Impact of viral testing on duration of antibiotic treatment and hospitalisation of febrile infants.

AIM: To assess the duration of antimicrobial treatment; hospital length of stay; and invasive bacterial infections rates in hospitalised infants following the adoption of a management guideline. METHODS: Faculty agreed to a standard of 24 h of antibiotic treatment for well-appearing febrile infants with proven viral infection and no growth on bacterial cultures. The outcomes were the duration of hospitalisation and antibiotic treatment of febrile infants less than 8 weeks of age who have enterovirus, parechovirus, respiratory viruses detected. We monitored re-admissions and missed invasive infections. RESULTS: Of the total 1696 infants studied, the median antibiotic treatment duration decreased from 31.5 to 24.8 h in virus-infected infants ≤21 days of age (p = 0.02) and from 26 to 19.7 h in infants 22-56 days of age (p < 0.001). The decrease was less in infants not infected with a virus. No patient had an invasive infection identified after discharge. CONCLUSION: The implementation of our care standard resulted in reduction in antibiotic treatment duration without known delayed diagnosis of bacterial infections. Infants without a proven viral aetiology may need further study to inform management decisions.

In vitro antimicrobial activity of silver nanoparticles against selected Gram-negative and Gram-positive pathogens.

Background and aim: Infections caused by pathogenic bacteria increase patient morbidity and mortality and significantly raise treatment costs. The use of silver nanoparticles as an alternative treatment for S aureus, E coli, MRSA, E faecalis, K pneumoniae and P aeruginosa indicates their antibacterial effect and prompts medical research to consider the next generation of antibacterial drugs that could change antibiotic therapy. By combining silver nanoparticles with different classes of antibiotics, the antibacterial effect is evidenced by increased values of the inhibition zone compared to the values obtained for some antibiotics commonly used in the treatment of bacterial infections. This study focuses on comparing the antibacterial activity of antibiotics versus antibiotics combined with silver nanoparticles against various bacteria, by comparing inhibition zones obtained for both. We aim to prove that the size of the inhibition zone for antibiotics combined with silver nanoparticles is greater, thus confirming the improved antibacterial effect. Metods: In this study we tested the antibacterial activity of solutions of silver nanoparticles alone or in combination with different antibiotics. We used standard bacterial strains, ATCC, both Gram positive bacteria Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, as well as Gram negative bacteria Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, but also on clinical isolates: a strain MRSA (Methicillin Resistant Staphylococcus aureus) and a PDR strain (pan drug resistant) of Klebsiella pneumoniae. Bacterial identification was performed using Vitek MS analyzer (bioMerieux). Antibiotic susceptibility determination was performed with VITEK2 COMPACT SYSTEM (bio Merieux, Inc Durham NC) with ready to use VITEK AST cards. The interpretation of the results was done in compliance with EUCAST 2023-2024 standards. Testing was performed for several classes of antibiotics, silver nanoparticle solutions in 2 concentrations (10 µg/mL and 100 µg/mL) and for combinations of antibiotics with silver nanoparticle solutions. The diameter of the inhibition zone (ZOI) for silver nanoparticles, antibiotics and silver nanoparticles combined with antibiotic against each bacterium was expressed in millimeters. The Kirby-Bauer disk-diffusion method, in accordance with current EUCAST standards, was used to analyze the antibacterial effect of antibiotics, silver nanoparticles, and antibiotics combined with silver nanoparticles at biocompatible doses of 10 and 100 µg/mL. The experiments were conducted in triplicate, and the results were almost identical. Results: The results of this study show that the silver nanoparticles displayed antibacterial activity, proven by the appearance of the inhibition zone, in various sizes, for all bacteria studied. The antibiotic classes tested were beta-lactamins, first, second, third and fourth generation cephalosporins, macrolides, fluoroquinolones, lincosamides, aminoglycosides, glycopeptides, tetracyclines, oxazolidinones, sulfonamides, rifamycins, amphenicols. Testing S aureus ATCC 29213, the highest zone of inhibition was demonstrated for cephalosporins (32.6667 ± 0.701 mm), macrolides (31.6667 ± 0.701 mm, and lincosamides (29.6667 ± 0.701 mm). Testing MRSA (internal code GR0333), the highest zone of inhibition for combination of silver nanoparticles and antibiotics was demonstrated for fluoroquinolones (36.3333 ± 0.701 mm), lincosamides (32.3333 ± 0.701 mm), Fusid acid (32.3333 ± 0.701 mm) and aminoglicosides (31.3333 ± 0.701 mm). Testing E coli ATCC 25922 the highest zone of inhibition was for Fosfomycine, 39 mm and for E faecalis ATCC 29212 for aminoglicosides was 19 mm. For K pneumoniae (internal code GQ8575) the inhibition zone for silver nanoparticles 100 µg/mL was 12.3333 ± 0.701 mm and for P aeruginosa ATCC 27253 was 16 ± 1.214 mm. Conclusions: The use of metallic nanoparticles, especially silver ones, as antimicrobial agents with definite bactericidal activity has led medical specialists to consider this new treatment which may change antibacterial therapy. Studies of in vitro combinations between silver nanoparticles and different classes of antibiotics represent a highly efficient and effective new antibacterial treatment against multidrug-resistant bacteria. To avoid the problem of antimicrobial resistance associated with conventional antibiotics, it is necessary to understand the adaptive mechanisms of bacteria under the action of metal nanoparticles, which could be exploited in future studies. Further in vitro and in vivo studies that would assess specify the biocompatibility and toxicity of silver nanoparticles will make these super nanomaterials the medicines of the future.

Management of acute uncomplicated diverticulitis and adherence to current guidelines-a multicentre SNAPSHOT study.

PURPOSE: To explore whether previous participation in clinical studies increases adherence to management guidelines in acute uncomplicated diverticulitis (AUD). METHODS: This retrospective cohort study was designed to give a SNAPSHOT of the management of AUD at six hospitals, three of which had participated in the AVOD trial comparing antibiotic versus non-antibiotic treatment of AUD. Patients with AUD were included from March 2019 through June 2020 and followed for 90 days. The primary outcome was treatment of AUD categorised by antibiotic treatment and inpatient or outpatient management compared between AVOD and non-AVOD hospitals. Descriptive statistics were compiled, and differences between hospitals were assessed with Pearson's chi-squared test. RESULTS: The cohort included 449 patients with AUD of which 63% were women and the median age was 63 (IQR: 52-73) years. Patient characteristics were comparable across the hospitals. Antibiotics were administered to 84 (19%) patients and 113 (25%) patients were managed as inpatients. Management varied significantly between AVOD and non-AVOD hospitals. The mean proportion of patients treated with antibiotics was 7% at AVOD hospitals compared to 38% at non-AVOD hospitals (p < 0.001). The mean proportion of in-hospital management was 18% at AVOD hospitals versus 38% at non-AVOD hospitals (p < 0.001). CONCLUSION: Most patients with AUD were managed according to current guidelines. However, the management varies between hospitals and previous participation in clinical studies may increase knowledge of and adherence to guidelines.

Development and external validation of a model to predict multidrug-resistant bacterial infections in patients with cirrhosis.

With the increasing rate of infections caused by multidrug-resistant organisms (MDRO), selecting appropriate empiric antibiotics has become challenging. We aimed to develop and externally validate a model for predicting the risk of MDRO infections in patients with cirrhosis. METHODS: We included patients with cirrhosis and bacterial infections from two prospective studies: a transcontinental study was used for model development and internal validation (n = 1302), and a study from Argentina and Uruguay was used for external validation (n = 472). All predictors were measured at the time of infection. Both culture-positive and culture-negative infections were included. The model was developed using logistic regression with backward stepwise predictor selection. We externally validated the optimism-adjusted model using calibration and discrimination statistics and evaluated its clinical utility. RESULTS: The prevalence of MDRO infections was 19% and 22% in the development and external validation datasets, respectively. The model's predictors were sex, prior antibiotic use, type and site of infection, MELD-Na, use of vasopressors, acute-on-chronic liver failure, and interaction terms. Upon external validation, the calibration slope was 77 (95% CI .48-1.05), and the area under the ROC curve was .68 (95% CI .61-.73). The application of the model significantly changed the post-test probability of having an MDRO infection, identifying patients with nosocomial infection at very low risk (8%) and patients with community-acquired infections at significant risk (36%). CONCLUSION: This model achieved adequate performance and could be used to improve the selection of empiric antibiotics, aligning with other antibiotic stewardship program strategies.

Osteomyelitis-relevant antibiotics at clinical concentrations show limited effectivity against acute and chronic intracellular S. aureus infections in osteocytes.

Osteomyelitis caused by Staphylococcus aureus can involve the persistent infection of osteocytes. We sought to determine if current clinically utilized antibiotics were capable of clearing an intracellular osteocyte S. aureus infection. Rifampicin, vancomycin, levofloxacin, ofloxacin, amoxicillin, oxacillin, doxycycline, linezolid, gentamicin, and tigecycline were assessed for their minimum inhibitory concentration (MIC) and minimum bactericidal concentrations against 12 S. aureus strains, at pH 5.0 and 7.2 to mimic lysosomal and cytoplasmic environments, respectively. Those antibiotics whose bone estimated achievable concentration was commonly above their respective MIC for the strains tested were further assayed in a human osteocyte infection model under acute and chronic conditions. Osteocyte-like cells were treated at 1×, 4×, and 10× the MIC for 1 and 7 days following infection (acute model), or at 15 and 21 days of infection (chronic model). The intracellular effectivity of each antibiotic was measured in terms of CFU reduction, small colony variant formation, and bacterial mRNA expression change. Only rifampicin, levofloxacin, and linezolid reduced intracellular CFU numbers significantly in the acute model. Consistent with the transition to a non-culturable state, few if any CFU could be recovered from the chronic model. However, no treatment in either model reduced the quantity of bacterial mRNA or prevented non-culturable bacteria from returning to a culturable state. These findings indicate that S. aureus adapts phenotypically during intracellular infection of osteocytes, adopting a reversible quiescent state that is protected against antibiotics, even at 10× their MIC. Thus, new therapeutic approaches are necessary to cure S. aureus intracellular infections in osteomyelitis.

Enterococci independently increase the risk for initial antibiotic treatment failure and prolonged hospitalization in adult patients with complicated urinary tract infection: a retrospective cohort study.

OBJECTIVES: We aimed to investigate the impact of enterococci on initial antibiotic treatment (IAT) failure and prolonged hospitalization in complicated urinary tract infection (cUTI) cases, and to identify risk factors for enterococcal cUTI. METHODS: Adult cUTI patients were analyzed to compare the differences between the Enterococcus and non-Enterococcus groups. Univariate and multivariate analyses were employed to identify independent risk factors. RESULTS: This study included 419 patients, with the Enterococcus group showing significantly higher IAT failure rates and an extended average length of stay by 4.4 days compared to the non-Enterococcus group. Multivariate analysis identified enterococci, hospital-acquired UTIs (HA-UTI), indwelling catheters, and bed rest (bedridden) as independent risk factors for IAT failure. Enterococci were notably linked to prolonged hospitalization, other independent risk factors included IAT failure, prior antimicrobial use, age-adjusted Charlson comorbidity index (ACCI) ≥ 4, hypoalbuminemia, and bed rest. Urological cancer, HA-UTI, indwelling catheters, urinary retention, and urologic surgery were risk factors for enterococcal cUTI. CONCLUSION: We provide the first evidence that enterococci independently increase the risk for IAT failure and prolonged hospitalization in adults with cUTIs, highlighting the significance of timely identification to optimize measures including antibiotic regimens. Risk factors for enterococcal cUTI have also been identified to aid clinicians in managing this condition.

Adaptability of the gut microbiota of the German cockroach Blattella germanica to a periodic antibiotic treatment.

High-throughput sequencing studies have shown that diet or antimicrobial treatments impact animal gut microbiota equilibrium. However, properties related to the gut microbial ecosystem stability, such as resilience, resistance, or functional redundancy, must be better understood. To shed light on these ecological processes, we combined advanced statistical methods with 16 S rRNA gene sequencing, functional prediction, and fitness analyses in the gut microbiota of the cockroach Blattella germanica subject to three periodic pulses of the antibiotic (AB) kanamycin (n=512). We first confirmed that AB did not significantly affect cockroaches' biological fitness, and gut microbiota changes were not caused by insect physiology alterations. The sex variable was examined for the first time in this species, and no statistical differences in the gut microbiota diversity or composition were found. The comparison of the gut microbiota dynamics in control and treated populations revealed that (1) AB treatment decreases diversity and completely disrupts the co-occurrence networks between bacteria, significantly altering the gut community structure. (2) Although AB also affected the genetic composition, functional redundancy would explain a smaller effect on the functional potential than on the taxonomic composition. (3) As predicted by Taylor's law, AB generally affected the most abundant taxa to a lesser extent than the less abundant taxa. (4) Taxa follow different trends in response to ABs, highlighting "resistant taxa," which could be critical for community restoration. (5) The gut microbiota recovered faster after the three AB pulses, suggesting that gut microbiota adapts to repeated treatments.

What Makes It Tick: Exploring the Mechanisms of Post-treatment Lyme Disease Syndrome.

Post-treatment Lyme disease syndrome (PTLDS), which may also be referred to incorrectly as "chronic Lyme disease," is defined by the Infectious Diseases Society of America (IDSA) as the presence of fatigue, pain, and/or cognitive complaints with the functional impact that persists for more than six months after completing treatment for Lyme disease (LD). These symptoms occur in 10%-20% of patients previously diagnosed with LD caused by the bacteria Borrelia burgdorferi and appropriately treated with a course of antibiotics. The symptoms of PTLDS can be easily overlooked or misdiagnosed as a psychiatric manifestation in geographic locations that rarely see LD. In contrast, geographic locations with a higher prevalence of LD may be more aware of PTLDS symptoms and have higher clinical suspicion leading to this diagnosis. The pathophysiology behind the persistent symptoms some people experience from a primary infection is still largely unknown. Some mechanisms that have been proposed include permanent tissue damage and inflammation, immune system dysfunction, autoimmune response, co-infection, and even persistent infection refractory to treatment. We propose that ongoing PTLDS symptoms seem to be related to an autoimmune response to the tissue damage and inflammation caused by the viable or nonviable spirochete pathogen. At this point, PTLDS is diagnosed clinically as no quantifiable methods are available from laboratory or tissue diagnostics as of 2024. Similar pathophysiological features of PTLDS are seen in diseases such as COVID-19 or chronic fatigue syndrome (CFS). More effective diagnostic approaches might include further studies looking at a possible connection in the genomes of individuals developing PTLDS, quantifiable biomarkers, common inflammatory markers/pathways, and careful histopathological studies of human tissues.

Necrotizing Fasciitis Due to Group A Streptococcus: A Case of a Deteriorating Biphasic-like Clinical Course Over Five Days with a Devastating Outcome.

Necrotizing fasciitis (NF) is a life-threatening disease with high mortality and rapidly progressive clinical manifestations1. Early detection and surgical management coupled with antibiotic treatment are crucial for the survival, and the patient survival is heavily dependent on clinical decisions2,3. However, it is not widely known that NF does not always follow a typical clinical course, and there have been no case reports of NF following an atypical clinical course. Although the course of the disease depends on the individual patient, it remains a challenge for physicians to determine the precise timing when patients are most likely to survive multiple surgical interventions. We encountered a challenging case presenting with an atypical clinical course. We herein report a 31-year-old man who followed a deteriorating biphasic-like clinical course and presented with extensive NF and streptococcal toxic shock syndrome due to Group A Streptococcus. This case serves to inform physicians of the existence of NF with an atypical and deteriorating biphasic-like clinical course, emphasizing the need for a careful evaluation of the patient condition.

Agar and agarose used for Staphylococcus aureus biofilm cultivation impact fluoroquinolone tolerance.

AIMS: Staphylococcus aureus is an opportunistic pathogen whose treatment is further complicated by its ability to form biofilms. In this study, we examine the impact of growing S. aureus biofilms on different polymerizing surfaces, specifically agar and agarose, on the pathogen's tolerance to fluoroquinolones. METHODS AND RESULTS: Biofilms of two methicillin-resistant strains of S. aureus were grown on agar or agarose in the presence of the same added nutrients, and their antibiotic susceptibility to two fluoroquinolones, moxifloxacin (MXF) and delafloxacin (DLX), were measured. We also compared the metabolism and extracellular polymeric substances (EPS) production of biofilms that were grown on agar and agarose. CONCLUSIONS: Biofilms that were grown on agarose were consistently more susceptible to antibiotics than those grown on agar. We found that in biofilms that were grown on agar, extracellular protein composition was higher, and adding EPS to agarose-grown biofilms increased their tolerance to DLX to levels that were comparable to agar-grown biofilms.

Adherence to Antibiotic Prescription Guidelines in Four Community Hospitals in Germany.

This retrospective study aimed to assess and compare guideline adherence and treatment costs in the management of urinary tract infections (UTIs) and bloodstream infections (BSIs) in German tertiary hospitals from January 2019 to December 2020. The study analyzed 586 patient records, with 65% diagnosed with UTIs and 35% with BSIs. Antibiotic treatment was given to 98% of patients, but only 65% received microbiological diagnostics. Bacterial growth was observed in 86% of patients with cultures taken, with Escherichia coli being the leading pathogen. The treatment was intravenous in 63% of cases, with Ceftriaxone as the leading antibiotic agent. The guideline adherence was found to be low, at 33%. Multivariable logistic regression analysis revealed that patients with urogenital risk factors (OR = 1.589; p < 0.001) and increasing age (OR = 1.01; p = 0.007) were significantly more likely to receive guideline-concordant treatment for UTIs and BSIs. Additionally, complicating factors such as diabetes and renal dysfunction were associated with higher adherence rates, underscoring the importance of targeted antibiotic stewardship interventions.

Peripheral Intravenous Therapy in Internal Medicine Department-Antibiotics and Other Drugs' Consumption and Characteristics of Vascular Access Devices in 2-Year Observation Study.

BACKGROUND: The aim of the study was to characterize the procedure of peripheral intravenous therapy (IT), including the characteristics of vascular access and related complications and qualitative and quantitative analyses of drug consumption. MATERIALS AND METHODS: A two-year, retrospective, single-center observational study was conducted. The criterion for including a patient in the study was the use of peripheral intravenous catheters (PIVCs) upon admission or during the stay at the internal medicine department (IMD). RESULTS: The main reasons for hospitalization were exacerbations of chronic diseases for 78% of the patients and acute infections for 22%. IT was used in 83.6% of all the patients. IT was used primarily for antibiotics (5009.9 defined daily doses (DDD)). Further, 22.6% of the PIVCs stopped functioning within 24 h, more frequently in infectious patients. The main reasons for PIVC removal were leakage (n = 880, 26.6%) and occlusion (n = 578, 17.5%). The PIVC locations were mostly suboptimal (n = 2010, 59.5%), and such locations were related to leakage and occlusion (p = 0.017). CONCLUSIONS: In the IMD, most patients require the use of a PIVC, and antibiotics dominate the group of drugs administered intravenously. Up to 1/5 of peripheral intravenous catheters are lost within the first 24 h after their insertion, with most of them placed suboptimally. A properly functioning PIVC appears to be crucial for antimicrobial treatment.

Assay Interference Causing Persistently Elevated Vancomycin Levels Leading to Treatment Failure and Fatal Outcome.

In patients receiving vancomycin therapy, serum drug levels are routinely monitored to ensure therapeutic dosing and minimize toxicity. In rare cases, vancomycin levels may be falsely or persistently elevated without any apparent cause. In this case report, we explore a rare case of persistently elevated vancomycin levels despite discontinuation of the drug for days.  This is a case of a 69-year-old female admitted for altered mental status secondary to sepsis from leg cellulitis. Antibiotic therapy included vancomycin. To ensure proper dosing, vancomycin trough levels were collected before the fourth dose, and the result showed a high value of 39 ug/ml. Vancomycin doses were adjusted as per the Bayesian dosing software, and the same remained to be in supratherapeutic levels. The patient eventually deteriorated, and due to persistently high vancomycin levels, the antibiotic regimen was switched to a different antibiotic. Despite normal renal functions, the vancomycin levels remained high, between 27 ug/ml and 32 ug/ml, even in the absence of any further doses. Subsequently, vancomycin serum concentration was determined by another method using high-performance liquid chromatography (HPLC). Blood cultures grew both coagulase-negative Staphylococcus aureus and Achromobacter xylosoxidans. Vancomycin levels remained high a week after discontinuation of the drug. Vancomycin by HPLC assay eventually showed that vancomycin was undetectable in the blood, but, unfortunately, the results came at a time when the patient had already expired. In conclusion, clinicians should maintain a high level of suspicion if persistently higher vancomycin levels cannot be accounted for by renal function or other causes. In patients with persistently high vancomycin levels who continue to clinically deteriorate, it is crucial to consider that assay interference can result in inaccurately elevated vancomycin levels.

A Difficult Differential Diagnosis in New Neck Masses: Retropharyngeal Abscess or Malignancy?

Retropharyngeal abscesses (RPAs) are rare in the adult population and rarer without an inciting event or comorbidity such as recent oral surgery, neck infection, or pharyngeal trauma. The definitive treatment is incision and drainage of the abscess. Clinical researchers have recently questioned whether invasive surgical intervention is necessary and posed the question of what role antibiotics play in management. Sequelae of RPAs are severe and include rupture of the abscess, erosion of the carotid artery, thrombophlebitis, and most seriously, airway compromise. We present a case where an atypical presentation of an RPA caused a disagreement among specialists, and the debate of whether the described case represented an abscess or malignancy caused a delay in diagnosis and treatment for the patient. Only after invasive and emergent surgical intervention was a final diagnosis able to be made. This case demonstrates the need for more research and official guidance on the management of new neck masses to hasten diagnosis and prevent devastating outcomes.

A Retrospective Cohort Study on Treponema pallidum Infection: Clinical Trends and Treatment Outcomes for Congenital Syphilis in Guangxi, China (2013-2023).

Background: Syphilis, a prevalent sexually transmitted infection, poses severe risks, especially during pregnancy. This study aimed to elucidate the trends and impacts of syphilis in Guangxi, China, focusing on prevalence, clinical manifestations, and treatment outcomes in pregnant women and newborns. The objectives included understanding the demographic characteristics of affected pregnant women, analysing the clinical manifestations in newborns, and assessing the effectiveness of the treatment protocol. Methods: Conducted in adherence to ethical guidelines, a retrospective cohort study from January 2013 to December 2023 included 54,048 pregnant women tested for T. pallidum. Diagnosis involved a comprehensive approach, utilizing tests like the Toluidine Red Unheated Serum Test (TRUST) and the Treponema pallidum Particle Agglutination (TPPA) assay. Infant diagnosis and clinical manifestations were evaluated through a decade-long follow-up. Treatment protocols, including Benzathine penicillin, were implemented. Statistical analyses were conducted using SAS version 9.4. Results: Among 54,048 pregnant women, 0.10% were syphilis positive, correlating with a rise in hospitalizations. Newborns exhibited varied clinical manifestations, with neonatal pneumonia and jaundice being prevalent. The treatment protocol, especially with Benzathine penicillin, achieved a remarkable 100% cure success rate. The study noted a significant reduction in mother-to-child transmission. Syphilis in mothers and babies was diagnosed at different clinical stages, including primary, secondary, latent, and tertiary. Conclusion: This study underscores the escalating impact of syphilis on pregnant women and newborns in Guangxi, China. The findings highlight the necessity for robust preventive measures, early diagnosis, and effective treatment strategies. The observed 100% cure success rate with Benzathine penicillin emphasizes the importance of strict treatment protocols in mitigating the adverse effects of congenital syphilis and reducing its transmission.

Case Report: The Conundrum of What to Pick? Antibiotic Susceptibility Variability in Burkholderia cenocepacia in Cystic Fibrosis: Implications for Antibiotic Susceptibility Testing and Treatment.

Within cystic fibrosis microbiology, there is often mismatch between the antibiotic susceptibility result of an isolated bacterial pathogen and the clinical outcome, when the patient is treated with the same antibiotic. The reasoning for this remains largely elusive. Antibiotic susceptibility to four antibiotics (ceftazidime, meropenem, minocycline and trimethoprim-sulfamethoxazole) was determined in consecutive isolates (n = 11) from an adult cystic fibrosis patient, over a 63 month period. Each isolate displayed its own unique resistotype. The first isolate was sensitive to all four antibiotics, in accordance with Clinical and Laboratory Standards Institute methodology and interpretative criteria. Resistance was first detected at four months, showing resistance to ceftazidime and meropenen and intermediate resistance to minocycline and trimethoprim-sulfamethoxazole. Pan resistance was first detected at 18 months (resistotype IV), with three resistotypes (I, II and III) preceding this complete resistotype. The bacterium continued to display further antibiotic susceptibility heterogeneity for the next 45 months, with the description of an additional seven resistotypes (resistotypes V-XI). The Relative Resistance Index of this bacterium over the 63 month period showed no relationship between the development of antibiotic resistance and time. Adoption of mathematical modelling employing multinomial distribution demonstrated that large numbers of individual colony picks (>40/sputum), would be required to be 78% confident of capturing all 11 resistotypes present. Such a requirement for large numbers of colony picks combined with antibiotic susceptibility-related methodological problems creates a conundrum in biomedical science practice, in providing a robust assay that will capture antibiotic susceptibility variation, be pragmatic and cost-effective to deliver as a pathology service, but have the reliability to help clinicians select appropriate antibiotics for their patients. This study represents an advance in biomedical science as it demonstrates potential variability in antibiotic susceptibility testing with Burkholderia cenocepacia. Respiratory physicians and paediatricians need to be made aware of such variation by biomedical scientists at the bench, so that clinicians can contextualise the significance of the reported susceptibility result, when selecting appropriate antibiotics for their cystic fibrosis patient. Furthermore, consideration needs to be given in providing additional guidance on the laboratory report to highlight this heterogeneity to emphasise the potential for misalignment between susceptibility result and clinical outcome.

The most common mistakes in intensive care - antibiotics.

The enormous increase in antibiotic resistance and the limited spectrum of new, effective antibiotics are the reasons why we should think about a rational approach to anti-infective therapy. The excessive and non-indicated use of antibiotics while treating critically ill patients can be found quite often in clinical practice. Antibiotic therapy is usually indicated empirically, or it is only based on therapeutic indecision, not just in ICU patients. The antibiotics are administered before taking a sample for microbiological analysis or there is no therapy adjustment based on the laboratory findings. The solution lies in antibiotic stewardship, which is the way to ensure that antibiotics will be sufficiently effective in years to come.

Is Aggressive Surgery Always Necessary for Suspected Early-Onset Surgical Site Infection after Lumbar Surgery? A 10-Year Retrospective Analysis.

OBJECTIVE: Surgical site infection (SSI) after spinal surgery is still a persistent worldwide health concern as it is a worrying and devastating complication. The number of samples in previous studies is limited and the role of conservative antibiotic therapy has not been established. This study aims to evaluate the clinical efficacy and feasibility of empirical antibiotic treatment for suspected early-onset deep spinal SSI. METHODS: We conducted a retrospective study to identify all cases with suspected early-onset deep SSI after lumbar instrumented surgery between January 2009 and December 2018. We evaluated the potential risks for antibiotic treatment, examined the antibiotic treatment failure rate, and applied logistic regression analysis to assess the risk factors for empirical antibiotic treatment failure. RESULTS: Over the past 10 years, 45 patients matched the inclusion criteria. The success rate of antibiotic treatment was 62.2% (28/45). Of the 17 patients who failed antibiotic treatment, 16 were cured after a debridement intervention and the remaining one required removal of the internal fixation before recovery. On univariate analysis, risk factors for antibiotic treatment failure included age, increasing or persisting back pain, wound dehiscence, localized swelling, and time to SSI (cut-off: 10 days). Multivariate analysis revealed that infection occurring 10 days after primary surgery and wound dehiscence were independent risk factors for antibiotic treatment failure. CONCLUSION: Appropriate antibiotic treatment is an alternative strategy for suspected early-onset deep SSI after lumbar instrumented surgery. Antibiotic treatment for suspected SSI occurring within 10 days after primary surgery may improve the success rate of antibiotic intervention. Patients with wound dehiscence have a significantly higher likelihood of requiring surgical intervention.

Antimicrobials administration, treatment outcome and bacterial susceptibility in canine pyometra cases subjected to ovariohysterectomy.

Pyometra is a bacterial uterine infection that frequently affects intact older bitches. The treatment of choice is ovariohysterectomy, often associated with perioperative antimicrobial therapy. The aim of this retrospective investigation was to evaluate the antibiotic choice at different administration times (pre-surgery, at surgery/during hospitalization, and post-surgery) against complications and outcomes, considering the susceptibility profile of bacteria. The medical records of 51 bitches referred to the Veterinary Teaching Hospital of the University of Turin (January 2021-November 2023) and subjected to ovariohysterectomy and bacteriological examination (bacterial culture and susceptibility tests) of the uterine exudate, were analysed. All animals had a positive outcome without surgical site infections, with a longer hospitalization time in case of peritonitis or sepsis; antimicrobials were administered for an average of 7 days. Comparing the susceptibility of the isolated bacteria towards the antimicrobials administered before, during and after surgery, complete efficacy was observed in 42 %, 46 % and 50 % of cases, respectively. In addition, 5/16 peritonitis cases were treated with an in vitro ineffective antimicrobial, and 30 % of the bitches never received a fully effective antibiotic, according to susceptibility tests using the minimum inhibitory concentration method (MIC). Cephazolin resulted the best option for Escherichia coli, the most frequently isolated bacterium. Our study confirms that pyometra has a good prognosis following ovariohysterectomy and antibiotic administration. Monitoring the clinical evolution without changing the antibiotic according to bacterial susceptibility could represent the right choice in uncomplicated cases. Evaluation of outcomes without postoperative antibacterial treatment or with a shorter course would be another topic worth investigating, with the aim to judiciously reduce the use of antibiotics.