Staphylococcal Species Research Articles

Isolation and Identification of Staphylococcus Species from Cottage Cheese and Yoghurt in Selected Districts of East Wollega Zone, Ethiopia

A cross-sectional study was conducted to isolate and identify staphylococcus species from cottage cheese and yogurt in selected district of east Wollega zone, Ethiopia, from April 2017 to December 2017. A total of 188 milk product (62 cheeses and 126 yogurts) were collected from study areas. Of the total 188 milk product examined 69(36.7%) were positive for staphylococcus species. The result indicated that 25(13.3%) cottage cheese and 44(23.4%) yogurt samples were contaminated with staphylococcus species. The S. aureus was the most frequently isolated species among different samples accounting for 44(23.4%), followed by S. intermedius 11(5.9%), CNS 8(4.3%) and S. hyicus 6(3.2%). Prevalence of Staphylococcus were significantly higher (p<0.05) in plastics containers 76(40.4%) than others storage materials of milk product. This study revealed that, the prevalence of Staphylococcus species has statistically significant difference (P=0.002) among study districts of the area. The distribution of prevalent Staphylococci over different geographical area is indicators for lack of proper personal, environmental hygiene and sanitation; and absence of difference in animal husbandry practice in all study area. Hence, implementing strict hygienic control measures is important in order to guarantee the quality of cattle derivative food products.

Bats Are Carriers of Antimicrobial-Resistant Staphylococcaceae in Their Skin

Bats have emerged as potential carriers of zoonotic viruses and bacteria, including antimicrobial-resistant bacteria. Staphylococcaceae has been isolated from their gut and nasopharynx, but there is little information about Staphylococcaceae on bat skin. Therefore, this study aimed to decipher the Staphylococci species in bat skin and their antimicrobial susceptibility profile. One hundred and forty-seven skin swabs were collected from bats during the spring and summer of 2021 and 2022. Bats were captured in different areas of the Metropolitan Region of São Paulo, Brazil, according to the degree of anthropization: Area 1 (Forested), Area 2 (Rural), Area 3 (Residential-A), Area 4 (Slum-- up to two floors), Area 5 (Residential-B-condo buildings), and Area 6 (Industrial). Swabs were kept in peptone water broth at 37 °C for 12 h when bacterial growth was streaked in Mannitol salt agar and incubated at 37 °C for 24 h. The disc-diffusion test evaluated antimicrobial susceptibility. Staphylococcaceae were isolated from 42.8% of bats, mostly from young, from the rural area, and during summer. M. sciuri was the most frequent species; S. aureus was also isolated. About 95% of isolates were resistant to at least one drug, and most strains were penicillin resistant. Eight isolates were methicillin resistant, and the mecA gene was detected in one isolate (S. haemolyticus). Antimicrobial resistance is a One Health issue that is not evaluated enough in bats. The results indicate that bats are carriers of clinically meaningful S. aureus and antimicrobial-resistant bacteria. Finally, the results suggest that we should intensify action plans to control the spread of resistant bacteria.

Effect of Staphylococcus aureus on the Keratinocytes in Atopic Dermatitis

Atopic dermatitis (AD) is associated with Staphylococcus aureus skin colonization. S. aureus strains secrete proteins, virulence factors and enterotoxins that may affect immune function and skin integrity. We sought to investigate how specific Staphylococcal species and strains affect epithelial barrier function.

SILVER-COATED MEGAPROSTHESES IN RECONSTRUCTION FOR ORTHOPAEDIC ONCOLOGY AND BONE LOSS

Rates of prosthetic joint infection in megaprostheses are high. The application of silver ion coating to implants serves as a deterrent to infection and biofilm formation.A retrospective review was performed of all silver-coated MUTARS endoprosthetic reconstructions (SC-EPR) by a single Orthopaedic Oncology Surgeon. We examined the rate of component revision due to infection and the rate of infection successfully treated with antibiotic therapy. We reviewed overall revision rates, sub-categorised into the Henderson groupings for endoprosthesis modes of failure (Type 1 soft tissue failure, Type 2 aseptic loosening, Type 3 Structural failure, Type 4 Infection, Type 5 tumour progression).283 silver-coated MUTARS endoprosthetic reconstructions were performed for 229 patients from October 2012 to July 2022. The average age at time of surgery was 58.9 years and 53% of our cohort were males. 154 (71.3%) patients underwent SC-EPR for oncological reconstruction and 32 (14.8%) for reconstruction for bone loss following prosthetic joint infection(s). Proximal femur SC-EPR (82) and distal femur (90) were the most common procedures. This cohort had an overall revision rate of 21.2% (60/283 cases). Component revisions were most commonly due to Type 4 infection (19 cases), Type 2 aseptic loosening/culture negative disease (15 cases), and Type 1 dislocation/soft tissue (12 cases).Component revision rate for infection was 6.7% (19 cases). 15 underwent exchange of implants and 4 underwent transfemoral amputation due to recalcitrant infection and failure of soft tissue coverage. This equates to a limb salvage rate of 98.3%. The most common causative organisms remain staphylococcus species (47%) and polymicrobial infections (40%).We expand on the existing literature advocating for the use of silver-coated endoprosthetic reconstructions. We provide insights from the vast experience of a single surgeon when addressing patients with oncological and bone loss-related complex reconstruction problems.

Microbial dynamics, risk assessment and sensory evaluation of metata ayib (traditional spiced fermented cottage cheese)

Introduction: Different traditional fermented foods and beverages made from various components are available in Ethiopia. Metata ayib, a traditional fermented dairy product, is created by blending ayib (Ethiopian cottage cheese) with different spices in a tightly covered container. Therefore, metata ayib is a ready-to-eat food. If it is handled with poor hygiene standards or is contaminated with potentially hazardous microorganisms, consuming it could be harmful. Therefore, the goal of this study was to assess the microbiological dynamics, organoleptic properties, and growth potential of some foodborne pathogens in metata ayib. Methods: Three different kinds of metata ayib were made in a laboratory, and, using conventional microbiological methods, a microbiological examination was carried out during the fermentation process. Using 10 panellists, the sensory evaluation of the different types of metata ayib was conducted. The growth potential of selected pathogenic microorganisms on the preferred ready-to-eat metata ayib was then tested. Results: Coliforms and Staphylococci species were not found in any type of metata ayib during the fermentation process. The counts of aerobic mesophilic bacteria (AMBC), lactic acid bacteria (LABC), yeast and mold (YMC) in metata ayib that was made with black mustard seed and 12 other common spices were highest. Metata ayib prepared with black mustard seed and 12 additional common spices had significantly (P<0.05) higher sensory qualities in terms of taste than metata ayib prepared with red pepper or Ethiopian mustard seed, and 12 additional common spices. The growth capacity of Candida albicans in metata ayib made with black mustard seed and 12 other common spices showed greater resistance (24 h) than both E. coli (18 h) and S. aureus (6 h). Conclusions: Care should be taken when handling fermented metata ayib. To improve the safety and health benefits of fermented metata ayib, it is preferable to inoculate it with possible probiotics.

Staphylococcus lugdunensis and coagulase-negative staphylococci species characterisation in a tropical climate

Staphylococcus lugdunensis and coagulase-negative staphylococci species characterisation in a tropical climate

Evolution of the Prevalence of Antibiotic Resistance to Staphylococcus spp. Isolated from Horses in Florida over a 10-Year Period.

Previous studies documented antibiotic resistance in horses but did not focus on skin specifically. We investigated antibiotic resistance and correlations between resistance patterns in skin infections. Records from 2009 to 2019 were searched for Staphylococcal infection and susceptibility results. Seventy-seven cases were included. Organisms identified were S. aureus (48/77), S. pseudintermedius (7/77), non-hemolytic Staphylococcus (8/77), beta-hemolytic Staphylococcus (6/77), and other species (8/77). Samples included pyoderma (36/77), wounds (10/77), abscesses (15/77), incision sites (5/77), nose (8/77), and foot (3/77). A trend analysis using non-parametric Spearman's test showed significant upward trend of resistance (p < 0.05) for 3/15 antibiotics (ampicillin, cefazolin, penicillin). Susceptibility was significantly different by Staphylococcal species for 8/15 antibiotics. Gentamicin showed significant susceptibility differences based on source (all abscesses were susceptible to gentamicin). Steel-Dwass test showed statistically significant (p = 0.003) difference between incision sites and abscesses. A non-parametric Kendall's T-test found significantly negative correlation between cefazolin and amikacin sensitivity (p = 0.0108) and multiple positive correlations of resistance (p < 0.05). This study confirms increasing resistance in dermatologic samples. It is unlikely that the sample source affects resistance, but Staphylococcus species may affect it. Study limitations include lack of information about previous antibiotic use and small sample size.

Hydrogel Formulations of Antibacterial Pyrazoles Using a Synthesized Polystyrene-Based Cationic Resin as a Gelling Agent.

Here, to develop new topical antibacterial formulations to treat staphylococcal infections, two pyrazoles (3c and 4b) previously reported as antibacterial agents, especially against staphylococci, were formulated as hydrogels (R1-HG-3c and R1HG-4b) using a cationic polystyrene-based resin (R1) and here synthetized and characterized as gelling agents. Thanks to the high hydrophilicity, high-level porosity, and excellent swelling capabilities of R1, R1HG-3c and R1HG-4b were achieved with an equilibrium degree of swelling (EDS) of 765% (R1HG-3c) and 675% (R1HG-4b) and equilibrium water content (EWC) of 88% and 87%, respectively. The chemical structure of soaked and dried gels was investigated by PCA-assisted attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy, while their morphology was investigated by optical microscopy. Weight loss studies were carried out with R1HG-3c and R1HG-4b to investigate their water release profiles and the related kinetics, while their stability was evaluated over time both by monitoring their inversion properties to detect possible impairments of the 3D network and by PCA-assisted ATR-FTIR spectroscopy to detect possible structural changes. The flow and dynamic rheological characterization of the gels was assessed by determining their viscosity vs. shear rate, applying the Cross rheological equation to achieve the curves of shear stress vs. shear rate, and carrying out amplitude and frequency sweep experiments. Finally, their content in NH3+ groups was determined by potentiometric titrations. Due to their favorable physicochemical characteristic and the antibacterial effects of 3c and 4b possibly improved by the cationic R1, the pyrazole-enriched gels reported here could represent new weapons to treat severe skin and wound infections sustained by MDR bacteria of staphylococcal species.

Prevention of Surgical Site Infection Following Open Spine Surgery: The Efficacy of Intraoperative Wound Irrigation with Normal Saline Containing Gentamicin Versus Dilute Povidone-Iodine

Intraoperative wound irrigation (IOWI) is an important step in preventing surgical site infection (SSI). This study compared the effectiveness of saline with gentamicin versus povidine-iodine (PI) as IOWI solutions in preventing SSI in open spine surgery. It is a prospective comparative study. Patients who had noninstrumented open spine surgery were randomized into 2 groups. Group A and B patients had their surgical wounds irrigated with saline containing gentamicin solution and dilute PI solution, respectively. Both groups were assessed for the occurrence of SSI. A total of 80 patients, divided into 2 groups of 40 each completed the study. Overall, the SSI rate was 17.5% for patients in the normal saline containing gentamicin group (A) and 2.5% for those in the dilute PI group (B), this difference was statistically significant (P= 0.025). The cervical and thoracic spine regions have the same SSI rate (7.1% and 0%, respectively) in both groups. However, in the lumbosacral region, the SSI rate was 31.6% in A and 0% in B, this was statistically significant (P= 0.006). The isolated organisms in patients with SSI were staphylococcus species (42.86% of SSI in A and 0% in B) and pseudomonas species (42.86% of SSI in group A and 100% in group B), and this difference was profound in the lumbosacral spine region (P= 0.008). IOWI with 3.5% dilute PI solution is more efficacious in preventing SSI and has wider microbial coverage compared to normal saline containing gentamicin solution as IOWI fluid in noninstrumented open spine surgery.

Detection and characterization of potential virulence determinants in Staphylococcus pseudintermedius and S. schleiferi strains isolated from canine otitis externa in Korea.

A recent increase in the occurrence of canine skin and soft tissue infections, including otitis externa and pyoderma, caused by antimicrobial-resistant Staphylococcus pseudintermedius and S. schleiferi has become a significant public and veterinary health issues. We investigated the virulence potentials associated with the occurrence of canine otitis externa in S. pseudintermedius and S. schleiferi. In this study, the prevalence of genes encoding leukocidins, exfoliative toxins, and staphylococcal enterotoxins (SEs) was investigated using previously characterized S. pseudintermedius (n = 26) and S. schleiferi (n = 19) isolates derived from canine otitis externa. Susceptibility to cathelicidins (K9CATH and PMAP-36) and hydrogen peroxide (H2O2) was also examined in both staphylococcal species. A high prevalence of genes encoding leukocidins (lukS/F-I, lukS1/F1-S, and lukS2/F2-S), exfoliative toxins (siet, expB, and sset), and SEs was identified in both S. pseudintermedius and S. schleiferi isolates. Notably, S. pseudintermedius isolates possessed higher number of SE genes, especially newer SE genes, than S. schleiferi isolates harboring egc clusters. Although no significant differences in susceptibility to K9CATH and H2O2 were observed between the two isolate groups, S. pseudintermedius isolates exhibited enhanced resistance to PMAP-36 compared to S. schleiferi isolates. These findings suggest that high a prevalence of various toxin genes together with enhanced resistance to cathelicidins may contribute to the pathogenicity of S. pseudintermedius and S. schleiferi in canine cutaneous infections.

Antimicrobial profile of coagulase-negative staphylococcus isolates from categories of individuals at a neonatal intensive care unit of a tertiary hospital, Ghana.

we compared the antimicrobial resistance profile of young infants' clinical isolates (from blood samples) of Staphylococcus epidermidis and haemolyticus with those colonizing mothers, clinical staff, and students. Also, screened for resistance to the watch and reserve classified groups, antibiotics not prescribed in the Ho Teaching Hospital (HTH), Ghana. a cross-sectional study was conducted from March to June 2018 to determine the antimicrobial susceptibility of twenty-one antimicrobials for 123 isolates consisting of 54 S. epidermidis and 69 S. haemolyticus cultured from the participants. VITEK 2 was used for antimicrobial susceptibility testing. Staphylococcal species were identified using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF). Statistical analysis was done with Grad-Pad prism. for S. epidermidis, clinical staff isolates have the highest methicillin-resistant (65%), followed by young infants' (50%) and mothers' and students' twenty-five percent each. Both young infants and clinical staff's Staphylococcus haemolyticus isolates have 100% methicillin-resistant, while mothers' and students' ones have 82% and 63%, respectively. We have identified resistance to one watch (teicoplanin), two reserves (tigecycline and fosfomycin) antimicrobial groups, and mupirocin, an unclassified group. identifying coagulase-negative staphylococci (CoNS) resistance to watch and reserve groups of antimicrobials in a non-previously exposed hospital calls for further studies to determine molecular mechanisms of resistance to these antimicrobials.

Bacteriological Profile and Antibiotic Susceptibility Patterns of Sepsis-Causing Bacteria at the Neonatal Intensive Care Unit of a Tertiary Health Care Facility in Ghana

Background: Neonatal sepsis is a clinical emergency that requires sound evaluation supported by accurate laboratory analysis and timely clinical intervention for its management. This study, therefore, was conducted to identify bacteria causing neonatal sepsis and their susceptibility to the commonly prescribed antibiotic at the Neonatal Intensive Care Unit of a tertiary health care facility in the Northern Region of Ghana. Methods: Neonatal biodata were collected from patient folders, after which identification, isolation, and susceptibility of isolated bacteria to prescribed anti-bacterial (Kirby-Bauer disk diffusion method) were carried out on single venipuncture blood samples aseptically drawn from 275 neonates clinically diagnosed with sepsis. Results: 275 neonates took part in the study, of which 218 (79.3%) presented with early-onset sepsis (EOS) and 57 (20.7%) with late-onset sepsis (LOS). The laboratory results confirmed a septicemia prevalence of 70.3% among neonates clinically diagnosed with sepsis. Preterm delivery ( P = .01), hypothermia ( P = .001), and delivery at the tertiary healthcare facility were significantly associated with EOS ( P &lt; .000), while low birth weight ( P = .012), duration of hospital stay ( P = .001), and delivery at the tertiary healthcare facility ( P &lt; .000) were found to be significantly associated with LOS. Gram-positive cocci constituted 54.9% (107), with Gram-negative constituting 45.1% (88) of all the bacteria isolates. Coagulase-negative staphylococcus (CoNS) 70.1% (75) and Klebsiella species 39.8% (35) were the dominant Gram-positive and Gram-negative isolates, respectively. 57.8% and 55.8% of CoNS isolates were susceptible to ampicillin and amoxicillin/clavulanic acid, respectively. 93.5% of CoNS and all the isolated Staphylococcus aureus and Klebsiella species were susceptible to amikacin. Conclusions: Coagulase-negative staphylococcus (CoNS) and Klebsiella species were the predominant Gram-positive and negative sepsis-causing agents at the NICU, respectively. Amikacin exhibited the highest sensitivity to Gram-positive and negative causative agents, making it a strong candidate for consideration in the facility’s empirical treatment of neonatal sepsis.

Incidence of Staphylococcus Aureus in Lower Respiratory Tract Infections: An Emerging Trend

Introduction: The pathogen like staphylococcus spp. associated with multidrug resistance is one of the major concerns. Prompt diagnosis of staphylococcal Lower Respiratory Tract Infection (LRTI) with its antibiogram plays a vital role in better outcomes of treatment and reducing the cost of hospital stay of patients. Aim: To find out incidence of staphylococcal LRTIs. Materials and Methods: This prosprective cross-sectional study was conducted in the Department of Microbiology, SMBT Institute of Medical Sciences and Research Centre, Nashik, Maharashtra, India. The duration of the study was 23 months, from June 2017 to May 2019. The specimens were screened for staphylococcal species as per the standard bacteriological procedure. The gram-positive, catalase-positive isolates were further subjected to detection of antimicrobial susceptibility patterns as per Clinical and Laboratory Standards Institute (CLSI) guidelines. The data was analysed by using Statistical Package for Social Sciences (SPPS) version 20.0. Results: The majority of the patients were of old age groups and the average mean age was 57.95±6.18 years. A total of 22/421 Staphylococcus aureus (S. aureus) were isolated from the patients suffering from LRTIs. High incidence was noted in male patients 21/22 (95.5%) than in females 1/22 (4.5%) and 100% of patients were hospitalised with a complaint of LRTIs. The majority of strains were isolated from sputum sample 18/22 (81.8%), followed by 3/22 (13.6%) from pleural aspiration, and 1/22 (4.5%) from endotracheal secretion. Almost 18/22 (81.8%) patients were of pneumonia, followed by 3/22 (13.6%) were of empyema and 1/22 (4.5%) were of sinusitis. All the isolates were sensitive to linezolid, vancomycin, and ceftaroline. Conclusion: In the present study, LRTI associated with S. aureus was found to be (5.22%). It was also observed that, all strains were sensitive to vancomycin, linezolid, and ceftaroline which is unique. Hence, the staphylococcal infection can be treated with low cost and hospital stay if diagnosed in time by microbiological profile, as the clinical presentation and susceptibility to antimicrobial agents vary in different geographical areas.

Clinical and Subclinical Mastitis in Ruminants: A Review of Etiological agents, Diagnosis, Clinical Management and Risk factors

Ruminant mastitis is a welfare and economic problem of livestock and the dairy industry. It is a major animal health problem in countries where livestock are raised for the purpose of milk production. This Review focuses on ruminant mastitis, etiologic agents, diagnostic test and associated risk factors. In this narrative review, a comprehensive literature search of all relevant articles was performed to identify articles published in Science Direct, Web of Science, PubMed, Scopus, MEDLINE, Google Scholar, LISTA and AJOL. English articles published from 2010 to 2023 were reviewed and used. The findings revealed that even though Staphylococcus aureus, Non-aureus Staphylococci species, and Streptococci are the major mastitis pathogens. Others like Escherichia coil, Klebsiella, Citrobacter, Enterobacter, Pseudomonas, Proteus, Serratia, Bacillus, and Corynebacterium etc were isolated from milk samples. Diagnosis was observed to be based on observation of milk and cardinal signs of inflammation of the mammary glands, the use of diagnostic test, like bacterial culture, Strip cup test, White side test (WST), Surf field mastitis test (SFMT), and California Mastitis test (CMT). Molecular typing techniques including PCR, Sequencing, MALDI-TOF MS, MLST, PFGE, spa typing etc have also been observed important role in characterizing agents of mastitis. Major risk factor observed is age, parity and stage of lactations. Clinical management of this condition in ruminants is based on the understanding of the etiology, and treatment options.

Bacterial infection of the urinary tract and glucose level in patients presented with urinary tract infection in tertiary care hospital, Bihar

Objectives: This study was to evaluate the bacterial Infection of the Urinary Tract and Glucose Level in patients presented with Urinary Tract Infection in tertiary care hospital. Methods: Sterilized universal (glass) containers were used in collecting early morning midstream urine from patients. Subjects were instructed to void 5mls of Mid-Stream urine. Two hundred early morning, mid-stream urine samples was collected from one hundred patients of urinary tract infection, age between 1 to &gt;60 years with the presence of bacterial species and 2mls of blood was obtained for glucose screening (glycosuria). Testing for Glucose, macroscopic Examinations, and gram stain procedures were performed to all blood samples. Results: Most of the patients 46(23%) were in age group of 51-60 years. 43(21.5%), 39(19.5%) and 35(17.5%) patients were in age group of 21-30 years, 41-50 years and 31-40 years respectively. most predominant isolated bacteria causing urinary tract infection were Escherichia coli 27(32.53%). Other isolated microorganisms were staphylococcus species 18(21.67%), streptococcus species 18(21.67%), 16(19.27%) Klebsiella species and 2(2.41%) proteus spp, pseudomonas spp. Prevalence of UTI was higher in females 49(59.04%) than males 34(40.96%). out of 200 samples, 83(41.5%) samples were infected. Among them, 24(28.92%) had both bacterial infection with glucose.

Phenotypic and Genomic Insights into Biofilm Formation in Antibiotic-Resistant Clinical Coagulase-Negative Staphylococcus Species from South Africa.

The work aims to investigate biofilm formation and biofilm/adhesion-encoding genes in coagulase-negative staphylococci (CoNS) species recovered from blood culture isolates. Eighty-nine clinical CoNS were confirmed using the VITEK 2 system, and antibiotic susceptibility testing of isolates was conducted using the Kirby-Bauer disk diffusion method against a panel of 20 antibiotics. Isolates were qualitatively screened using the Congo red agar medium. Quantitative assays were performed on microtiter plates, where the absorbances of the solubilised biofilms were recorded as optical densities and quantified. In all, 12.4% of the isolates were strong biofilm formers, 68.5% had moderate biofilm capacity, and 17.9% showed weak capacity. A subset of 18 isolates, mainly methicillin-resistant S. epidermidis, were investigated for adherence-related genes using whole-genome sequencing and bioinformatics analysis. The highest antibiotic resistance rates for strongly adherent isolates were observed against penicillin (100%) and cefoxitin (81.8%), but the isolates showed no resistance to linezolid (0.0%) and tigecycline (0.0%). The icaABC genes involved in biofilm formation were detected in 50% of the screened isolates. Other adherence-related genes, including autolysin gene atl (88.8%), elastin binding protein gene ebp (94.4%), cell wall-associated fibronectin-binding protein gene ebh (66.7%), clumping factor A gene clfA (5.5%), and pili gene ebpC (22.2%) were also found. The insertion sequence IS256, involved in biofilm formation, was found in 10/18 (55.5%) screened isolates. We demonstrate a high prevalence of biofilm-forming coagulase-negative staphylococci associated with various resistance phenotypes and a substantial agreement between the possession of biofilm-associated genes and the biofilm phenotype.

A Thermosensitive, Chitosan-Based Hydrogel as Delivery System for Antibacterial Liposomes to Surgical Site Infections.

Prophylaxis and the treatment of surgical site infections (SSIs) with antibiotics frequently fail due to the antibiotic resistance of bacteria and the ability of bacteria to reside in biofilms (i.e., bacterial clusters in a protective matrix). Therefore, alternative antibacterial treatments are required to combat biofilm infections. The combination of diethyldithiocarbamate (DDC-) and copper ions (Cu2+) exhibited antibiofilm activity against the staphylococci species associated with SSIs; however, the formation of a water-insoluble Cu(DDC)2 complex limits its application to SSIs. Here, we describe the development and antibiofilm activity of an injectable gel containing a liposomal formulation of Cu(DDC)2 and Cu2+ (lipogel). Lyophilized liposomes were incorporated into a mixture of chitosan (CS) and beta-glycerophosphate (βGP), and the thermosensitive gelling properties of CS-βGP and the lipogel were determined. The liposomes remained stable after lyophilization over six months at 4-6 °C and -20 °C. The sol-gel transition of the gel and lipogel occurred between 33 and 39 °C, independently of sterilization or storage at -20 °C. CS-βGP is biocompatible and the liposomes were released over time. The lipogel prevented biofilm formation over 2 days and killed 98.7% of the methicillin-resistant Staphylococcus aureus and 99.9% of the Staphylococcus epidermidis biofilms. Therefore, the lipogel is a promising new prophylaxis and treatment strategy for local application to SSIs.

912. Impact of Rapid Identification and Stewardship Intervention on Coagulase-negative Staphylococcus Bloodstream Infection (BSI)

Abstract Background Coagulase-negative staphylococci (CoNS) are commonly isolated from blood cultures (BCx). Most do not require treatment (tx), yet antibiotics are frequently initiated. Workup of CoNS BSI consumes significant resources. We aimed to demonstrate the safety and efficacy of an early algorithm-based rapid diagnostic testing (RDT) plus antimicrobial stewardship (ASP) intervention. Methods BCx with CoNS were captured in 3 time periods to represent pre-RDT, RDT-only, and RDT+ASP. GenMark ePlex RDT was implemented for all Gram-positive BCx, identifying S. epidermidis and other non-aureus/lugdunensis Staphylococcal species. Results were called to ASP in both RDT-only and RDT+ASP periods. In the latter, a prospective algorithm was implemented to standardize ASP recommendations (Fig 1) for cases classified as simple, uncomplicated, and complicated BSI. The primary outcome was receipt of &amp;lt; 24h of antibiotic tx. Safety outcomes included rates of recurrent BSI and hospital readmission. Results 184 patients were included (Fig 2). The median age was 62, 54% were male, and the median Charlson comorbidity index was 5. 41% had a central venous catheter at time of BSI. Overall, 67%, 19%, and 12% of cases were classified as simple, uncomplicated, or complicated BSI, respectively (Fig 3). BSI class and patient demographics did not vary between periods. During pre- and post-RDT periods, median days of antibiotic tx did not vary significantly for patients with simple BSI (1.1 vs 1.2). In contrast, median days of tx were reduced to 0 (P=0.005) for simple BSI in the RDT+ASP period. Overall, 54% of patients with CoNS BSI received &amp;lt; 24h of tx in RDT+ASP time period compared to 34% (P=0.009) in the combined pre-RDT and RDT-only periods. Tx was entirely avoided in 28% of CoNS BSI cases in the RDT+ASP period compared to 16.5% of cases in other periods (P=0.07). 7 cases classified as simple were reclassified as uncomplicated or complicated after further work up. Rates of recurrent BSI and 30-day readmission were comparable across time periods. Conclusion Our algorithm-based ASP + RDT intervention reduced antibiotic tx for CoNS BSI, an effect not realized with RDT alone. These data attest to the safety and efficacy of early ASP intervention for patients with CoNS BSI identified by RDTs at the time of positive BCx. Disclosures J Ryan Bariola, MD, Infectious Disease Connect: Salary support|Merck: Grant/Research Support Tina Khadem, PharmD, Infectious Disease Connect: Salary support|Merck: Grant/Research Support Brian Potoski, PharmD, BCPS-AQ ID, Merck Group: Grant/Research Support Ryan K. Shields, PharmD, MS, Infectious Disease Connect: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Roche: Grant/Research Support.

2019. Understanding the Impact of COVID-19 Pandemic on Central Line-Associated Bloodstream Infections (CLABSIs): Expanding Analysis to the Microbiologic Level

Abstract Background Increases in central line-associated bloodstream infection (CLABSI) rates have been reported in association with the COVID-19 pandemic, particularly among Candida species and coagulase-negative Staphylococcal species (CoNS). We sought to further validate the impact of the COVID-19 pandemic on CLABSI trends and perform a microbiologic analysis. Methods This is an IRB-approved retrospective analysis of CLABSIs across a network of 38 community hospitals in southeastern United States. CLABSI rates were compared between pre-pandemic (1/1/2018-3/30/2020) and pandemic periods (4/1/2020-12/31/2021). Regression models were developed to evaluate CLABSI incidence over time. Likelihood ratio tests were used to compare models that were exclusively time-dependent to segmented regression models that also accounted for the COVID-19 pandemic. Results A total of 1,167 CLABSIs over 1,345,062 central line days were analyzed (Table 1). The mean monthly CLABSI rate per hospital increased from 0.63 to 1.01 per 1,000 central line days (p&amp;lt; 0.001) in the pandemic period (Table 1). CLABSIs secondary to Candida (0.16 to 0.33, p&amp;lt; 0.001), CoNS (0.09 to 0.22, p&amp;lt; 0.001), and Enterococcal species (0.06 to 0.18, p=0.001) increased, while Escherichia coli CLABSIs decreased (0.04 to 0.01, p&amp;lt; 0.001). Upon regression modeling, the COVID-19 pandemic was associated with increases in monthly CLABSI rates by Candida and Enterococcus species (Figure 1). In contrast, the changes in CoNS and Escherichia coli CLABSI rates were better explained by exclusively time-dependent models (Figure 1; Table 2). Non-sustained changes in Staphylococcus aureus and Klebsiella pneumoniae CLABSI rates were also noted (Table 2). Table 1:Count data, central line days, and mean monthly CLABSI incidence by organism per hospital. Rates are provided as CLABSIs per 1,000 central line days. Figure 1:Regression analysis of monthly CLABSI rates by pathogen. Gray areas denote COVID-19 pandemic period. Statistically significant level changes in CLABSI rates were observed among Candida and Enterococcus spp. (RR=1.92, CI 1.16-3.20 and 2.42, CI 1.09-5.38). Staphylococcus aureus CLABSI rates had a non-sustained but significant increase at the onset of COVID-19 (RR 2.20, CI 1.16-4.20). CoNS and E. coli rate changes occurred independent of COVID-19 (see Table 2). Table 2:Coefficient table of regression analyses for CLABSI rates by pathogen. Exclusively time-dependent models were compared to segmented regression models for each organism and, if no significant difference was noted between models, only the time-dependent model was applied. Conclusion The COVID-19 pandemic was associated with substantial increases in CLABSIs, driven in part by Candida and Enterococcus species across this network of hospitals. However, the observed increase in CoNS CLABSIs and decrease in Escherichia coli CLABSIs appear to have occurred independently of COVID-19, which only became apparent upon regression analysis. Interpretation of pre-post statistics without assessment of pre-existing trends should be done cautiously. Additional analyses may help elucidate other factors influencing these CLABSI trends by organism. Disclosures Sonali D. Advani, MBBS, MPH, FIDSA, Locus Biosciences: Advisor/Consultant|Locus Biosciences: Honoraria|Sysmex America: Advisor/Consultant Melissa D. Johnson, PharmD, MHS, AAHIVP, Charles River Laboratories: Grant/Research Support|Entasis: Honoraria|Merck: Grant/Research Support|Pfizer: Honoraria|Scynexis: Grant/Research Support|Theratechnologies: Honoraria|UpToDate: Honoraria.

Biofilm formation and inflammatory potential of Staphylococcus saccharolyticus: A possible cause of orthopedic implant-associated infections.

Staphylococcus saccharolyticus, a coagulase-negative staphylococcal species, has some unusual characteristics for human-associated staphylococci, such as slow growth and its preference for anoxic culture conditions. This species is a relatively abundant member of the human skin microbiota, but its microbiological properties, as well as the pathogenic potential, have scarcely been investigated so far, despite being occasionally isolated from different types of infections including orthopedic implant-associated infections. Here, we investigated the growth and biofilm properties of clinical isolates of S. saccharolyticus and determined host cell responses. Growth assessments in anoxic and oxic conditions revealed strain-dependent outcomes, as some strains can also grow aerobically. All tested strains of S. saccharolyticus were able to form biofilm in a microtiter plate assay. Strain-dependent differences were determined by optical coherence tomography, revealing that medium supplementation with glucose and sodium chloride enhanced biofilm formation. Visualization of the biofilm by confocal laser scanning microscopy revealed the role of extracellular DNA in the biofilm structure. In addition to attached biofilms, S. saccharolyticus also formed bacterial aggregates at an early stage of growth. Transcriptome analysis of biofilm-grown versus planktonic cells revealed a set of upregulated genes in biofilm-embedded cells, including factors involved in adhesion, colonization, and competition such as epidermin, type I toxin-antitoxin system, and phenol-soluble modulins (beta and epsilon). To investigate consequences for the host after encountering S. saccharolyticus, cytokine profiling and host cell viability were assessed by infection experiments with differentiated THP-1 cells. The microorganism strongly triggered the secretion of the tested pro-inflammatory cyto- and chemokines IL-6, IL-8, and TNF-alpha, determined at 24 h post-infection. S. saccharolyticus was less cytotoxic than Staphylococcus aureus. Taken together, the results indicate that S. saccharolyticus has substantial pathogenic potential. Thus, it can be a potential cause of orthopedic implant-associated infections and other types of deep-seated infections.