Background. Recurrent vulvovaginal infections are a frequent complaint in young women in need of contraception. However, the influence of the contraceptive method on the course of the disease is not well known.
Aim. To investigate the influence of the levonorgestrel-releasing intrauterine-system (LNG-IUS) on the vaginal microflora.
Methods. Short-term (3 months) and long-term (1 to 5 years) changes of vaginal microbiota were compared with pre-insertion values in 252 women presenting for LNG-IUS insertion. Detailed microscopy on vaginal fluid was used to define lactobacillary grades (LBGs), bacterial vaginosis (BV), aerobic vaginitis (AV) and the presence of Candida. Cultures for enteric aerobic bacteria and Candida were used to back up the microscopy findings. Fisher's test was used to compare vaginal microbiome changes pre- and post-insertion.
Results. Compared to the pre-insertion period, we found a temporary worsening in LBGs and increased rates of BV and AV after 3 months of LNG-IUS. After 1 and 5 years, however, these changes were reversed, with a complete restoration to pre-insertion levels. Candida increased significantly after long-term carriage of LNG-IUS compared to the period before insertion [OR 2.0 (CL951.1–3.5), P=0.017].
Conclusions. Short-term use of LNG-IUS temporarily decreases lactobacillary dominance, and increases LBG, AV and BV, but after 1 to 5 years these characteristics return to pre-insertion levels, reducing the risk of complications to baseline levels. Candida colonization, on the other hand, is twice as high after 1 to 5 years of LNG-IUS use, making it less indicated for long-term use in patients with or at risk for recurrent vulvovaginal candidosis.
Purpose. Virulent genotypes of Helicobacter pylori vacA s1m1/cagA+/babA2+ have been associated with severe gastric diseases. VacA, CagA and BabA are polymorphic proteins, and their association with the disease is allele-dependent. The aims of this work were: (i) to determine the prevalence of H. pylori by type of chronic gastritis; (ii) to describe the frequency of cagA, babA2 and vacA genotypes in strains from patients with different types of chronic gastritis; (iii) to characterize the variable region of cagA alleles.
Methodology. A total of 164 patients with chronic gastritis were studied. Altogether, 50 H. pylori strains were isolated, and the status of cagA, babA2 and vacA genotypes was examined by PCR. cagA EPIYA segment identification was performed using PCR and sequencing of cagA fragments of six randomly selected strains.
Results/Key findings. The overall prevalence of H. pylori was 30.5 %. Eighty percent of the isolated strains were vacA s1m1, and the cagA and babA2 genes were detected in 74 and 32 % of the strains, respectively. The most frequent genotypes were vacA s1m1/cagA+/babA2- and vacA s1m1/cagA+/babA2 +, with 40 % (20/50) and 28 % (14/50), respectively. In cagA +, the most frequent EPIYA motif was -ABC (78.4 %), and EPIYA-ABCC and -ABCCC motifs were found in 10.8 % of the strains. A modified EPIYT-B motif was found in 66.6 % of the sequenced strains.
Conclusion. H. pylori strains carrying vacA s1m1, cagA + and babA2 - genotypes were the most prevalent in patients with chronic gastritis from the south of Mexico. In the cagA + strains, the EPIYA-ABC motif was the most common.
Purpose. The direct rapid antibiotic susceptibility test (dRAST), based on analysing changes in bacterial micro-colonies under antibiotic conditions, detects antibiotic resistance within 6 h of direct smear examination results. This study aimed to assess the accuracy of dRAST and evaluate its potential usefulness for improving selection of appropriate antibiotic in real clinical practice settings.
Methodology. We evaluated the accuracy of dRAST by comparing the antibiotic treatments that should have been administered based on dRAST results and the broth microdilution (BMD) test and its potential usefulness via simulation.
Result. For 49/52 (94.2 %) patients with Gram-positive bacteraemia and 66/67 (98.5 %) patients with Gram-negative bacteraemia, antibiotics indicated by dRAST results were the same as those indicated by the BMD test. Among 34 patients with ineffective and suboptimal treatment, 19 (55.9 %) of patients could have received optimal treatment 1 to 2 days earlier with dRAST results. Among 33 patients given unnecessary broad-spectrum antibiotics, 1 to 2 days earlier de-escalation could have been possible for 27 (81.8 %) patients based on dRAST results.
Conclusion. The introduction of dRAST could increase the use of optimal antibiotics and reduce unnecessary broad-spectrum antibiotic use in the early period of bacteraemia.
Purpose. Micro-organisms are important triggers of peri-implant inflammation and analysing their diversity is necessary for peri-implantitis treatment. This study aimed to analyse and compare the microbiota associated with individuals with peri-implantitis, as well as clinically healthy implant sites.
Methodology. Subgingival biofilm samples were taken from 10 individuals with peri-implantitis and from at least 1 clinically healthy implant. DNA was extracted and bacterial 16S rRNA genes were amplified using universal primers. After cloning the PCR-products, amplified inserts of positive clones were digested using restriction endonucleases, and the chosen clones were sequenced. The 16S rDNA-sequences were compared to those from the public sequence databases GenBank, EMBL and DDBJ to determine the corresponding taxa.
Results. Differing distributions of taxa belonging to the phyla Firmicutes, Bacteroidetes, Fusobacteria, Actinobacteria, Proteobacteria, Synergistetes, Spirochaetae and TM 7 were detected in both the healthy implant (HI) and the peri-implantitis (PI) groups. A significantly higher relative abundance of phylum Bacteroidetes, as well as of the species Fusobacterium nucleatum, were found in the PI group (P<0.05). The putative periodontal red complex (Porphyromonas gingivalis, Tannerella forsythia) was also detected at significantly higher levels in the PI group (P<0.05), whereas the yellow group, as well as the species Veillonella dispar, tended to be associated with the HI group.
Conclusion. A shift in the healthy subgingival microbiota was shown in peri-implantitis-associated biofilm. Anaerobic Gram-negative periopathogens, including P. gingivalis and T. forsythia, seem to play an important role in peri-implantitis development and should be considered in treatment and prevention strategies.
We considered the application of MALDI-TOF mass spectrometry for BSL-3 bacterial diagnostics, with a focus on the biosafety of live-culture direct-colony testing and the stability of stored extracts. Biosafety level 2 (BSL-2) bacterial species were used as surrogates for BSL-3 high-consequence pathogens in all live-culture MALDI-TOF experiments. Viable BSL-2 bacteria were isolated from MALDI-TOF mass spectrometry target plates after ‘direct-colony’ and ‘on-plate’ extraction testing, suggesting that the matrix chemicals alone cannot be considered sufficient to inactivate bacterial culture and spores in all samples. Sampling of the instrument interior after direct-colony analysis did not recover viable organisms, suggesting that any potential risks to the laboratory technician are associated with preparation of the MALDI-TOF target plate before or after testing. Secondly, a long-term stability study (3 years) of stored MALDI-TOF extracts showed that match scores can decrease below the threshold for reliable species identification (<1.7), which has implications for proficiency test panel item storage and distribution.