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The multiresistance gene cfr was found in two porcine Escherichia coli isolates, one harboring it on the conjugative 33,885-bp plasmid pFSEC-01, the other harboring it in the chromosomal DNA. Sequence analysis of pFSEC-01 revealed that a 6,769-bp fragment containing the cfr gene bracketed by two IS26 elements was inserted into a plasmid closely related to pEA3 from the plant pathogen Erwinia amylovora, suggesting that pFSEC-01 may be transferred between different bacterial genera of both animal and plant origin. The multiresistance gene cfr confers resistance to phenicols, lincosamides, pleuromutilins, streptogramin, and oxazolidinones and decreased susceptibility to the 16-membered macrolides spiramycin and josamycin (1-3). While the cfr gene is found mainly in Gram-positive bacteria (4), it has also been detected in two species of Gram-negative bacteria, Proteus vulgaris and Escherichia coli, during recent years (5-10). Here, we report IS26-flanked cfr genes from porcine E. coli are located either on a plasmid that most likely originated from the plant pathogen Erwinia amylovora or in the chromosomal DNA.During July and August 2013, a total of 396 samples were collected from the lungs of diseased animals (pigs, n ϭ 334; chickens, n ϭ 40; ducks, n ϭ 22) at an animal diagnostic laboratory at Foshan University, Foshan City, Guangdong, China. A total of 64 E. coli isolates grew on MacConkey agar plates supplemented with 10 mg/liter florfenicol. Of these, only two isolates, FSEC-01 and FSEC-02, which were obtained from swine suffering from pneumonia and sepsis, respectively, that originated from two different pig farms were positive for the cfr gene by PCR as described previously (11, 12).In vitro susceptibility testing (13,14) showed that isolates FSEC-01 and FSEC-02 were resistant to chloramphenicol, ampicillin, tetracycline, gentamicin, and streptomycin and also had high MIC values of florfenicol (128 g/ml). Isolate FSEC-02 also exhibited resistance to amoxicillin-clavulanic acid and sulfamethoxazole. In addition to harboring the cfr gene, both isolates harbored the phenicol exporter gene floR, the ␤-lactam resistance gene bla TEM-1 , and the tetracycline resistance gene tet(A). Isolate FSEC-01 also carried the aminoglycoside resistance gene aacC2 and the ␤-lactam resistance gene bla CTX-M-65 , whereas isolate FSEC-02 also harbored the aminoglycoside resistance genes aac(3)-VI, aadA2, aacC3, strA, and strB, the sulfonamide resistance gene sul2, and the ␤-lactam resistance gene bla (Table 1). S1 nuclease pulsed-field gel electrophoresis (PFGE) and Southern blot analysis (15) showed that the cfr gene was located on an ϳ34-kb plasmid, designated pFSEC-01, in isolate FSEC-01 and in the chromosomal DNA of isolate FSEC-02 (see Fig. S1 in the supplemental material). Conjugation experiments by filter mating (15) using isolate FSEC-01 as the donor and E. coli C600 as the recipient proved to be successful. The transconjugant, designated EC-600-FS-01, which harbored only the cfr-carrying plasmid pFSEC-01, was negative fo...

The aim of this study is to understand the prevalence and molecular characterization of 16S rRNA methylase gene, rmtB, among Escherichia coli strains isolated from bovine mastitis in China. A total of 245 E. coli isolates were collected from bovine mastitis in China between 2013 and 2014 and were screened for 16S rRNA methylase genes (armA, rmtA, rmtB, rmtC, rmtD, rmtE, and npmA) by polymerase chain reaction. About 5.3% (13/245) of the isolates carried the rmtB gene; the isolates were highly resistant to amikacin. Thirteen rmtB-positive strains were analyzed for the presence of extended-spectrum β-lactamase genes (bla(TEM), bla(CTX-M), bla(OXA), and bla(SHV)). All the isolates harbored both bla(TEM-1) and bla(CTX-M-15) genes and two of the isolates were also positive for bla(OXA-1). Pulsed-field gel electrophoresis (PFGE) analysis indicated that the nine rmtB-positive strains belonging to ST10 from one farm showed the similar PFGE pattern, indicating a clonal expansion in this farm. S1-PFGE and Southern blotting showed that 12 isolates harbored the rmtB gene in plasmids of two different sizes (≈45 kb [n=10] and ≈48 kb [n=2]), while only 1 strain harbored the rmtB gene in the chromosome. These plasmids were transferable by conjugation studies, and two isolates from two respective farms carried the same size of plasmid, suggesting that the horizontal transmission of plasmids also contributed to the spread of rmtB gene. This is the first report of prevalence of the 16S rRNA methylase gene rmtB among E. coli isolated from bovine mastitis in China, and rmtB-carrying E. coli may pose a threat to the treatment of bovine mastitis.

The retroperitoneal approach is reliable and safe for treating Cushing's syndrome. The laparoscopic technique can decrease the prevalence of intraoperative complications. Retroperitoneal laparoscopic partial adrenalectomy can be performed with extremely low morbidity and achieves an excellent outcome, although death may occur during the postoperative period in high-risk patients. Postoperative management plays an important role in the surgical treatment of Cushing's syndrome.