Serum vancomycin levels predict the short-term adverse outcomes of peritoneal dialysis–associated peritonitis

Background: The role of monitoring serum vancomycin levels during treatment of peritoneal dialysis (PD)–associated peritonitis is controversial. Substantial inter-individual variability may result in suboptimal serum levels despite similar dosing of vancomycin. The published predictors of suboptimal serum vancomycin levels remain limited. Methods: Data were retrospectively collected from 541 patients on continuous ambulatory peritoneal dialysis between 1 January 2018 and 31 December 312019. For gram-positive cocci and culture-negative peritonitis, we adopted a vancomycin administration and monitoring protocol. Short-term adverse outcomes of PD-associated peritonitis, including transfer to haemodialysis, death, persistent infection beyond planned therapy duration and relapse, were observed. The association between trough serum vancomycin levels and short-term adverse outcomes was evaluated. Results: Intraperitoneal vancomycin was used in 61 gram-positive cocci or culture-negative peritonitis episodes in 56 patients. Fourteen episodes of short-term adverse outcomes occurred in 12 patients, whose average trough serum vancomycin levels on day 5 of treatment were significantly lower than those who didn’t experience any adverse outcomes (8.4 ± 1.7 vs 12.5 ± 4.3 mg/L, p = 0.003). In gram-positive cocci or culture-negative peritonitis patients, those with higher day 5 trough serum vancomycin levels had a lower risk of short-term adverse outcomes (odds ratio: 0.6, 95% confidence interval: 0.4 to 0.9, p = 0.011). Receiver operating charecteristic curve (ROC) analyses showed that the day 5 trough serum vancomycin levels diagnostic threshold value for short-term adverse outcomes was 10.1 mg/L. After adjustments for gender, exchange volume and residual kidney function (RKF), baseline higher peritoneal transport was associated with a suboptimal (<10.1 mg/L) day 5 serum vancomycin level. Conclusions: Serum vancomycin levels are correlated with short-term adverse outcomes of PD-associated peritonitis, and higher peritoneal solute transport status is associated with suboptimal trough serum vancomycin levels on day 5.

Peptoniphilus Colimassiliensis sp. nov. and Peptoniphilus Urinimassiliensis sp. nov., Two New Species Isolated From Humans

Strains Marseille-P3761 and Marseille-P3195 are representatives of two bacterial species isolated from human specimens. Strain Marseille-P3761 was isolated from the stool of a healthy volunteer, while strain Marseille-P3915 was cultivated from the urine of a kidney transplant recipient. Both strains are anaerobic Gram-positive cocci bacteria. Both are catalase-negative and oxidase-negative and grow optimally at 37°C in anaerobic conditions. They also metabolize carbohydrates such as galactose, glucose, fructose, and glycerol. The major fatty acids were hexadecanoic acid for both strains, Marseille-P3761 (38%) and Marseille-P3195 (31%). The highest DNA-DNA hybridization values of Marseille-P3761 and Marseille-P3195 strains when compared to their closest phylogenetic relatives were 52.3% and 56.4%, respectively. The morphological, biochemical, phenotypic and genomic characteristics strongly support that these strains are new members of the Peptoniphilus genus. Thus, we suggest that strains Marseille-P3761 (CSUR P3761 = CCUG71569) and Marseille-P3195 (CSUR P3195 = DSM 103468) are the type strains of two new Peptoniphilus species, for which we propose the names Peptoniphilus colimassiliensis sp. nov. and Peptoniphilus urinimassiliensis sp. nov., respectively.

A study of biofilm production and antimicrobial susceptibility pattern among urinary isolates

Urinary tract infection (UTI) is the most commonly acquired bacterial infection. Bacterial biofilms play an important role in urinary tract infections and are responsible for persistent infections as well as higher antimicrobial resistance. The microbial biofilms pose a public health problem as the microorganisms in the biofilms are difficult to treat with antimicrobial agents. So the present study was undertaken with the aim to study biofilm production and antimicrobial susceptibility pattern of urinary isolates. Aerobic bacterial isolates from urine samples submitted to microbiology laboratory for culture were included in the study. The isolates were tested for biofilm formation by Congo red agar method and Christensen tube method. Antimicrobial susceptibility tests were performed on these isolates by Kirby Bauer disk diffusion method as per CLSI guidelines. A total of 293 Gram negative bacilli and 59 Gram positive cocci were tested for biofilm production and antimicrobial susceptibility testing. : Gram‑negative organisms were predominant (83.24%) of all the isolates. Biofilm production was detected in 47% of the isolates. 51.7%), were the most common biofilm producing Gram negative bacilli followed by (44.32%). Amongst Gram positive cocci, (77.8%) was the most common biofilm producing organism. Biofilm producing urinary isolates displayed relatively less percentage of antimicrobial susceptibility than biofilm non producers. Biofilm forming isolates showed higher antimicrobial resistance as compared to biofilm non producer. Early detection of biofilm production in urinary isolates may aid clinicians in treatment of urinary tract infections.

TAXONOMIC COMPOSITION, MICROSCOPIC INDICES OF URINARY TRACT MICROBIOTA IN MEN WITH CALCULUS PYELONEPHRITIS

The aim of the study – to investigate the taxonomic composition, qualitativemicroecological indicators (index of constancy, frequency of occurrence, indices of speciesrichness of Margalef, species diversity of Whittaker and species dominance of Simpsonand Berger-Parker) and the immunosuppressive effect of causative agents of calculouspyelonephritis on the activity of the complement system, lysozyme and inhibition of themain immunoglobulin classes (IgM, IgA).Material and methods. Microbiological (bacteriological and mycological) urineexamination was carried out in 30 men aged 37-65 years (48.81 ± 4.27 years), patientswith calculous pyelonephritis. The ecological method was used to reveal the mechanismsof colonization of the biotope by microbiota. The adhesive properties were studied onnative human erythrocytes of group I (0I). Anti-immunoglobulin activity was studied bythe method described in the work of I.S. Gaidash, etc.Results. Out of 30 samples of the research material, 34 strains of opportunistic gramnegative and gram-positive bacteria were isolated and identifed. The majority (86.67%)had a monoculture of enterobacteria, enterococci, associations consisting of two taxonswere found in 13.33% of patients. It has been shown that 97.06% of isolated and identifedstrains from the urinary tract exhibit adhesive activity of varying degrees of activity. Onestrain of S. saprophyticus also exhibits adhesive activity (the average adhesion index is1.83 ± 0.09), which is considered as a non-adhesive strain. All strains of enterobacteriaand gram-positive cocci that persist on the mucous membrane of the urinary tract ofmen with infectious and inflammatory processes of the urinary tract with calculouspyelonephritis inhibit (P <0.05) immunoglobulins of class A (IgA).Conclusions. The infectious and inflammatory process on the mucous membranes of theurinary tract in men with calculous pyelonephritis is caused by facultative anaerobicgram-negative enterobacteria and gram-positive cocci. The presence of an infectious andinflammatory process is confrmed by an acceleration of the erythrocyte sedimentationrate by 76.67% and other clinical and laboratory studies. Pathogenicity factors arerevealed in isolated and identifed opportunistic taxons, that determine the initial stagesof the infectious and inflammatory process (cytoadhesion and colonization of the urinarytract mucosa), inhibit the functional activity of class A and M of immunoglobulins.

Real-time Screening of Foods Using Repetitive Element PCR Reveals a DNA Marker Characteristic for Enterotoxigenic Bacillus Species

Bacillus cereus is traditionally thought to be the only member of its genus accepted as a pathogen in foods like grains, fruits, vegetables, and milk due to the presence of the nonhemolytic (Nhe) operon. However, many other Bacillus spp. may also harbor the Nhe operon and be pathogenic, including not just food-associated gastrointestinal toxicoinfections, but human endophthalmitis as well. Real-time PCR targeted the nheA gene in 37 samples obtained from food, soil, and reference cultures by analyzing the standard deviations of melt peaks. Repetitive element PCR was used to compare the banding patterns of each sample against B. cereus ATCC 14579 and three B. thuringiensis strains to “fingerprint” each isolate. Of the original 43 isolated tested, 37 were Gram-positive rods. The remaining six samples were Gram-positive cocci. Twenty-five of the 37 Gram-positive Bacillus spp. were nheA positive, while twelve were negative. Many of the nheA positive strains were species not previously known to contain Nhe and were capable of causing gastroenteritis in consumers.

Gram staining v1

Gram staining is one of the first techniques used for the identification of group B Streptococcus agalactiae and one would expect to see gram-positive cocci under the microscope. The technique consists of applying a series of colorants and bleaches (acetone), which interact with the lipids of the membranes of gram-positive and gram-negative bacteria. The cell walls of gram-positive organisms retain the dye after acetone treatment and appear purple in color, whereas gram-negative organisms become discolored after acetone treatment and appear pink.

Appropriate Use of Glycopeptide Antibiotics and Therapeutic Drug Monitoring for Invasive Infections

Vancomycin and teicoplanin are representative glycopeptide antibiotics with activities against gram-positive cocci. The area under the drug concentration–time curve (AUC)/minimal inhibitory concentration (MIC) has been extensively used as an indicator of the bacteriological response to glycopeptide antibiotics, and the trough concentration has been used as a surrogate marker for the AUC/MIC. However, the guidelines for therapeutic drug monitoring (TDM) are being revised in accordance with increasing pharmacokinetic understanding of glycopeptide antibiotics. This review describes the pharmacokinetic/pharmacodynamic characteristics of glycopeptide antibiotics and discusses their optimal use with appropriate TDM.

Immunosupressive activity of opportunist pathogens of the infectious-inflammatory process in the urinary tract of men with calculous pyelonephritis

Objective - identification of pathogens of the infectious-inflammatory process of the urinary tract in men with calculous pyelonephritis, antilysozyme, anticomplementary, anti-immunoglobulin activity and inhibitory effect on the phagocytic activity of peripheral blood neutrophils.Material and methods. 34 strains of opportunistic taxa were isolated and identified by bacteriological method from 30 sick men aged 31 to 65 years (mean age 48.8 ± 4.27 years). These bacteria have antilysozyme, anti-complementary and anti-immunoglobulin activity, as well as the suppressive effect of supernatants of cultures of calculous pyelonephritis pathogens on the phagocytic activity of neutrophils in the peripheral blood of patients. The determination of the anti-complementary activity of bacteria was carried out using the principle, which includes testing the protective action of bacteria and their metabolic products against the growth of an indicator strain in the presence of a bactericidal substance (complement of blood serum). The antilysozyme activity of pathogens was investigated by a photometric method. Anti-immunoglobulin activity was studied by the method described in the work of I.S. Gaidash et al. Results. The majority of 27 (79.41%) isolated strains of Enterobacteriaceae (84%) and facultative anaerobic and aerobic gram-positive cocci (E. faecalis, S.saprophyticus) (66.67%) exhibit antilysozyme activity of varying degrees. The highest antilysozyme activity was found in the isolated strains of K. pneumoniae, 8.14% lower – in E. coli. Most (64.71%) of isolated strains of Enterobacteriaceae (68%) and gram-positive cocci (55.56%) from the urinary tract of men with calculous pyelonephritis exhibit anti-complementary activity. All isolated and identified taxa exhibit inhibitory activity against immunoglobulins of the main classes: Ig M, Ig G, and Ig A. K.pneumoniae inhibits immunoglobulins of all major classes, the concentration of Ig M decreases under the influence of this taxon by 22.36%, Ig G - by 26.88% and Ig A - by 19.61%.Conclusions. Opportunistic pathogens (E. coli, K. pneumoniae, P. mirabilis, E. cloaceae, S. marcescens, E. faecalis, S. saprophyticus) of the infectious-inflammatory process of the urinary tract in men with calculous pyelonephritis exhibit different levels of antilysozyme, anti-complementary activity; reduce the function of immunoglobulins Ig G (by 21.60%), Ig A (by 21.49%) and Ig M (by 14.30%), inhibit the phagocytic activity of neutrophilsby 15.74%, their capturing ability- by 22.59%.

Late-onset Endophthalmitis Caused by Streptococcus Cristatus after Trabeculectomy

Purpose: To report a case of late-onset bleb-associated endophthalmitis caused by streptococcus cristatus (S. cristatus) after trabeculectomy.Case summary: A 59-year-old woman presented with left ocular pain and visual disturbance. She had undergone trabeculectomy of the left eye 2 years ago. At the initial visit, she was only able to count fingers from the left eye. Whitish thin bleb, conjunctival injection, and inflammation were observed in the left anterior chamber, and the fundus could not be visualized. Despite administering topical and systemic antibiotics, the chamber reaction worsened, and hypopyon and inflammatory membrane were noticed the next day. Vitrectomy with phacoemulsification and intravitreal antibiotic injection was performed, and the intravitreal antibiotic injections were repeated over the next two days. Bacterial culture of vitreous fluid showed a growth of S. cristatus 5 days after the surgery, and inflammation improved after 7 days. One month later, she was still only able to count fingers from the left eye, but there were no signs of endophthalmitis.Conclusions: Postoperative endophthalmitis after glaucoma filtering surgeries caused by S. cristatus has not been reported previously from Korea. To the best of our knowledge, this is the first Korean case of late-onset bleb-associated endophthalmitis caused by S. cristatus. If gram-positive cocci are grown in samples from the patients with endophthalmitis after trabeculectomy, resident oral microflora such as S. cristatus should be considered as the causative pathogen.