianglin > Weizheng > Longjiang. The enrichment factor (EF) of Cd indicates that the Cd enrichment is contributed by human activities. Potential toxic metal-related ecological risk values decrease in the order of Jianglin > Weizheng > Longjiang. The mean hazard index (HI) value of Longjiang was lower than those of Weizheng and Jianglin. There are no adverse noncarcinogenic health effects of soil toxic metals to adults in the study areas. Carcinogenic risks of As and Cr via ingestion and dermal contact and total carcinogenic risk are within the warning range, from 10−6 to 10−4. Hence, we suggest that toxic metals in the soil may not be major geochemical carcinogenic factors of high NPC incidence in Sihui.

scholarly journals Identification and Characterization of Multiple Myeloma Stem Cell-Like Cells

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3523
Author(s):  
Wancheng Guo ◽  
Haiqin Wang ◽  
Peng Chen ◽  
Xiaokai Shen ◽  
Boxin Zhang ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Resistance ◽  
Stem Cell ◽  
New Drugs ◽  
Cell Therapies ◽  
High Relapse Rate ◽  
High Incidence ◽  
Poorly Differentiated ◽  
Identification And Characterization

Multiple myeloma (MM) is a B-cell tumor of the blood system with high incidence and poor prognosis. With a further understanding of the pathogenesis of MM and the bone marrow microenvironment, a variety of adjuvant cell therapies and new drugs have been developed. However, the drug resistance and high relapse rate of MM have not been fundamentally resolved. Studies have shown that, in patients with MM, there is a type of poorly differentiated progenitor cell (MM stem cell-like cells, MMSCs). Although there is no recognized standard for identification and classification, it is confirmed that they are closely related to the drug resistance and relapse of MM. This article therefore systematically summarizes the latest developments in MMSCs with possible markers of MMSCs, introduces the mechanism of how MMSCs work in MM resistance and recurrence, and discusses the active pathways that related to stemness of MM.

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