Epidemiological characteristics and drug resistance of Salmonella isolated from diarrhea patients in Jiading District of Shanghai / 上海预防医学

Objective:To analyze the epidemiological characteristics and drug resistance of Salmonella in patients with food-borne diarrhea in Jiading District. Methods:From January 2018 to December 2019， feces or anal swabs of patients were collected from five hospitals in monitoring sites， and the drug sensitivity test was conducted using the micro broth dilution method. Results:The total detection rate of Salmonella was 7.85% （142/1 810）， and the detection rates of 0-6， 7-17， 18-40， 41-65 and over 65 years old were 8.97% （13/145）， 6.94% （5/72）， 7.58% （75/989）， 8.69% （41/472） and 6.06% （8/132）， respectively. Salmonella rosenbergii was a new dominant serotype in this area. Many strains were resistant to the third and fourth generation cephalosporins， fluoroquinolones and even azithromycin. The sensitivity rate of Salmonella typhimurium to cefotaxime and cefepime was 84.85%， and the resistance rate to fluoroquinolones was 12% to 16%. The mediating rates of Salmonella and Salmonella enteritidis to fluoroquinolones were 56% to 60% and 95.56%， respectively. Conclusion:The detection rate of Salmonella infection is high in all age groups. It is necessary to pay more attention to new dominant serotypes. Salmonella typhimurium is highly resistant to the third and fourth generation cephalosporins and fluoroquinolones， while the sensitivity of Salmonella， especially Salmonella enteritidis to fluoroquinolones has decreased significantly.

Construction of sRNA-deficient and-overexpressing strains of Yersinia pestis / 军事医学

Objective To construct small RNA deletion and overexpression strains with a length of less than 100 nt in Yersinia pestis.Methods Deletion mutants of the target sRNAs were constructed by increasing the length of homologous regions.Meanwhile, the high copy plasmid pBAD/HisA was modified into an inducible transcriptional vector as an sRNA-overexpression plasmid by using QuikChange lightning site-directed mutagenesis kit .The presence , size, and transcription-al initiation sites of the indicated sRNA were predicted by transcriptome sequencing , primer extension , and previous stud-ies.The full-length DNA fragments of target sRNAs were transformed into the transcriptional vector .The overexpressing strains of sRNAs were identified by Northern Blot .Results and Conclusion Four sRNAs deletion mutants of sR01, sR02, sR03 and HmsA and three sRNAs overexpression mutants MicF , HmsA and CpxQ were successfully constructed .A method of construction of sRNA deficient and overexpressing strains of Y.pestis has been quickly and efficiently established by λ-Red homologous recombination technology and QuikChange ? lightning site-directed mutagenesis kit.

Microwave radiation decreases the expressions of occludin and JAM-1 in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the changes in the expressions of the tight junction related protein occludin and junctional adhesion molecule-1 (JAM-1) of the blood-testis barrier and their significance in rats after microwave radiation.</p><p><b>METHODS</b>Eighty male Wistar rats were exposed to microwave radiation with average power density of 0, 10, 30 and 100 mW/cm2 for five minutes, and dynamic changes in the expressions of testicular occludin and JAM-1 were observed by Western blot and image analysis at 6 h, 1 d, 3 d, 7 d and 14 d after the radiation.</p><p><b>RESULTS</b>There was a significant down-regulation in the expression of the occludin protein at 3 - 7 d, 6 h - 7 d and 6 h - 14 d (P < 0. 05), as well as in that of JAM-1 at 3 - 7 d, 1 - 7 d and 1-14 d (P < 0.05) after exposure to 10, 30 and 100 mW/cm2 microwave radiation.</p><p><b>CONCLUSION</b>The decreased protein expressions of occludin and JAM-1 may play an important role in the microwave radiation induced-damage to the blood-testis barrier.</p>

Effect of microwave radiation on primary cultured Sertoli cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore whether microwave radiation may cause injury of primary cultured Sertoli cells.</p><p><b>METHODS</b>The model of primary cultured Sertoli cells in vitro was established, which was radiated by microwave with average power density 0, 30 and 100 mW/cm(2) for five minutes. The changes of cell cycle, apoptosis and death, and intracellular Ca2+ concentration in the Sertoli cells were measured at sixth hours through Annexin V-PI double labeling and Fluo-3-AM labeling, flow cytometry combined with laser scanning confocal microscopy after microwave exposure.</p><p><b>RESULTS</b>The numbers of Sertoli cells were obviously reduced in G0-G1 and G2-M phase (62.57% +/- 3.22% and 8.25% +/- 1.75%) and increased in S phase (29.17% +/- 4.87%) compared with the control groups (79.18% +/- 0.24%, 11.17% +/- 0.50% and 9.64% +/- 0.62%) (P < 0.05 or P < 0.01), but the changes of rate of apoptosis and death and intracellular Ca2+ concentration showed no difference at 6 h after exposure to 30 mW/cm(2) microwave. There was a significant increase in the Sertoli cell counts of G0-G1 phase (87.69% +/- 1.32%), and decrease in the Sertoli cell counts of G2-M and S phase (7.41% +/- 0.60% and 4.87% +/- 0.91%) (P < 0.01). There was also a significant increase in intracellular Ca2+ concentration and rate of apoptosis and death (P < 0.05 or P < 0.01) at 6 h after exposure to 100 mW/cm(2) microwave.</p><p><b>CONCLUSION</b>100 mW/cm(2) microwave radiation may cause growth inhibition and increase of apoptosis and death in the primary cultured Sertoli cells. The increase of intracellular Ca2+ concentration is one of the injury mechanisms.</p>

High power microwave radiation damages blood-testis barrier in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To determine the effect of high power microwave (HPM) radiation on the structure and function of blood-testis barrier (BTB) in rats.</p><p><b>METHODS</b>One hundred and sixty-six male Wistar rats were treated by heart perfusion of lanthanum-glutaraldehyde solution and tail vein injection of evans blue (EB) at 6 h, 1, 3, 7 and 14 d after exposed to 0, 10, 30 and 100 mW/cm2 HPM radiation for 5 minutes, the structural change of BTB and distribution of lanthanum or EB observed through the light microscope, electron microscope and laser scanning confocal microscopy (LSCM).</p><p><b>RESULTS</b>Testicular interstitial edema, vascular congestion or hyperemia with accumulation of plasma proteins and red blood cells in the inner compartment of seminiferous tubules were observed after exposure to HPM. The above-mentioned pathological changes were aggravated at 1-7 d and relieved at 14 d after radiation, obviously more severe in the 30 and 100 mW/cm2 exposure groups than in the 10 mW/cm2. Both lanthanum precipitation and EB were deposited in the inner compartment.</p><p><b>CONCLUSION</b>HPM radiation may damage the structure and increase the permeability of BTB.</p>

Status quo of the researches on the biological effect of electromagnetic radiation on the testis and epididymal sperm / 中华男科学杂志

The testis is highly sensitive to electromagnetic radiation. Sperm is the passer of male genetic material and electromagnetic radiation may cause structural and functional injury to the testis, including motility reduction, abnormality increase and ultrastructural alteration of epididymal sperm. Energy metabolism disorder in spermatogenic cells, enhancement of lipid peroxidation in the testis, excessive expression of inflammatory factors and abnormality of genetic transcription may be responsible for injury to the testis and epididymal sperm. This paper reviews the progress made in this field and the preventive measures against the injury.