ABSTRACT
In August 2021, three students with diarrhea from the same school visited a local hospital in the S district of Beijing. An epidemic investigation showed that there were more students with diarrhea in the same school and they had one meal together. Campylobacter jejuni was isolated from both patients with diarrhea and asymptomatic food handlers; however, the latter also carried Campylobacter coli. Phylogenomic analysis showed that there was a campylobacteriosis outbreak among the students, and the asymptomatic food handler may have been the source of the infection. Routine inspection and surveillance for Campylobacter is needed for the food producing staff, particularly those cooking in the cafeteria in schools or other public food services.
Subject(s)
Campylobacter Infections , Campylobacter , Gastroenteritis , Humans , Campylobacter Infections/epidemiology , Diarrhea , Disease OutbreaksABSTRACT
RlmM is an AdoMet-dependent methyltransferase that is responsible for 2'-O-methylation of C2498 in the peptidyl-transferase loop of bacterial 23S rRNA. This modification occurs before assembly of the 50S ribosomal subunit, and lack of C2498 methylation can cause a slight reduction in bacterial fitness. Here, the purification and crystallization of RlmM from Escherichia coli as well as its preliminary crystallographic analysis are presented. Cocrystallization of RlmM with AdoMet was carried out and X-ray diffraction data were collected to a resolution of 2.30 Å on beamline BL17U at the SSRF. However, electron density for AdoMet cannot be observed by comprehensive crystallographic analysis, indicating that it is not bound by RlmM during the cocrystallization process. The structure was solved by molecular replacement and refinement is in progress. The crystal contained one molecule in the asymmetric unit and belonged to space group P2(1), with unit-cell parameters a = 56.07, b = 59.38, c = 54.35 Å, ß = 94.84°, which differs from the P3(1) or P3(1)21 space groups of previously reported RlmM structures (PDB entries 4auk, 4atn and 4b17).
Subject(s)
Crystallography, X-Ray , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/isolation & purification , Escherichia coli , Methyltransferases/chemistry , Methyltransferases/isolation & purification , RNA, Ribosomal, 23S/chemistry , RNA, Ribosomal, 23S/isolation & purification , X-Ray DiffractionABSTRACT
<p><b>OBJECTIVE</b>To study the distribution of FASL-844 polymorphism in southern Chinese males of Han nationality and examine the contribution of the polymorphism to susceptibility of idiopathic azoospermia and oligozoospermia.</p><p><b>METHODS</b>FASL-844 polymorphism was genotyped by polymerase chain reaction and restriction fragment length polymorphism(PCR-RFLP) in 184 infertile patients with idiopathic azoospermia or severe oligozoospermia 236 normal fertile male controls.</p><p><b>RESULTS</b>Frequencies of FASL-844 CT and TT genotypes of the patients were significantly different from those of the controls (P = 0.024; P = 0.008). Males with FASL-844 TT genotype had an increased risk of idiopathic azoospermia or severe oligozoospermia compared with those with CC genotype (OR 2.76, 95% CI: 1.20-6.35), and even a higher risk when compared with those with CC and CT genotypes (OR 2.90, 95% CI: 1.28-6.58).</p><p><b>CONCLUSION</b>FASL-844 polymorphism appears to be a genetic predisposing factor of idiopathic azoospermia or severe oligozoospermia among southern Chinese Han males.</p>
