Antibiotic Resistant Staphylococcus aureus

Staphylococcus is an adaptable pathogen and leads to rapid development of antibiotic resistance. The major targets for antibiotics are (i) the cell wall, (ii) the ribosome and (iii) nucleic acids. Resistance can either develop intrinsically or extrinsically via horizontal gene transfer, drug site modification, and efflux pumps etc. This review focuses on development of resistance to currently used antibiotics in Staphylococcal infection, novel therapeutic approaches resistance pattern of antibiotics and also the future prospectus for new antibiotics usage.

248. Outcomes of Patients with Prosthetic Septic Arthritis with Debridement and Implant Retention

Background IDSA has published guidelines for the diagnosis and management of prosthetic joint infection (PJI). However, we have observed significant variability in the interpretation and application of these guidelines with respect to the management of those with PJI following debridement and implant retention (DAIR). It is not clear if variations in antimicrobial management are affecting clinical outcomes. Methods We performed a retrospective review at an academic hospital in rural New Hampshire. We included all adult patients from 1/1/2017 to 12/31/2018 with PJI of hip or knee who underwent DAIR. The demographic data, microbiology data, antibiotics treatment and duration were collected. The primary endpoint was overall re-infection rate within 2 years of surgery. Secondary endpoint was re-infection rate stratified by organism and antimicrobial type and duration. Results A total of 26 patients were included in our study. 65% involved knee joint. 50% had late-onset infection ( >12 months). The top organisms were Streptococcus spp. (34%), CoNS (26 %) and MSSA (18 %). 15% were associated with bacteremia. Ceftriaxone was the most common antibiotic used (54 %). 38 % of patients received Rifampin PO along with IV antibiotics. All patients received PO antibiotic(s) after completing the course of IV therapy, and 7 patients were also on concomitant rifampin PO. The duration of PO antibiotic therapy was varied. 30% of patients received PO antibiotics for 6 months post IV treatment. Life-long suppression therapy were noted in 9 patients. Treatment failure within 2 years occurred in 8 patients (31%). Among those, 75% had Staphylococcal infection. All patients required hardware removal except one patient who required amputation. 2 patients developed recurrent PJI after completing 6 months and one year of PO suppression therapy, one patient had a recurrent infection while on life-long suppression. Staphylococcal infection was significantly associated with treatment failure. Conclusion Treatment of PJI with DAIR is challenging. Despite long-term IV therapy followed by oral antibiotics, there was a high rate of treatment failure (31% in our study) particularly with Staphylococcal infection. There was no association of variation of treatments and outcomes in our small cohort. Disclosures All Authors: No reported disclosures

The Changing Epidemiology and Microbiology of Patients With Prostate Abscess: Increase in Staphylococcal Infection

Background Prostatic abscesses are rare and have been most commonly associated with gram-negative bacteria; however, Staphylococcus aureus has emerged as a leading cause, particularly in persons who are immunocompromised. Methods We conducted a retrospective chart review of all patients discharged from Ben Taub Hospital with a diagnosis of prostatic abscess during January 2011–January 2019. Demographic, clinical, microbiologic, and radiographic data were abstracted from the patients’ charts and analyzed for comorbidities, causative organisms, clinical course, and outcomes. Results We identified 32 patients with a prostatic abscess during the study period. S. aureus was the most common causative organism (18/32, 56%). Most patients (24/32, 75%) were admitted to a general medicine service, and the median length of stay was 9 days. Twenty-one patients (66%) were treated with a combination of surgical drainage and antibiotic therapy; 11 (34%) were treated with antibiotics alone. All patients treated with antibiotics alone had full clinical recovery. Two patients (6.3%) died, both of whom had septic shock secondary to disseminated S. aureus infection. Conclusions Prostatic abscesses are rare and can be difficult to diagnose, leading to significant morbidity and mortality. S. aureus is a frequent causative organism especially in persons with diabetes mellitus or other immunocompromising conditions. Hematogenous spread of S. aureus infection to the prostate appears common. Prostatic abscesses can serve as the nidus of disseminated S. aureus infection.

An unusual association of disseminated staphylococcal infection in dengue fever

Dengue fever is an important mosquito-borne disease with a highly variable clinical spectrum, ranging from self-limiting mild illness to expanded dengue syndrome (EDS). While the immune-pathogenesis of dengue virus (DENV) infection had been studied thoroughly, the exact mechanism remains elusive. The transient suppression of host innate immunity by DENV might be the likely reason for dengue-associated co-infections and/or superinfections. In addition, the dual infection can worsen the clinical outcome of Dengue fever. We are reporting a case of disseminated staphylococcal infection in a 31-year-old healthy male with a recent dengue infection. Blood culture showed methicillin-sensitive Staphylococcus aureus. Selective IgM deficiency has been proved in this patient, which might explain, the occurrence of disseminated staphylococcal septicemia. This case report highlights the importance of early detection of atypical features and the emerging entity called EDS

Expression of cytokines in dairy cattle mammary gland parenchyma during chronic staphylococcal infection

The study aim was to determine the expression of genes potentially related to chronic mastitis at the mRNA and protein levels, viz. chemokine C–C motif receptor 1 (CCR1), C–C motif chemokine ligand 2 (CCL2), C–C motif chemokine ligand 5 (CXCL5), tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 18 (IL-18), in bovine mammary gland parenchyma. The study examines the differences in expression of selected genes between cows with chronic mastitis caused by coagulase-positive (CoPS) or coagulase-negative staphylococci (CoNS) and those with healthy udders (H). Samples were collected from the udder quarters from 40 Polish Holstein–Friesian cows; 54 of these samples were chosen for analysis based on microbiological analysis of milk taken two days before slaughter. They were categorized into three groups: CoPS (N = 27), CoNS (N = 14) and H (N = 13). The RNA expression was analyzed by RT-qPCR and protein concentration by ELISA. No differences in the mRNA levels of seven genes (TNFα, IL-18, CCR1, IL-1β, CCL2, IL-8, IL-6) and four proteins (TNFα, IL-18, CCR1, IL-1β) were identified between the CoPS and H groups. Higher transcript levels of CXCL5 (p ≤ 0.05) gene were noted in CoPS than in H. Compared to H, higher concentrations of IL-8 and CXCL5 (p ≤ 0.05) were observed in CoPS (0.05 < p < 0.1) and CCL2 (0.05 < p < 0.1) in CoNS, while lower levels of Il-6 were found in CoPS. This may suggest that during chronic mastitis the organism stops producing pro-inflammatory cytokines, probably to protect the host tissues against their damage during prolonged infection.

Outcomes of Pediatric Patients With Sepsis Related to Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus Infections Requiring Extracorporeal Life Support: An ELSO Database Study

Background: Extracorporeal membrane oxygenation (ECMO) is increasingly utilized for pediatric sepsis unresponsive to steroids and inotropic support. Outcomes of children with sepsis are influenced by the type of pathogen causing their illness.Objective: To determine if the outcomes of children with Staphylococcus aureus sepsis receiving ECMO differed according to microbial sensitivity (Methicillin-resistant Staphylococcus aureus [MRSA] vs. Methicillin-sensitive Staphylococcus aureus [MSSA]).Methods: Retrospective case-matched cohort study of children (0–&lt;18 years) with Staphylococcus aureus sepsis reported to the ELSO registry from more than 995 centers. Inclusion criteria were age 0–18 years, laboratory diagnosis of Staphylococcal infection, clinical diagnosis of sepsis, and ECMO deployment. Exclusion criteria were no laboratory diagnosis of Staphylococcal infection. We compared patient demographics, pre-ECMO management and outcomes of those with MRSA vs. MSSA using Chi-Square test, with independent samples t-test used to test to compare continuous variables.Results: In our study cohort of 308 patients, 160 (52%) had MSSA and 148 (48%) MRSA with an overall survival rate of 41.5%. There were no differences in the age group (p = 0.76), gender distribution (p = 0.1) or racial distribution (p = 0.58) between the two groups. P value for racial distribution should be 0.058. There were 91 (56.8%) deaths in the MSSA group and 89 (60.1%) deaths (p = 0.56) in the MRSA group. Duration on ECMO (p = 0.085) and the time from intubation to ECMO (p = 0.37) were also similar in the two groups. Survival with MSSA sepsis and MRSA sepsis did not improve significantly over the 20 years evaluated despite an increase in ECMO utilization.Conclusion: In this multi-center retrospective study, there were no differences in outcomes for children receiving ECMO support with Staphylococcus aureus sepsis according to microbial methicillin sensitivity. There was no significant increase in survival among patients with MRSA and MSSA infections receiving ECMO in the last 20 years.

Results of treatment of primary staphylococcal enterocolitis in infants with the use of antibacterial drugs and their combination with bacteriophages: a prospective study

In infectious pathology in infants, staphylococcal infection occupies a leading place, is characterized by the rapid development of intoxication, a purulent-destructive process with the possibility of generalization of infection, affecting the course and outcome of the disease.The aim of the study was to study the results of treatment of primary staphylococcal enterocolitis, in infants, with the use of antibacterial drugs and their combination with bacteriophages.Research methods. The frequency of elimination of staphylococcus, the duration of the main symptoms (fever, diarrhea, toxicosis with exicosis) as a result of treatment of primary staphylococcal enterocolitis (confirmed by laboratory) were analyzed in children aged from 1 to 12 months who received inpatient antibacterial drugs (nifuroxazide, azithromycin) or their combination with bacteriophages (staphylococcal, pyobacteriophage). The data accounting period is from January 2017 to December 2020.The results of the study. The results of treatment of staphylococcal enterocolitis were studied in 4 groups: monotherapy with nifuroxazide (n = 39) or azithromycin (n = 40), a combination of nifroxazide+staphylococcal bacteriophage (n = 41) or azithromycin + piobacteriphage (n = 38). The groups were comparable by gender, age, and clinical manifestations of the disease. Elimination of staphylococcus on the 10th—12th day. treatment with monotherapy with antibacterial drugs was achieved in 31—35%, with their combination with bacteriophages — in 51—64% of patients in each combination (df = 3, p < 0.05). Against the background of combined therapy, the symptoms of the disease (diarrhea, vomiting) were stopped 1.2 times faster; the number of patients with lactase deficiency and intestinal dysbiosis decreased by 1.7—2 times, with monotherapy with antibacterial drugs-by 1.3—1.4 times (df = 3, p < 0.05).Conclusion. Treatment of primary staphylococcal enterocolitis in children, including antibacterial drugs and bacteriophages, is more effective than monotherapy with antibacterial drugs.

IMPACT OF HYPOXIA AND INFECTION ON THE MORPHOLOGY OF THETHYROID GLAND

The investigation aimed to study the microscopic features of the thyroid gland under the influence of barochamber hypoxia and staphylococcal infection in the experiment. Materials and methods of the study. During the study 30 healthy adult male white rats weighing 180–200 g were used. Morphological features of the gland were studied by histological methods. Results of the study. Analysis of the study results shows that morphological changes occurring in the thyroid gland cells are more pronounced in animals of the infectious group than in animals of the hypoxia group. Thus, under the influence of infection, atrophic changes prevail in the gland tissue, and under the influence of hypoxia, hyperplasia, and hypertrophy, proliferation and differentiation of gland cells are observed. This can be considered a structural reconstruction of the gland tissue and its adaptation to new conditions.

STUDY OF INDICATORS OF ANTIMICROBIAL RESISTANCE IN PATIENTS WITH ALLERGODERMATOSIS, СОMPLICATED BY STAPHYLOCOCCUS INFECTION, ACCORDING TO THE RESULTS OF TESTS WITH AUTOSTRAINS

The relevance of the study is due to the lack of data on the state of nonspecific cellular immunity in studies with sera and autostrains of S. aureus isolated from patients with allergic dermatoses, which would reflect the intensity of antimicrobial immunity in patients with allergic dermatoses, aggravated by staphylococcal infection, depending on the severity of dermatosis. The aim of the study was to determine and analyze the results of antimicrobial immunity indicators in patients with atopic dermatitis and true eczema, aggravated by staphylococcal infection, using sera and autostrains of S. aureus, depending on the severity of the disease. Material and methods. It was included 107 patients with different stage of the allergic dermatoses severity and control group of 15 healthy individuals to the research . The patients were divided into 3 groups in according to the severity of cutaneous process course. There were determined the basic indices of initial stages of phagocytosis and oxydepending bactericidal activity of the phagocytes. It was conducted the immunologic examinations using the autostrains patient from the locus morbi and standard strain S. aureus ATCC for the estimation of antimicrobial immunity. Results. Evaluation of phagocytosis indices in patients with allergodermatosеs showed a correlation between the severity of the disease course and the level of inhibition of the cellular level of nonspecific immunity. According to the results of studies using autostrains S. aureus, the most significant inhibition of phagocytosis (p ≤ 0,05), compared to the values of similar indicators in the control group of healthy individuals, it was found in the groups of patients with moderate and severe atopic dermatosis (AD) course, respectively: phagocytic activity (PhА) (78,1 ± 1,4) and (72,4 ± 1,4) and (71,7 ± 0,8) %; phagocytic number___ (PhN) (5,3 ± 0,2) and (4,3 ± 0,2) and (3,5 ± 0,1) absolute number (abs. num.); phagocytic index__ (PhI) (6,8 ± 0,2) and (6,2 ± 0,2) and (4,8 ± 0,1) abs. num.; phagocytic capacity (PhC) (30,3 ± 1,0) and (26,5 ± 1,8) and (22,6 ± 0,8) ×103 microbial cell /mm3; spontaneous test of the renovation of nitroblue tetrazolium (sNBT) (42,1 ± 1,3) and (48,1 ± 1,2) and (50,6 ± 0,3) %; induction test of the renovation of nitroblue tetrazolium (іNBT) (63,4 ± 1,6) and (53,4 ± 0,8) and (51,7 ± 0,7) %. In the patients with true eczema (TE), they revealed a similar regularity of phagocytosis inhibition, most pronounced in patients with a severe disease course (p ≤ 0,05), but with a slightly smaller degree of difference between the indicator values of phagocytosis compared with the group of healthy individuals, respectively: PhА (74,8 ± 1,3) and (78,1 ± 1,4) %; PhN (4,5 ± 0,1) and (5,3 ± 0,2) abs. num.; PhI (5,9 ± 0,2) and (6,8 ± 0,9) abs. num.; sНСТ (46,0 ± 0,6) and (42,1 ± 1,3) %; іНСТ (51,8 ± 0,8) and (63,4 ± 1,6) %. Conclusions. The results of identification of phagocytosis in patients with allergodermatosеs using the standard culture of S. aureus ATCC 25923 generally reflect the described regularities of inhibition in patients of the cellular level of nonspecific immunity, but are less presentable for their identification in comparison with the autostrains. Keywords: allergic dermatoses, severity of the course, S aureus autostrains, S. aureus ATCC 25923, antimicrobial resistance.