Antimicrobial resistance (AMR) is a major threat to global health. Understanding the emergence, evolution, and transmission of individual antibiotic resistance genes (ARGs) is essential to develop sustainable strategies combatting this threat. Here, we use metagenomic sequencing to analyse ARGs in 757 sewage samples from 243 cities in 101 countries, collected from 2016 to 2019. We find regional patterns in resistomes, and these differ between subsets corresponding to drug classes and are partly driven by taxonomic variation. The genetic environments of 49 common ARGs are highly diverse, with most common ARGs carried by multiple distinct genomic contexts globally and sometimes on plasmids. Analysis of flanking sequence revealed ARG-specific patterns of dispersal limitation and global transmission. Our data furthermore suggest certain geographies are more prone to transmission events and should receive additional attention.

CONTEXT:Artificial reproductive techniques using seminal preparations with bacteria may cause pelvic inflammatory disease and its sequalae.AIMS:To assess efficacy of two sperm preparation techniques to clear bacteria and the effect of bacteriospermia on sperm recovery rates.SETTINGS AND DESIGN:A descriptive cross-sectional study was carried out among males of subfertile couples.SUBJECTS AND METHODS:Semen samples were randomly allocated into swim-up method (group S, n = 68) and density gradient method (group D, n = 50) for sperm preparation. Seminal fluid analysis and bacterial cultures were performed in each sample before and after sperm preparation.STATISTICAL ANALYSIS:McNemar's chi-squared test and independent samples t-test in SPSS version 16.0 were used.RESULTS:Organisms were found in 86 (72.88%) out of 118 samples, before sperm preparation; Streptococcus species (n = 40, 46.51% of which 14 were Group D Streptococcus species), Coagulase negative Staphylococcus species (n = 17, 19.76%), Staphylococcus aureus (n = 13, 15.11%), Coliform species (n = 11, 12.79% of which 09 were Escherichia coli) and Corynebacterium species (n = 5, 5.81%). There was a statistically significant reduction of culture positive samples in raw vs. processed samples; in group S, 49 (72.05%) vs. 16 (23.52%) and in group D, 37 (74%) vs. 18 (36%). In group S and D, mean (SD) recovery rates of culture positive vs. culture negative samples were 39.44% (SD-14.02) vs. 44.22% (SD-22.38), P = 0.39 and 52.50% (SD-37.16) vs. 49.58% (SD-40.32), P = 0.82 respectively.CONCLUSIONS:Both sperm preparation methods significantly reduced bacteria in semen, but total clearance was not achieved. Sperm recovery rate was not affected by bacteriospermia.

RATIONALE:Bacterial flora can be isolated from many semen samples of subfertile males. Bacteriospermia can compromise the outcome of intra uterine insemination (IUI) by contaminating the post-processed sperm sample.OBJECTIVES:The objective of the present study is to determine the efficacy of penicillin and streptomycin in eliminating the bacteria from semen samples in the sperm processing procedure, and to assess the effects of antibiotics on sperm motility, survivability, and pregnancy rates.DESIGN AND SETTINGS:A prospectively controlled study was carried out using couples undergoing IUI with their informed consent.INTERVENTION:Sperm processing using the swim-up technique in penicillin and streptomycin supplemented culture medium.SUBJECTS AND METHODS:Couples were consecutively allocated in two groups for sperm processing (a) Group AB+ (antibiotics supplemented culture medium, n = 33) and (b) Group AB− (antibiotic free culture medium, n = 33). Semen culture was performed before and after sperm processing. Sperm motility was assessed immediately after processing and after 24 h of incubation.RESULTS:Bacterial isolates were found in 20 (60.6%) and 22 (66.1%) of samples before processing in Groups AB+ and AB− respectively. Addition of antibiotics resulted in completely eliminating non-specific bacteria from semen samples without affecting sperm motility. In vitro survival rate of sperm enhanced in AB+ group compared with AB− group (motile sperm after 24 h), 62.21% (standard deviation [SD]: 37.27) versus 41.36% (SD: 30.78), P = 0.012. Pregnancy rate, was comparable between two groups (9% in Group AB+ vs. 6% in Group AB−, P = 0.45).CONCLUSION:Penicillin streptomycin combination could completely eliminate non-specific bacteria from semen samples during sperm processing in this population. The types of antibiotics and dosage used did not seem to have any harmful effects on human sperm.