Postoperative Staphylococcus aureus Infections in Patients With and Without Preoperative Colonization.

Importance: Staphylococcus aureus surgical site infections (SSIs) and bloodstream infections (BSIs) are important complications of surgical procedures for which prevention remains suboptimal. Contemporary data on the incidence of and etiologic factors for these infections are needed to support the development of improved preventive strategies. Objectives: To assess the occurrence of postoperative S aureus SSIs and BSIs and quantify its association with patient-related and contextual factors. Design, Setting, and Participants: This multicenter cohort study assessed surgical patients at 33 hospitals in 10 European countries who were recruited between December 16, 2016, and September 30, 2019 (follow-up through December 30, 2019). Enrolled patients were actively followed up for up to 90 days after surgery to assess the occurrence of S aureus SSIs and BSIs. Data analysis was performed between November 20, 2020, and April 21, 2022. All patients were 18 years or older and had undergone 11 different types of surgical procedures. They were screened for S aureus colonization in the nose, throat, and perineum within 30 days before surgery (source population). Both S aureus carriers and noncarriers were subsequently enrolled in a 2:1 ratio. Exposure: Preoperative S aureus colonization. Main Outcomes and Measures: The main outcome was cumulative incidence of S aureus SSIs and BSIs estimated for the source population, using weighted incidence calculation. The independent association of candidate variables was estimated using multivariable Cox proportional hazards regression models. Results: In total, 5004 patients (median [IQR] age, 66 [56-72] years; 2510 [50.2%] female) were enrolled in the study cohort; 3369 (67.3%) were S aureus carriers. One hundred patients developed S aureus SSIs or BSIs within 90 days after surgery. The weighted cumulative incidence of S aureus SSIs or BSIs was 2.55% (95% CI, 2.05%-3.12%) for carriers and 0.52% (95% CI, 0.22%-0.91%) for noncarriers. Preoperative S aureus colonization (adjusted hazard ratio [AHR], 4.38; 95% CI, 2.19-8.76), having nonremovable implants (AHR, 2.00; 95% CI, 1.15-3.49), undergoing mastectomy (AHR, 5.13; 95% CI, 1.87-14.08) or neurosurgery (AHR, 2.47; 95% CI, 1.09-5.61) (compared with orthopedic surgery), and body mass index (AHR, 1.05; 95% CI, 1.01-1.08 per unit increase) were independently associated with S aureus SSIs and BSIs. Conclusions and Relevance: In this cohort study of surgical patients, S aureus carriage was associated with an increased risk of developing S aureus SSIs and BSIs. Both modifiable and nonmodifiable etiologic factors were associated with this risk and should be addressed in those at increased S aureus SSI and BSI risk.

Spontaneous spondylodiscitis and epidural abscess due to Listeria monocytogenes in a middle-aged patient with gentamicin related side effects: A case report and a review of literature.

Introduction: Primary spondylodiscitis due to Listeria monocytogenes (LM) is a rare condition. Research question: We present a case of spontaneous LM spondylodiscitis with an epidural abscess in a middle-aged man, who reported no gastrointestinal infection. Material and methods: We identified 5 spinal infection cases due to LM in the literature, with 3 diagnosed as primary spondylodiscitis. Results: The patient was treated with surgical decompression, debridement, and antibiotic therapy. Blood cultures remained negative throughout the case and microbiological cultures were obtained during surgery. The patient developed side-effects of prolonged gentamicin therapy but made a recovery from his spinal complaints at 6-months follow-up. Listeriosis is a relatively rare food-borne disease with a wide spectrum of presentation. Surgeons should consider more aggressive therapy for spinal infections and recognize the uncommon manifestations. We identified 3 primary and 2 secondary LM spondylodiscitis cases in the literature. Antibacterial treatment of LM spondylodiscitis varied in agents and duration, but no side-effects were previously reported. Gentamicin treatment requires care and attention to complications. Discussion and conclusion: Listeria monocytogenes is a rare cause of primary spondylodiscitis. Further studies are needed to establish a safe treatment protocol for treatment with gentamicin and LM spondylodiscitis.

Prolonged outbreak of Serratia marcescens in Tartu University Hospital: a case-control study.

BACKGROUND: The aim of our study was to investigate and control an outbreak and identify risk factors for colonization and infection with Serratia marcescens in two departments in Tartu University Hospital. METHODS: The retrospective case-control study was conducted from July 2005 to December 2006. Molecular typing by pulsed field gel electrophoresis was used to confirm the relatedness of Serratia marcescens strains. Samples from the environment and from the hands of personnel were cultured. RESULTS: The outbreak involved 210 patients, 61 (29%) developed an infection, among them 16 were invasive infections. Multivariate analysis identified gestational age, arterial catheter use and antibiotic treatment as independent risk factors for colonization and infection with Serratia marcescens. Molecular typing was performed on 83 Serratia marcescens strains, 81 of them were identical and 2 strains were different. CONCLUSIONS: Given the occasionally severe consequences of Serratia marcescens in infants, early implementation of aggressive infection control measures involving patients and mothers as well as the personnel is of utmost importance.

Prevalence and antibiotic susceptibility of Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae in Estonian intensive care units in comparison with European data.

This prospective cohort study was performed from April to December 2003 for the purpose of collecting a maximum of 50 non-duplicate isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae from each of 4 ICUs to determine minimum inhibitory concentrations. The most prevalent species were Enterobacteriaceae (13%), K. pneumoniae and A. baumannii (both 12%). 60% of A. baumannii strains were susceptible to ampicillin/sulbactam and cefepime, 95% to meropenem and imipenem, and 75% to amikacin. 79% of P. aeruginosa strains were piperacillin/tazobactam, 58% ceftazidime, 81% meropenem, 72% imipenem, 69% ciprofloxacin and 97% amikacin susceptible. The susceptibility of K. pneumoniae to meropenem and imipenem was 99%, to ciprofloxacin was 91% and to amikacin was 98%. Gram-negative bacteria (especially K. pneumoniae and A. baumannii) were prevalent in our ICUs compared to other European studies. Carbapenem susceptibility of Estonian strains was higher, but P. aeruginosa sensitivity to ceftazidime was lower, compared to other EU countries.

The comparison of susceptibility patterns of Gram-negative invasive and non-invasive pathogens in Estonian hospitals.

A total of 560 invasive and 1062 non-invasive isolates were collected. The antimicrobial susceptibility of invasive versus non-invasive Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae isolates were evaluated using the E-tests. The equal domination of Gram-negative among both invasive and non-invasive pathogens was estimated in our study if contaminants were excluded. The emergence trend of Gram-positive microbes especially of coagulase negative staphylococci may be proved only after application of exclusive algorithms. Due to similar susceptibility, the data of non-invasive Gram-negative pathogens can be useful to predict resistance of invasive ones. Also, the surveillance of invasive pathogens provides useful information about the general susceptibility of pathogens.

Surgical-site infections following cesarean section in an Estonian university hospital: postdischarge surveillance and analysis of risk factors.

OBJECTIVES: To evaluate a multi-method approach to postdischarge surveillance of surgical-site infections (SSIs) and to identify infection rates and risk factors associated with SSI following cesarean section. DESIGN: Cross-sectional survey. SETTING: Academic tertiary-care obstetric and gynecology center with 54 beds. PATIENTS: All women who delivered by cesarean section in Tartu University Women's Clinic during 2002. METHODS: Infections were identified during hospital stay or by postdischarge survey using a combination of telephone calls, healthcare worker questionnaire, and outpatient medical records review. SSI was diagnosed according to the criteria of the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance System. RESULTS: The multi-method approach gave a follow-up rate of 94.8%. Of 305 patients, 19 (6.2%; 95% confidence interval [CI95], 3.8-9.6) had SSIs. Forty-two percent of these SSIs were detected during postdischarge surveillance. We found three variables associated with increased risk for developing SSI: internal fetal monitoring (odds ratio [OR], 16.6; CI95, 2.2-125.8; P = .007), chorioamnionitis (OR, 8.8; CI95, 1.1-69.6; P = .04), and surgical wound classes III and IV (OR, 3.8; CI95, 1.2-11.8; P = .02). CONCLUSIONS: The high response rate validated the effectiveness of this kind of surveillance method and was most suitable in current circumstances. A challenge exists to decrease the frequency of internal fetal monitoring and to treat chorioamnionitis as soon as possible.