OBJECTIVES: Gram-positive cocci is the main pathogen responsible for early infection after liver transplantation (LT), posing a huge threat to the prognosis of liver transplant recipients. This study aims to analyze the distribution and drug resistance of Gram-positive cocci, the risk factors for infections and efficacy of antibiotics within 2 months after LT, and to guide the prevention and treatment of these infections. METHODS: In this study, data of pathogenic bacteria distribution, drug resistance and therapeutic efficacy were collected from 39 Gram-positive cocci infections among 256 patients who received liver transplantation from donation after citizens' death in the Third Xiangya Hospital of Central South University from January 2019 to July 2022, and risk factors for Gram-positive cocci infection were analyzed. RESULTS: Enterococcus faecium was the dominant pathogenic bacteria (33/51, 64.7%), followed by Enterococcus faecalis (11/51, 21.6%). The most common sites of infection were abdominal cavity/biliary tract (13/256, 5.1%) and urinary tract (10/256, 3.9%). Fifty (98%) of the 51 Gram-positive cocci infections occurred within 1 month after LT. The most sensitive drugs to Gram-positive cocci were teicoplanin, tigecycline, linezolid and vancomycin. Vancomycin was not used in all patients, considering its nephrotoxicity. Vancomycin was not administered to all patients in view of its nephrotoxicity.There was no significant difference between the efficacy of daptomycin and teicoplanin in the prevention of cocci infection (P>0.05). Univariate analysis indicated that preoperative Model for End-Stage Liver Disease (MELD) score >25 (P=0.005), intraoperative red blood cell infusion ≥12 U (P=0.013) and exposure to more than 2 intravenous antibiotics post-LT (P=0.003) were related to Gram-positive cocci infections. Multivariate logistic regression analysis revealed that preoperative MELD score >25 (OR=2.378, 95% CI 1.124 to 5.032, P=0.024) and intraoperative red blood cell transfusion ≥ 12 U (OR=2.757, 95% CI 1.227 to 6.195, P=0.014) were independent risk factors for Gram-positive cocci infections after LT. Postoperative Gram-positive cocci infections were reduced in LT recipients exposing to more than two intravenous antibiotics post-LT (OR=0.269, 95% CI 0.121 to 0.598, P=0.001). CONCLUSIONS Gram-positive cocci infections occurring early after liver transplantation were dominated by Enterococcus faecalis infections at the abdominal/biliary tract and urinary tract. Teicoplanin, tigecycline and linezolid were anti-cocci sensitive drugs. Daptomycin and teicoplanin were equally effective in preventing cocci infections due to Gram-positive cocci. Patients with high preoperative MELD score and massive intraoperative red blood cell transfusion were more likely to suffer Gram-positive cocci infection after surgery. Postoperative Gram-positive cocci infections were reduced in recipients exposing to more than two intravenous antibiotics post-LT.
Humans ; Daptomycin/therapeutic use* ; Linezolid/therapeutic use* ; Teicoplanin/therapeutic use* ; Gram-Positive Cocci ; Liver Transplantation/adverse effects* ; Tigecycline/therapeutic use* ; End Stage Liver Disease/drug therapy* ; Gram-Positive Bacterial Infections/microbiology* ; Severity of Illness Index ; Anti-Bacterial Agents/pharmacology* ; Vancomycin/therapeutic use* ; Microbial Sensitivity Tests

Infective endocarditis caused by Abiotrophia defectiva is rarely encountered. A 67-year-old male transferred from a local hospital presented with severe dyspnea and pulmonary edema. Preoperative transthoracic echocardiography revealed severe mitral regurgitation with large vegetation. Blood cultures grew A. defectiva, a gram positive, nutritionally deficient streptococcus variant. Emergent mitral valve replacement through right thoracotomy was performed, and after completing six weeks of antibiotic combination therapy (vancomycin, ampicillin, and gentamicin), the patient recovered fully. Because of the need for prompt surgical treatment and long-term antibiotic therapy and lack of laboratory experience with the organism, physicians and laboratory workers should pay close attention to the possibility of A. defectiva infective endocarditis when gram positive cocci are detected in blood cultures.
Abiotrophia ; Adult ; Aged ; Ampicillin ; Dyspnea ; Echocardiography ; Endocarditis ; Endocarditis, Bacterial ; Gram-Positive Cocci ; Humans ; Male ; Mitral Valve ; Mitral Valve Insufficiency ; Pulmonary Edema ; Streptococcus ; Thoracotomy

BACKGROUND: Blood culture is an important method for identifying infectious microorganisms and confirming that a selected antimicrobial treatment is appropriate. In this study, we investigated the annual changes in the frequencies of blood isolates and antibiotic susceptibility test (AST) results. METHODS: We created a large database comprising data on all patient-unique blood cultures obtained from January 2007 through December 2016. Blood specimens were cultured using the BD BACTEC FX system, and species identification and AST were performed using the VITEK 2 system. RESULTS: During the 10-year study period, a total of 203,651 blood culture results were collected. Of these, gram-positive cocci, gram-negative rods, and fungi were isolated in 2.15%, 0.55%, and 0.12% of the blood cultures, respectively. Escherichia coli was the most commonly isolated species (22.8%), followed by Staphylococcus epidermidis (16.8%), Klebsiella pneumoniae (8.1%), and Staphylococcus aureus (8.0%). Fungal species were isolated in 3.0% of all positive blood cultures. Candida albicans was the most commonly isolated species (1.1%), followed by Candida parapsilosis (0.6%). Methicillin resistance was seen in 55.2% of S. aureus isolates. The frequencies of vancomycin-resistant Enterococcus (VRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were 13.1% and 10.9%, respectively. The isolation rates of MRSA, VRE, and CRPA showed different patterns each year. CONCLUSIONS: Among the isolates, E. coli was the most common, followed by S. epidermidis and K. pneumoniae. This study represents a long-term analysis of bloodstream infections, and the results can be used to identify trends in the microorganisms isolated and their drug resistance.
Bacteremia ; Candida ; Candida albicans ; Drug Resistance ; Enterococcus ; Escherichia coli ; Fungi ; Gram-Positive Cocci ; Klebsiella pneumoniae ; Korea ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Methods ; Pneumonia ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Staphylococcus epidermidis

BACKGROUND: Antimicrobial resistant continues to pose a threat to public health. Therefore, rapid and accurate antimicrobial susceptibility testing is very important. The objectives of this study were to evaluate the performance of the MicroScan system (Beckman Coulter, USA) with newly developed Korean Antimicrobial Susceptibility Testing Panels (KSCM panels) for antimicrobial susceptibility testing (AST) against clinical isolates in South Korea. METHODS: Three KSCM panels were designed in this study. For the performance evaluation, a total of 1,325 clinical isolates including 1,027 of Gram-negative bacilli and 298 Gram-positive cocci collected from eight general hospitals in South Korea were used. The results by KSCM panels were compared with those by conventional methods. RESULTS: By KSCM-1 panel for Gram-positive cocci, the rates of categorical agreement (CA) were >90% in all the antimicrobials tested in this study. The rates of major error (ME) were also <3%, and only three very major error (VME) were identified; each of ampicillin, tetracycline, and quinupristin-dalfopristin in enterococcal isolates. By KSCM-2 panel for Enterobacteriaceae, the rates of CA were also above 90%, and those of ME and VME were less than 3% and 1.5%, respectively. KSCM-3 panels for glucose- non-fermenting Gram-negative bacilli, also showed good agreement rates, i.e., CA rates >90%, ME rates <3%, and VME rates <1.5%. CONCLUSION: The newly developed three KSCM panels for MicroScan system (Beckman Coulter) showed excellent performance in AST against a large number of clinical isolates, and they are applicable to clinical microbiology laboratories.
Ampicillin ; Enterobacteriaceae ; Gram-Positive Cocci ; Hospitals, General ; Hospitals, Teaching ; Korea ; Public Health ; Tetracycline

BACKGROUND: Timely intervention in the treatment of bloodstream infection is important for prescription of appropriate antimicrobials. With prompt determination of the antimicrobial susceptibility of a causative agent, rapid antimicrobial susceptibility test (AST) can help select the appropriate antimicrobial therapy. This clinical study is for evaluation of the clinical performance of the QMAC-dRAST for rapid AST directly from positive blood culture (PBC)s with Gram-positive cocci. METHODS: A total of 115 PBC samples with Gram-positive organisms (76 Staphylococcus spp. and 39 Enterococcus spp.) were evaluated by the QMAC-dRAST system, and their pure culture isolates were evaluated by the MicroScan WalkAway (Beckman Coulter, USA) as the comparative AST system. Thirteen antimicrobial agents were included, and the agreement and discrepancy rates of the QMAC-dRAST system (Quantamatrix Inc., Republic of Korea) compared to the MicroScan WalkAway were calculated. To resolve discrepancies, the broth microdilution method was performed. RESULTS: The QMAC-dRAST system exhibited a categorical agreement rate of 94.9% (1,126/1,187) and an essential agreement rate of 98.3% (1,167/1,187). The QMAC-dRAST system yielded very major (false-susceptible) errors at 1.0% (5/485), major (false-resistant) errors at 1.3% (9/693), and minor errors at 4.0% (47/1,187) compared to the MicroScan WalkAway. The QMAC-dRAST system significantly eliminated 30 hours of total turnaround time by combination of direct inoculation of PBC and an image-based approach. CONCLUSION: The results of the QMAC-dRAST system were highly accurate. Thereby, the QMAC-dRAST may provide essential information to accelerate therapeutic decisions for earlier and adequate antibiotic treatment and patient management in clinical settings.
Anti-Infective Agents ; Bacteremia ; Bioengineering ; Clinical Study ; Drug Resistance, Microbial ; Enterococcus ; Gram-Positive Cocci* ; Humans ; Methods ; Microbial Sensitivity Tests ; Prescriptions ; Staphylococcus

Globicatella sanguinis is an unusual pathogen causing bacteremia, meningitis, and urinary tract infection, and can be misidentified as Streptococcus pneumoniae or viridans streptococci due to its colonial morphology. A 76-year-old female patient with hypertension and degenerative arthritis was admitted to the hospital complaining of knee joint pain. Blood culture revealed the presence of Gram-positive cocci, and the isolated organism was equally identified as S. pneumoniae using the MicroScan identification system (Beckman Coulter, USA) and Vitek 2 identification system (bioMérieux, USA). However, the isolate showed optochin resistance based on the optochin disk susceptibility test. The organism was finally confirmed to be G. sanguinis based on 16S rRNA sequencing and hydrogen sulfide production testing. Accurate identification of G. sanguinis isolated from aseptic body fluids including blood is important for appropriate antibiotic selection based on accurate application of interpretative criteria of antimicrobial susceptibility test.
Aged ; Bacteremia* ; Body Fluids ; Female ; Gram-Positive Cocci ; Humans ; Hydrogen Sulfide ; Hypertension ; Knee Joint ; Meningitis ; Osteoarthritis ; Pneumonia ; Streptococcus pneumoniae ; Urinary Tract Infections ; Viridans Streptococci

BACKGROUND/AIMS: Wistar rat dams exposed to limited nesting stress (LNS) from post-natal days (PND) 2 to 10 display erratic maternal behavior, and their pups show delayed maturation of the hypothalamic-pituitary-adrenal axis and impaired epithelial barrier at PND10 and a visceral hypersensitivity at adulthood. Little is known about the impact of early life stress on the offspring before adulthood and the influence of sex. We investigated whether male and female rats previously exposed to LNS displays at weaning altered corticosterone, intestinal permeability, and microbiota. METHODS: Wistar rat dams and litters were maintained from PND2 to 10 with limited nesting/bedding materials and thereafter reverted to normal housing up to weaning (PND21). Control litters had normal housing. At weaning, we monitored body weight, corticosterone plasma levels (enzyme immunoassay), in vivo intestinal to colon permeability (fluorescein isothiocyanate-dextran 4 kDa) and fecal microbiota (DNA extraction and amplification of the V4 region of the 16S ribosomal RNA gene). RESULTS: At weaning, LNS pups had hypercorticosteronemia and enhanced intestinal permeability with females > males while body weights were similar. LNS decreased fecal microbial diversity and induced a distinct composition characterized by increased abundance of Gram positive cocci and reduction of fiber-degrading, butyrate-producing, and mucus-resident microbes. CONCLUSIONS: These data indicate that chronic exposure to LNS during the first week post-natally has sustained effects monitored at weaning including hypercorticosteronemia, a leaky gut, and dysbiosis. These alterations may impact on the susceptibility to develop visceral hypersensitivity in adult rats and have relevance to the development of irritable bowel syndrome in childhood.
Adult ; Animals ; Body Weight ; Colon ; Corticosterone* ; Dysbiosis ; Female ; Gram-Positive Cocci ; Housing ; Humans ; Hypersensitivity ; Irritable Bowel Syndrome ; Male ; Maternal Behavior ; Microbiota* ; Permeability* ; Plasma ; Rats* ; RNA, Ribosomal, 16S ; Stress, Psychological ; Weaning*

Streptococcus bovis bacteremia in humans has been traditionally associated with infective endocarditis, colorectal cancer, and liver cirrhosis. S. bovis strains were previously categorized by biotype, but since the 2000s, they have been reclassified by DNA homology. We report a case of S. gallolyticus subsp. gallolyticus bacteremia, identified by 16S rRNA sequencing, in a patient diagnosed with liver cirrhosis. A 61-yr-old man with a history of liver cirrhosis presented to the hospital with a complaint of fever. Blood culture revealed the presence of gram-positive cocci, and the isolated organism was identified as S. bovis by the MicroScan identification kit (Beckman Coulter, USA), but as Enterococcus saccharolyticus by the Vitek 2 identification kit (bioMérieux, USA). The organism was finally confirmed as S. gallolyticus subsp. gallolyticus by 16S rRNA sequencing.
Bacteremia* ; Colorectal Neoplasms ; DNA ; Endocarditis ; Enterococcus ; Fever ; Gram-Positive Cocci ; Humans ; Liver Cirrhosis* ; Liver* ; Streptococcus bovis ; Streptococcus*

Blood culture is important to detecting bacteremia and fungemia in patients with suspected sepsis. We observed a four-year trend of blood culture isolates in the frequency by age group and in vitro antimicrobial susceptibility patterns obtained at VHS Medical Center, the largest veterans hospital in Korea. Blood cultures collected between 2012 and 2015 were analysed retrospectively. Of 68,352 blood specimens, 7,901 isolates were identified during the study period. Seventy-two percent of the isolates were gram-positive cocci, 18% were gram-negative rods, and 6% were fungi. The frequency of bacteremia/fungemia in patients who were 80–89 years old was 43.8%, the highest rate among all age groups, and the mean age of patients diagnosed by blood culture was 77 years old. Coagulase-negative staphylococcus (52.3%), Staphylococcus aureus (8.3%), enterococci (7.5%), Escherichia coli (6.4%), and Klebsiella pneumoniae (3.9%) were the bacteria most commonly isolated. The percentage of methicillin-resistant S . aureus increased in 2015 (76%) relative to that in 2012–2014 (63%–65%), and that of vancomycin-resistant Enterococcus faecium was 17%–22% with no significant changes through time. Among the gram-negative isolates, the ciprofloxacin resistance rate increased to 51.4% (E. coli ) and 31.1% (K. pneumoniae ) in 2015, but imipenem or ertapenem resistance was still very rare, with resistance rates of less than 0.5%. Acinetobacter baumannii showed a high rate of resistance (over 70%) to imipenem and ciprofloxacin throughout the study. In Pseudomonas aeruginosa , the resistance rates of imipenem and ciprofloxacin increased dramatically over time. This analysis confirmed a decrease in antimicrobial susceptibility of gram-negative rods isolated by blood culture.
Acinetobacter baumannii ; Bacteremia ; Bacteria ; Ciprofloxacin ; Enterococcus faecium ; Escherichia coli ; Fungemia ; Fungi ; Gram-Positive Cocci ; Hospitals, Veterans* ; Humans ; Imipenem ; In Vitro Techniques ; Klebsiella pneumoniae ; Korea ; Methicillin Resistance ; Pneumonia ; Pseudomonas aeruginosa ; Retrospective Studies ; Sepsis ; Staphylococcus ; Staphylococcus aureus ; Veterans*

PURPOSE: To report a case of Staphylococcus lugdunensis endophthalmitis following cataract extraction and intraocular lens implantation. CASE SUMMARY: A 59-year-old woman presented with unilateral vision impairment and eyeball pain in her left eye, thirteen days after phacoemulsification and posterior chamber intraocular lens implantation. Best-corrected visual acuity of her left eye was 20/200. Slit lamp examination of her left eye revealed a severe conjunctival injection, severe chamber reactions with exudative membranes, hypopyon (about 1 mm) in the anterior chamber, and the fundus was not visible. Before the patient was admitted to the hospital, we cultured samples of aqueous fluid and performed an intravitreal antibiotics injection (vancomycin 1.0 mg/0.1 mL, ceftazidime 2.0 mg/0.1 mL). However, on the next day, because the inflammatory reactions of the anterior chamber and vitreous cavity were not improved and Gram positive cocci was confirmed, we performed a pars plana vitrectomy and an additional intravitreal antibiotics injection (vancomycin 1.0 mg/0.1 mL, dexamethasone 0.5 mg/0.1 mL). Seven days after the surgery, Staphylococcus lugdunensis was identified in the aqueous fluids culture. 11 days after the surgery, her inflammation and symptoms were improved and therefore, she could be discharged. Three months after the surgery, best-corrected visual acuity of her left eye was 20/20 and there was no evidence of recurrence of endophthalmitis and no abnormal findings in her fundus.
Anterior Chamber ; Anti-Bacterial Agents ; Cataract Extraction ; Cataract* ; Ceftazidime ; Dexamethasone ; Endophthalmitis* ; Female ; Gram-Positive Cocci ; Humans ; Inflammation ; Lens Implantation, Intraocular ; Membranes ; Middle Aged ; Phacoemulsification ; Recurrence ; Slit Lamp ; Staphylococcus lugdunensis* ; Staphylococcus* ; Visual Acuity ; Vitrectomy