Molecular diagnostic of Ureaplasma urealyticum presence and tetracycline resistance in urine samples

Sexually transmitted infections (STIs) are among the most common infections in Romania. Infection with Ureaplasma urelyticum is one of the major causes of STIs and can cause serious complications. Although tetracycline is the drug commonly used to treat infections caused by U. urealyticum, several studies indicate the emergence and rapid development of strains resistant to these antibiotics in the United States or Europe. Tetracycline resistance in bacteria is encoded by a number of different genetic determinants but in mycoplasmas the only tetracycline resistance determinant that has been reported is the tetM gene. Tetracycline resistance among Ureaplasma spp. is associated with the presence of the horizontally acquired tetM resistance gene. Our study on bacterial DNA aimed to determine the presence of tetracycline-resistant U. urealyticum strains, by identifying the presence of the tetM gene. We used first void urine samples from 622 STI-suspected subjects. DNA was extracted, purified and amplified via PCR for the simultaneous detection of 6 STIs. 68 patients were diagnosed with U. urealyticum. DNA obtained from these samples was amplified using the tetM gene and U. urealyticum - specific urease gene primers. The urease gene was amplified in all samples, confirming the presence of U. urealyticum. The tetM gene was amplified in 2 samples considered tetracycline-resistant strains. The study confirmed the presence of U. urealyticum strains resistant to tetracycline in Romania. The employed technique can produce quick results both for U. urealyticum detection and determination of its resistance to tetracycline using a single easy-to-collect biological sample.

Isolation and molecular characterization of a urease-negative Actinobacillus pleuropneumoniae mutant

An atypical urease-negative mutant of Actinobacillus pleuropneumoniae serovar 2 was isolated in Japan. Nucleotide sequence analysis of the urease gene cluster revealed that the insertion of a short DNA sequence into the cbiM gene was responsible for the urease-negative activity of the mutant. Veterinary diagnostic laboratories should be watchful for the presence of aberrant urease-negative A. pleuropneumoniae isolates.

A Bacillus paralicheniformis Iron-Containing Urease Reduces Urea Concentrations in Rice Wine

ABSTRACT Urease, a nickel-containing metalloenzyme, was the first enzyme to be crystallized and has a prominent position in the history of biochemistry. In the present study, we identified a nickel urease gene cluster, ureABCEFGDH, in Bacillus paralicheniformis ATCC 9945a and characterized it in Escherichia coli. Enzymatic assays demonstrate that this oxygen-stable urease is also an iron-containing acid urease. Heterologous expression assays of UreH suggest that this accessory protein is involved in the transmembrane transportation of nickel and iron ions. Moreover, this iron-containing acid urease has a potential application in the degradation of urea in rice wine. The present study not only enhances our understanding of the mechanism of activation of urease but also provides insight into the evolution of metalloenzymes. IMPORTANCE An iron-containing, oxygen-stable acid urease from B. paralicheniformis ATCC 9945a with good enzymatic properties was characterized. This acid urease shows activities toward both urea and ethyl carbamate. After digestion with 6 U/ml urease, approximately 92% of the urea in rice wine was removed, suggesting that this urease has great potential in the food industry.