Abdominal surgical site infections (SSIs) are infections that occur after abdominal surgery. They can be superficial, involving the skin tissue only, or more profound, involving deeper skin tissues including organs and implanted materials. Currently, SSIs are large global health problem with an incidence that varies significantly depending on the United Nations' Human Development Index. The purpose of this review is to provide a practical update on the latest available literature on SSIs, focusing on causative pathogens and treatment with an overview of the ongoing studies of new therapeutic strategies.

Bacteraemia during the course of neutropenia is often fatal. We aimed to identify factors predicting mortality to have an insight into better clinical management.

The study has a prospective, observational design using pooled data from febrile neutropenia patients with bacteraemia in 41 centres in 16 countries. Polymicrobial bacteraemias were excluded. It was performed through the Infectious Diseases-International Research Initiative platform between 17 March 2021 and June 2021. Univariate analysis followed by a multivariate binary logistic regression model was used to determine independent predictors of 30-d in-hospital mortality (sensitivity, 81.2%; specificity, 65%).

A total of 431 patients were enrolled, and 85 (19.7%) died. Haematological malignancies were detected in 361 (83.7%) patients. Escherichia coli (n = 117, 27.1%), Klebsiellae (n = 95, 22% %), Pseudomonadaceae (n = 63, 14.6%), Coagulase-negative Staphylococci (n = 57, 13.2%), Staphylococcus aureus (n = 30, 7%), and Enterococci (n = 21, 4.9%) were the common pathogens. Meropenem and piperacillin-tazobactam susceptibility, among the isolated pathogens, were only 66.1% and 53.6%, respectively. Pulse rate (odds ratio [OR], 1.018; 95% confidence interval [CI], 1.002-1.034), quick SOFA score (OR, 2.857; 95% CI, 2.120-3.851), inappropriate antimicrobial treatment (OR, 1.774; 95% CI, 1.011-3.851), Gram-negative bacteraemia (OR, 2.894; 95% CI, 1.437-5.825), bacteraemia of non-urinary origin (OR, 11.262; 95% CI, 1.368-92.720), and advancing age (OR, 1.017; 95% CI, 1.001-1.034) were independent predictors of mortality. Bacteraemia in our neutropenic patient population had distinctive characteristics. The severity of infection and the way to control it with appropriate antimicrobials, and local epidemiological data, came forward.

Local antibiotic susceptibility profiles should be integrated into therapeutic recommendations, and infection control and prevention measures should be prioritised in this era of rapidly increasing antibiotic resistance.

Pneumonia is common in the intensive care unit (ICU), infecting 27% of all critically ill patients. Given the high prevalence of this disease state in the ICU, optimizing antimicrobial therapy while minimizing toxicities is of utmost importance. Inappropriate antimicrobial use can increase the risk of antimicrobial resistance, Clostridiodes difficile infection, allergic reaction, and other complications from antimicrobial use (e.g., QTc prolongation, thrombocytopenia). This review article aims to discuss methods to optimize antimicrobial treatment in patients with pneumonia, including the following: procalcitonin use, utilization of methicillin-resistant Staphylococcus aureus nares testing to determine need for vancomycin therapy, utilization of the Biofire^® FilmArray^® pneumonia polymerase chain reaction (PCR), and microbiology reporting techniques.

Retrospective cohort study.

This study aimed to investigate the characteristics of microflora in patients with deep spinal surgical site infection (SSI) after prophylactic use of vancomycin powder (VP).

A retrospective analysis was performed on patients after spinal surgery. Patients were grouped according to whether VP use and only patients with deep SSI were included in this study. General information of the patients, the dose of vancomycin, bacterial culture results, drug sensitivity test results, and SSI treatment methods were recorded. The differences of microflora between the two groups were analyzed, and the sensitivity of bacteria in the +VP group to antibiotics was analyzed.

The infection rate in the +VP group was 4.9% (56/1124) vs 6.3% (93/1476) in the No-VP group (P < 0.05). The proportion of Gram-positive bacteria (GPB) in the +VP SSIs was 55.4% vs.74.1% in the No-VP group (P < 0.05). The percentage of Gram-negative bacteria (GNB) in the +VP SSIs was 46.4% vs.30.1% in the No-VP group (P < 0.05). More dose of VP cannot decrease the SSI, but the proportion of GNB in VP >1g SSIs was higher (59.0% vs 32.4%, P < 0.05). In the +VP SSIs, all of the GNB cultured were sensitive to meropenem, and linezolid covered most of the GPB cultured.

Local use of vancomycin powder can reduce the incidence of SSI, but this may lead to changes in the bacterial flora. Once the SSI occurs, the case of GNB infection may be increased. The more dose of VP cannot decrease SSI but may increase the rate of GNB in the +VP SSIs. Once infections still occur after VP use, antibiotics covering GNB may be added. These findings may help guide choice of empiric antibiotics while awaiting culture data.

The number of days of preoperative hospital stay (PHS) is a modifiable variable that has shown contradictory surgical site infection (SSI) risk factor results in neurosurgery. We sought to pinpoint the day of PHS length related with a marked increase of risk of SSI.

From a tertiary teaching hospital, January 2015-December 2017, prospectively collected nonpercutaneous neurosurgery procedures with standard antibiotic prophylaxis and 1-year follow-up were evaluated. SSI risk factors were assessed through multiple logistic regression models with different thresholds of PHS.

A total of 1012 procedures were included in the study. Incidence of SSI was 4.4%. The median PHS was higher in those with SSI than in those without (1 day, interquartile range [IQR]: 7 vs. 0 days, IQR: 1, respectively, P = 0.002). By the amount of six days of PHS, this exposure risk past the threshold of significance for impact on wound infection (OR 2.8; CI 1.23-6.39, P = 0.014). Operative time past 4 h (OR 2.11; CI 1.12-3.98; P = 0.021), and in some models, previous surgery at same admission were also identified by multivariate analysis as increasing postoperative SSI risk.

The gradual increase of the SSI OR associated with longer PHS days was the highest risk factor of SSI in our cohort of patients. Studies directed to reduce this complication should consider the PHS.

Introduction: Spontaneous bacterial peritonitis (SBP) is a main infectious complication in end-stage liver disease (ESLD) patients. The increasing trend of bacterial resistance in ESLD patients with SBP has been associated with low treatment efficacy of traditional therapy. Cephalosporin use has been restricted to community-acquired infections and in areas/health care settings with low rates of multidrug-resistant (MDR) bacteria. To date, several changes are necessary with regard to empiric therapy recommendations in areas/health care settings with high rates of MDR bacteria. Areas covered: An overview of the epidemiology and antimicrobial treatments of SBP caused by Gram-negative bacteria. Expert opinion: Broad-spectrum antibiotics have been recommended as empiric therapy for suspected SBP in areas/health care settings with high rates of MDR bacteria and secondary treatment, with newer antibiotics, for SBP caused by MDR-Gram-negative bacteria (i.e. new beta-lactam/beta-lactamase inhibitor combinations, cefiderocol, plazomicin, and eravacycline) either alone or in combination.

Complicated intra-abdominal infections (cIAIs) are a common cause of morbidity and mortality in surgical patients. Optimal management of cIAI requires early source control in combination with adequate antimicrobial treatment and aggressive fluid resuscitation. cIAIs are mainly caused by Gram-negative bacilli and anaerobes. Broad-spectrum single-agent or combination drug regimens against these microorganisms are the mainstay of therapy. However, development of antimicrobial resistance has become an increasingly large concern: multidrug-resistant organisms are associated with a higher rate of inadequate antimicrobial therapy, which in turn is associated with higher mortality rate, longer hospital stay, and increased cost compared to adequate antimicrobial therapy. In this mini-review, we discuss the effectiveness of several new antimicrobial agents, recently approved or in advanced phases of clinical development, for the treatment of cIAIs, including the new beta-lactam and beta-lactamase inhibitor combinations (ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilastatin/relebactam, aztreonam/avibactam), siderophore cephalosporins (cefiderocol), aminoglycosides (plazomicin), and tetracyclines (eravacycline).

Antibiotic use and immunocompromised status in haematology patients have been shown to determine the constituents of commensal microbiota with highly increased resistance, including vancomycin resistant enterococci. We compared the carriage of virulence factor genes and the capacity for biofilm formation in vancomycin resistant enterococci (VRE) originating from the oropharyngeal and stool cultures of haematology patients.

PCR tests were used to investigate the presence of genes encoding pathogenicity factors (esp and hyl) in VRE isolates. The genotype of vancomycin resistance was investigated by multiplex PCR tests for vanA and vanB genes. PFGE typing was conducted to exclude the duplicate isolates.

Of 3310 pharyngeal swabs taken from inpatients at a clinic for haematology, Enterococcus species were recovered in 6.46%. All VRE investigated were identified as Enterococcus faecium and were highly vancomycin resistant. VanA genotype was confirmed in all. In the group of oropharyngeal carriers (n = 8 patients), 15 strains were recovered from oropharyngeal specimens and PFGE typing revealed 5 types and 3 subtypes. Identical types of VRE in the oropharynx and stool cultures were found in three patients from this group. In the group of stool carriers (n = 24 patients) VRE were obtained from stools only and placed in 21 macro-restriction patterns. The esp gene was more common in VRE isolated from the oropharynx than in isolates from stools (p = 0.014). Results were not significant when we compared the presence of hyl genes in oropharyngeal isolates with those from stool cultures (p = 0.66) or when we investigated the association between esp and hyl gene carriage and capability of biofilm formation in non-repeated VRE.

In the present study, isolation of VRE from the oropharynx in haematology patients was associated with esp gene carriage. Further research is needed to investigate the clinical and long-term effects of this finding.

Fungal infections of the liver, most commonly caused by Candida spp., often occur in patients with hematologic malignancies treated with chemotherapy. Colonization of the gastrointestinal tract is thought to be the main origin of dissemination of Candida; mucositis and neutropenia facilitate the spread of Candida from the gastrointestinal tract to the liver. Hepatic involvement due to other fungi is a less common infectious complication in this setting. Fungal infections represent a less common cause of hepatic abscesses in non-oncohematologic population and the trend appears to be decreasing in recent years. Understanding of the etiology and epidemiology of fungal infections of the liver is indicated for an appropriate antimicrobial therapy and an overall optimal management of fungal liver infections.

Spontaneous bacterial peritonitis (SBP) is the most common infection in end-stage liver disease patients. SBP is defined as an ascitic fluid infection with a polymorphonuclear leucocyte count ≥ 250/mm3 without an evident intra-abdominal surgically treatable source. Several mechanisms contribute to SBP occurrence, including translocation of gut bacteria and their products, reduced intestinal motility provoking bacterial overgrowth, alteration of the gut's barrier function and local immune responses. Historically, Gram-negative enteric bacteria have been the main causative agents of SBP, thereby guiding the empirical therapeutic choice. However, over the last decade, a worryingly increasing prevalence of Gram-positive and multi-drug resistant (MDR) SBP has been seen. Recently, the microbiological spectrum of SBP seems to have changed in Europe due to a high prevalence of Gram-positive bacteria (48%-62%). The overall proportion of MDR bacteria is up to 22%-73% of cases. Consequently, empirical therapy based on third-generation cephalosporins or amoxicillin/clavulanic acid, can no longer be considered the standard of care, as these drugs are associated with poor outcomes. The aim of this review is to describe, with an epidemiological focus, the evidence behind this rise in Gram-positive and MDR SBP from 2000 to present, and illustrate potential targeted therapeutic strategies. An appropriate treatment protocol should include daptomycin plus ceftaroline and meropenem, with prompt stepdown to a narrower spectrum when cultures and sensitivity data are available in order to reduce both cost and potential antibiotic resistance development.

Recent data highlight the importance of screening more than one site for improving the detection of S. aureus colonization. Intestinal carriage is frequently under-investigated and its clinical impact ought to be defined a better way. Areas covered: This review and meta-analysis provide an updated overview of prevalence, characteristics and clinical significance of S. aureus intestinal carriage in different populations, both for methicillin-susceptible and -resistant S. aureus strains. Expert commentary: Intestinal S. aureus carriage is documented with higher prevalence in children and in patients with S. aureus skin and soft tissue infections. This site of colonization was shown to be associated with a high risk of dissemination in the environment and with S. aureus infection. Intestinal carriage is frequently retrieved in nasal carriers, reflecting probably an association with a high bacterial load. Exclusive intestinal carriage present in one third of intestinal carriers can be associated with infection. Comparative genotyping analysis of different strains from nasal and extra-nasal sites of carriage, including the intestinal ones, in the same individuals, would allow a better comprehension of the pathophysiology of S. aureus endogenous infection. It could also permit to improve the prevention of these infections by decolonization of sites implicated in infection genesis.

Staphylococci are a significant cause of hospital-acquired infection. Nasal carriage of Staphylococcus aureus is an important risk factor for infection in surgical patients and coagulase-negative staphylococci (CNS) are a major cause of prosthetic joint infections. The impact that antibiotic surgical prophylaxis has on the nasal carriage of staphylococci has not been studied. Daily nasal swabs were taken from 63 patients who received antibiotic surgical prophylaxis and 16 patients who received no antibiotics. Total aerobic bacterial count, S. aureus and CNS were enumerated by culture from nasal swabs. Representative isolates were typed by staphylococcal interspersed repeat units (SIRU) typing and PFGE, and MICs to nine antibiotics were determined. After antibiotic administration, there was a reduction in S. aureus counts (median - 2.3 log(10)c.f.u. ml(- 1)) in 64.0 % of S. aureus carriers, compared with only a 0.89 log(10)c.f.u. ml(- 1) reduction in 75.0 % of S. aureus carriers who did not receive antibiotics. A greater increase in the nasal carriage rate of meticillin-resistant CNS was observed after antibiotic surgical prophylaxis compared with hospitalization alone, with increases of 16.4 and 4.6 %, respectively. Antibiotic-resistant S. epidermidis carriage rate increased by 16.6 % after antibiotic administration compared with 7.5 % with hospitalization alone. Antibiotic surgical prophylaxis impacts the nasal carriage of both S. aureus and CNS.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of healthcare-associated infections. Recent legislative mandates require nares screening for MRSA at hospital and intensive care unit (ICU) admission in many states. However, MRSA colonization at extranasal sites is increasingly recognized. We conducted a systematic review of the literature to identify the yield of extranasal testing for MRSA.

We searched MEDLINE from January 1966 through January 2012 for articles comparing nasal and extranasal screening for MRSA colonization. Studies were categorized by population tested, specifically those admitted to ICUs and those admitted to hospitals with a high prevalence (6% or greater) or low prevalence (less than 6%) of MRSA carriers. Data were extracted using a standardized instrument.

We reviewed 4,381 abstracts and 735 articles. Twenty-three articles met the criteria for analysis ((n = 39,479 patients). Extranasal MRSA screening increased the yield by approximately one-third over nares alone. The yield was similar at ICU admission (weighted average, 33%; range, 9%-69%) and hospital admission in high-prevalence (weighted average, 37%; range, 9%-86%) and low-prevalence (weighted average, 50%; range, 0%-150%) populations. For comparisons between individual extranasal sites, testing the oropharynx increased MRSA detection by 21% over nares alone; rectum, by 20%; wounds, by 17%; and axilla, by 7%.

Extranasal MRSA screening at hospital or ICU admission in adults will increase MRSA detection by one-third compared with nares screening alone. Findings were consistent among subpopulations examined. Extranasal testing may be a valuable strategy for outbreak control or in settings of persistent disease, particularly when combined with decolonization or enhanced infection prevention protocols.

Antibiotics are among the most common pharmaceutical agents used by the interventional radiologist. This article updates some of the practical aspects of the use of antibiotics in interventional radiological practice and provides some general guidelines with respect to indications for and selection of antibiotics. In particular, the objectives of this article are to review the basic pharmacology of the common antibiotic agents, the interventional radiological procedures in which prophylactic antibiotics are usually administered, the specific antimicrobial agents recommended for prophylaxis before common interventional radiological procedures, the appropriate antibiotics for patients allergic to penicillins, and the indications for antibiotic prophylaxis to prevent bacterial endocarditis.

Implant infection remains a feared complication after total hip replacement. A higher rate of infection is observed after revision surgery. An additional threat for such patients arises from the fact that bacteria resistant to a multitude of antibiotics are encountered with increasing frequency in the hospital setting. Among them enterobacteria producing extended spectrum beta-lactamases (ESBL) are the second most frequent group of multiresistant isolates. ESBLs are enzymes which hydrolyse third and fourth generation cephalosporins resulting in a distinctive resistance against these antibiotics. Even though ESBLs were first described in the early 1980's and now represent pathogens of importance in intensive care units, they have been only rarely encountered in orthopaedic and trauma surgery. We report on three cases of ESBL-associated infections in hip arthroplasty, resulting in 1) resolution of infection after removal of the hip implant, 2) death after developing a nosocomial pulmonary infection due to ESBL-producing bacteria, and 3) resolution of infection after two-stage revision. The infections, caused by multi-resistant ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates, demonstrate the difficulties in managing implant associated infections with resistant bacteria, and emphasize the importance of recognizing ESBL-positive bacteria as increasingly important pathogens that require special precautions and treatment. Our observations suggest that ESBL-expressing bacteria in orthopaedic and trauma surgery are not a rare phenomenon any more.

Although antibiotic prophylaxis is not explicitly indicated for hernia repair and breast surgery, its use for these clean procedures is widely adopted, albeit to a different extent in different countries, often on the personal decision of the individual surgeon. The present study was carried out to compare the efficacy of a single pre-operative dose of piperacillin-tazobactam with placebo in preventing surgical wound infections and to determine the main risk factors associated with infections following two main elective surgical clean procedures such as hernia repair and breast surgery.A total of 501 patients undergoing elective inguinal/femoral hernia repair or breast surgery were enrolled in this prospective randomized clinical study. Patients were randomly assigned to receive preoperative antibiotic prophylaxis or placebo. One dose of piperacillin-tazobactam 2.250 g or placebo was administered i.v. 30 minutes prior to the surgical procedure. Using statistical univariate analysis, the following variables were correlated with a higher infection risk: age >40 years, concomitant disease, WBC <3500, surgical wound size >9cm, use of drainages, non-prophylaxis. Using multivariate analysis, no antibiotic pre-operative prophylaxis, concurrent chronic diseases, especially diabetes (risk 15 times higher), and length of intervention >45 min (risk 6 times higher) were independent predictors of infection. Finally, patients with postoperative infections had a significantly longer hospitalisation. One pre-operative dose of piperacillin-tazobactam 2.250 g is more effective than placebo in preventing postoperative infections in breast surgery and hernia repair.

Hospital-based monitoring is one of the methods used to collect data about drug prescriptions and adverse events. The aim of this 20-day observational prospective study was to evaluate the frequency and type of adverse reaction to antibiotics, and predisposing risk factors in inpatients in six departments of a university hospital (ophthalmology, paediatrics, internal medicine, general surgery, infectious diseases, anaesthesiology and intensive care). The data on all inpatients undergoing antibiotic treatment were collected by physicians trained by our team and validated by an expert panel. Data were recorded on pre-formatted confidential cards (MIO-card). In the 171 inpatients evaluated (125 adults: 39.5% male, mean age 61.6 years, range 21-93; and 46 children: 50% male; mean age 4.75 years, range 3 months-12 years), cefazolin (19.9%), chloramphenicol (18.6%), ceftriaxone (15.4%) and netilmicin (12.9%) were the most frequently used antibiotics. Adverse events occurred in four adults and three children: one had leucopenia (trimethoprim/sulfamethoxazole), one nephrotoxicity (netilmicin+teicoplanin) and one nephrotoxicity (cefotaxime), one diarrhoea (ceftriaxone), one neurotoxicity (isoniazid), one angioneurotic oedema (piperacillin) and one skin rashes (ceftriaxone). A number of strategies (educative and persuasive, facilitative and restrictive) have been proposed to improve antibiotic use. Our study suggests that hospital-based monitoring is a good method with which to detect links between drug exposure and adverse drug reactions in children and adults.