scholarly journals Genetic Characterization of Staphylococcus aureus From Subclinical Mastitis Cases in Dairy Cows in Rwanda

2021 ◽  
Vol 8 ◽  
Author(s):  
Jean Baptiste Ndahetuye ◽  
Mikael Leijon ◽  
Renée Båge ◽  
Karin Artursson ◽  
Ylva Persson
Keyword(s):  
Dairy Cows ◽  
Resistance Gene ◽  
Tetracycline Resistance ◽  
Subclinical Mastitis ◽  
Sequence Type ◽  
Penicillin Resistance ◽  
Phenotypic Resistance ◽  
The Third ◽  
Recent Transmission ◽  
Sequence Types

Whole-genome sequencing was carried out on 30 Staphylococcus (S.) aureus isolates from dairy cows with subclinical mastitis from all five provinces of Rwanda. Twenty-five of the isolates produced enough sequence to be analyzed using core genome multilocus sequence typing (cg-MLST). The isolates group into three main clusters. The largest cluster contain isolates of sequence type (ST) 152 (n = 6) and the closely related ST1633 (n = 2). These sequence types have previously mainly been encountered in humans. The isolates of the second-largest cluster belong to ST5477 (n = 5),so far exclusively isolated from cows in Rwanda. The third cluster consists of isolates of ST97 (n = 4), which is a well-known bovine-adapted sequence type. These three clusters were all widespread over the country. Isolates of the usually human-adapted sequence types 1 (n = 2) and 5 (n= 1) were found and a single isolate of ST2430, previously found among humans in Africa. Finally, four isolates of novel sequence types were found: ST7108 (n = 2), ST7109 (n = 1), and ST7110 (n = 1). The blaZ penicillin resistance gene was found in 84% of the isolates and was in all cases corroborated by phenotypic resistance determination. Five (20%) of the isolates carried a tetracycline resistance gene, tet(K) or tetM, and three of these five also displayed phenotypic resistance while two isolates carried a tetM-gene but were yet tetracycline susceptible. Seven (28%) isolates carried the dfrG gene conferring resistance to trimethoprim. Four of these isolates indeed were resistant to trimethoprim while three isolates were sensitive. The str gene conferring resistance to aminoglycosides was found in three isolates; however, none of these displayed resistance to gentamycin. Our data revealed a high diversity of the sequence types of S. aureus isolates from cows with subclinical mastitis in Rwanda. Two major clusters of ST97 and ST5477 are likely to be bovine adapted and cause mastitis while the third cluster of ST152 usually have been found in humans and may signify a recent transmission of these types from human to cows, for example from hand milking. The high prevalence of this sequence type among dairy cows may pose zoonotic threat. The sequence types were widely distributed without any geographic correlation. Penicillin resistance, the most common type of resistance with a prevalence over 80%, but also tetracycline and trimethoprim resistance were displayed by several isolates.

scholarly journals Molecular Characterization of Pneumococci with Efflux-Mediated Erythromycin Resistance and Identification of a Novel mef Gene Subclass, mef(I)

2005 ◽  
Vol 49 (12) ◽  
pp. 4999-5006 ◽  
Author(s):  
Ileana Cochetti ◽  
Manuela Vecchi ◽  
Marina Mingoia ◽  
Emily Tili ◽  
Maria R. Catania ◽  
...  
Keyword(s):  
Tetracycline Resistance ◽  
Sequence Type ◽  
Open Reading Frames ◽  
Resistant Isolate ◽  
Pfge Type ◽  
Polymorphism Analysis ◽  
Erythromycin Resistance ◽  
M Gene ◽  
Sequence Types

ABSTRACT The molecular genetics of macrolide resistance were analyzed in 49 clinical pneumococci (including an “atypical” bile-insoluble strain currently assigned to the new species Streptococcus pseudopneumoniae) with efflux-mediated erythromycin resistance (M phenotype). All test strains had the mef gene, identified as mef(A) in 30 isolates and mef(E) in 19 isolates (including the S. pseudopneumoniae strain) on the basis of PCR-restriction fragment length polymorphism analysis. Twenty-eight of the 30 mef(A) isolates shared a pulsed-field gel electrophoresis (PFGE) type corresponding to the England14-9 clone. Of those isolates, 27 (20 belonging to serotype 14) yielded multilocus sequence type ST9, and one isolate yielded a new sequence type. The remaining two mef(A) isolates had different PFGE types and yielded an ST9 type and a new sequence type. Far greater heterogeneity was displayed by the 19 mef(E) isolates, which fell into 11 PFGE types, 12 serotypes (though not serotype 14), and 12 sequence types (including two new ones and an undetermined type for the S. pseudopneumoniae strain). In all mef(A) pneumococci, the mef element was a regular Tn1207.1 transposon, whereas of the mef(E) isolates, 17 carried the mega element and 2 exhibited a previously unreported organization, with no PCR evidence of the other open reading frames of mega. The mef gene of these two isolates, which did not match with the mef(E) gene of the mega element (93.6% homology) and which exhibited comparable homology (91.4%) to the mef(A) gene of the Tn1207.1 transposon, was identified as a novel mef gene variant and was designated mef(I). While penicillin-nonsusceptible isolates (three resistant isolates and one intermediate isolate) were all mef(E) strains, tetracycline resistance was also detected in three mef(A) isolates, due to the tet(M) gene carried by a Tn916-like transposon. A similar mechanism accounted for resistance in four of the five tetracycline-resistant isolates carrying mef(E), in three of which mega was inserted in the Tn916-like transposon, giving rise to the composite element Tn2009. In the fifth mef(E)-positive tetracycline-resistant isolate (the S. pseudopneumoniae strain), tetracycline resistance was due to the presence of the tet(O) gene, apparently unlinked to mef(E).

scholarly journals Identification of a Novel Trimethoprim Resistance Gene, dfrK, in a Methicillin-Resistant Staphylococcus aureus ST398 Strain and Its Physical Linkage to the Tetracycline Resistance Gene tet(L)

2008 ◽  
Vol 53 (2) ◽  
pp. 776-778 ◽  
Author(s):  
Kristina Kadlec ◽  
Stefan Schwarz
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Dihydrofolate Reductase ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tetracycline Resistance ◽  
Sequence Type ◽  
Tetracycline Resistance Gene ◽  
Close Proximity ◽  
Physical Linkage ◽  
Dihydrofolate Reductases

ABSTRACT A novel trimethoprim resistance gene, designated dfrK, was detected in close proximity to the tetracycline resistance gene tet(L) on the ca. 40-kb plasmid pKKS2187 in a porcine methicillin (meticillin)-resistant Staphylococcus aureus isolate of sequence type 398. The dfrK gene encodes a 163-amino-acid dihydrofolate reductase that differs from all so-far-known dihydrofolate reductases.

scholarly journals Identification of a Plasmid-Borne Resistance Gene Cluster Comprising the Resistance Genes erm(T), dfrK, and tet(L) in a Porcine Methicillin-Resistant Staphylococcus aureus ST398 Strain

2009 ◽  
Vol 54 (2) ◽  
pp. 915-918 ◽  
Author(s):  
Kristina Kadlec ◽  
Stefan Schwarz
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Resistance Gene ◽  
Streptococcus Pyogenes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tetracycline Resistance ◽  
Sequence Type ◽  
The Novel ◽  
Methicillin Resistant ◽  
Resistance Gene Cluster

ABSTRACT A novel plasmid-borne resistance gene cluster comprising the genes erm(T) for macrolide-lincosamide-streptogramin B resistance, dfrK for trimethoprim resistance, and tet(L) for tetracycline resistance was identified in a porcine methicillin-resistant Staphylococcus aureus sequence type 398 (ST398) strain. This erm(T)-dfrK-tet(L) region was flanked by copies of the novel IS element ISSau10. The erm(T) region resembled that of Streptococcus pyogenes plasmid pRW35. The erm(T) gene of pKKS25 was expressed constitutively due to a 57-bp deletion in the erm(T) translational attenuator.

scholarly journals Identification of Streptococcus uberis Multilocus Sequence Types Highly Associated with Mastitis

2007 ◽  
Vol 74 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Takehiro Tomita ◽  
Brian Meehan ◽  
Nalin Wongkattiya ◽  
Jakob Malmo ◽  
Gillian Pullinger ◽  
...  
Keyword(s):  
Clonal Complex ◽  
Subclinical Mastitis ◽  
Sequence Type ◽  
Empirical Estimation ◽  
Somatic Cell Counts ◽  
Streptococcus Uberis ◽  
Cell Counts ◽  
Standardized Index ◽  
First Time ◽  
Sequence Types

ABSTRACT Multilocus sequence typing analysis of Streptococcus uberis has identified a cluster of isolates associated with clinical and subclinical mastitis and a cluster associated with cows with low somatic cell counts in their milk. Specific groups of genotypes (global clonal complex [GCC] sequence type 5s [ST5s] and GCC ST143s) were highly associated (P = 0.006) with clinical and subclinical mastitis and may represent a lineage of virulent isolates, whereas isolates belonging to GCC ST86 were associated with low-cell-count cows. This study has, for the first time, demonstrated the occurrence of identical sequence types (ST60 and ST184) between different continents (Australasia and Europe) and different countries (Australia and New Zealand). The standardized index of association and the empirical estimation of the rate of recombination showed substantial recombination within the S. uberis population in Australia, consistent with previous multilocus sequence type analyses.

scholarly journals Plasmids of Diverse Inc Groups Disseminate the Fosfomycin Resistance Gene fosA3 among Escherichia coli Isolates from Pigs, Chickens, and Dairy Cows in Northeast China

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Xiu-Mei Wang ◽  
Zhimin Dong ◽  
Stefan Schwarz ◽  
Yao Zhu ◽  
Xin Hua ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Resistance Gene ◽  
Northeast China ◽  
Sequence Type ◽  
Content Type ◽  
E Coli ◽  
Conjugative Plasmids ◽  
Fosfomycin Resistance

ABSTRACT Thirty-nine fosfomycin-resistant Escherichia coli isolates carrying fosA3 were obtained from pigs, chickens, dairy cows, and staff in four northeastern provinces of China between June 2015 and April 2016. The fosA3 gene was colocated with bla CTX-M genes on conjugative plasmids of the incompatibility groups IncN (n = 12), IncN-F33:A−:B−(n = 2), IncF33:A−:B−(n = 14), IncF14:A−:B−(n = 2), and IncI1/sequence type 136 (ST136) (n = 9). Four different genetic contexts of fosA3 were detected among the 39 E. coli isolates. Three potential epidemic plasmids circulated among E. coli strains from this region.

Characterisation of penicillin and tetracycline resistance in Staphylococcus aureus isolated from bovine milk samples in Minas Gerais, Brazil

2017 ◽  
Vol 84 (2) ◽  
pp. 202-205 ◽  
Author(s):  
Caroline L Martini ◽  
Carla C Lange ◽  
Maria AVP Brito ◽  
João B Ribeiro ◽  
Letícia C Mendonça ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Bovine Milk ◽  
Bovine Mastitis ◽  
Tetracycline Resistance ◽  
Subclinical Mastitis ◽  
Minas Gerais ◽  
Beta Lactamase ◽  
Phenotypic Resistance ◽  
Minas Gerais State

This Regional Research Communication describes the characterisation of ampicillin, penicillin and tetracycline resistance in Staphylococcus aureus isolated from bovine subclinical mastitis in Minas Gerais State, Brazil. Ninety S. aureus isolates from bovine mastitis exhibiting phenotypic resistance to ampicillin, penicillin and/or tetracycline were selected for this study. The minimum inhibitory concentration (MIC) of each antibiotic was determined using the E-Test® and the production of beta-lactamase was determined by cefinase disks. The resistance genes blaZ, tet(K), tet(L), tet(M), and tet(O) were investigated by PCR in all of the isolates. The MIC results classified 77, 83 and 71% of the isolates as resistant to ampicillin, penicillin and tetracycline, respectively. The MIC50 and MIC90 were, respectively, 1 and 2 µg/ml for ampicillin, 0·5 and 1 µg/ml for penicillin and 32 and 64 µg/ml for tetracycline. Eighty-six per cent of beta-lactamase producing isolates were detected. Of the 90 isolates investigated, 97% amplified blaZ, 84% amplified tet(K), 9% amplified tet(L), 2% amplified tet(M) and 1% amplified tet(O). Seventy-nine isolates (88%) showed blaZ together with at least one tet gene. S. aureus isolates showed high MIC50 and MIC90 values for the three antimicrobials. The blaZ and tet(K) genes were widespread in the herds studied, and most of the isolates harboured blaZ and tet(K) concomitantly.

scholarly journals Effects of a Direct-Fed Microbial and Feedlot Pen Environmental Change on Phenotypic Resistance among Enterococci Isolated from Beef Cattle Feces

2021 ◽  
Author(s):  
Sarah A. Murray ◽  
Ashlyn C. Holbert ◽  
Keri N. Norman ◽  
Sara D. Lawhon ◽  
Jason E. Sawyer ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Beef Cattle ◽  
Resistance Genes ◽  
Enterococcus Faecium ◽  
Sequence Type ◽  
Whole Genome ◽  
Fecal Samples ◽  
Phenotypic Resistance ◽  
The Impact ◽  
Sequence Types

In two sequential replicates (n=90 and n=96 feedlot finisher cattle, respectively) we measured the impact of an Enterococcus faecium-based probiotic (DFM) and an altered feedlot pen environment on antimicrobial resistance among fecal enterococci in cattle fed (or, not fed) the macrolide tylosin. Diluted fecal samples were spiral-plated on plain and antibiotic-supplemented m-Enterococcus agar. In the first replicate, tylosin significantly (p<0.05) increased the relative quantity of erythromycin-resistant enterococci. This effect was diminished in cattle fed the DFM in conjunction with tylosin. A similar observed effect was not statistically significant (P > 0.05) in the second replicate. Isolates were speciated and resistance phenotypes were obtained for E. faecium and E. hirae. E. faecium isolates were whole-genome sequenced, which yielded sequence types (ST), resistance genes and phylogeny. Samples of the DFM were sequenced and found to contain E. faecium ST296, which was not present on Day 0 of either replicate. This DFM sequence type was found in fecal samples after Day 0, the majority of which were isolated from cattle in one of the DFM-fed pens. Increased prevalence of ST296 occurred with a concomitant decrease in ST240; of importance, the latter typically harbored both ermB and tet(M) genes.

LIME AND DAIRY PRODUCTION

1982 ◽  
pp. 93-103
Author(s):  
N.A. Thomson
Keyword(s):  
Soil Moisture ◽  
Dairy Cows ◽  
Milk Production ◽  
Soil Ph ◽  
Dairy Production ◽  
Pasture Production ◽  
The Third ◽  
One Year ◽  
Plasma Magnesium

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime

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