Can leucocyte esterase replace frozen sections in the intraoperative diagnosis of prosthetic hip infection?

AIMS: Leucocyte esterase (LE) has been shown to be an accurate marker of prosthetic joint infection (PJI), and has been proposed as an alternative to frozen section (FS) histology for intraoperative diagnosis. In this study, the intraoperative assessment of LE was compared with FS histology for the diagnosis of prosthetic hip infection. PATIENTS AND METHODS: A total of 119 patients undergoing revision total hip arthroplasty (THA) between June 2015 and December 2017 were included in the study. There were 56 men and 63 women with a mean age of 66.2 years (27 to 88). Synovial fluid was collected before arthrotomy for the assessment of LE using enzymatic colourimetric strips. Between five and six samples were stained with haematoxylin and eosin for FS histology, and considered suggestive of infection when at least five polymorphonuclear leucocytes were found in five high-power fields. RESULTS: The sensitivity and specificity of the LE assay were 100% and 93.8%, respectively; the positive (PPV) and the negative (NPV) predictive values were 79.3% and 100%, respectively. The mean time between the collection of the sample and the result being known was 20.1 minutes (sd 4.4). The sensitivity and specificity of FS histology were 78.3% and 96.9%, respectively; the PPV and the NPV were 85.7% and 94.9%, respectively. The mean time between the collection of the sample and the result being known was 27.2 minutes (sd 6.9). CONCLUSION: The sensitivity of LE assay was higher, with similar specificity and diagnostic accuracy, compared with FS histology. The faster turnaround time, its ease of use, and low costs make LE assay a valuable alternative to FS histology. We now use it routinely for the intraoperative diagnosis of PJI. Cite this article: Bone Joint J 2019;101-B:372-377.

Modulation of opportunistic species Corynebacterium diphtheriae, Haemophilus parainfluenzae, Moraxella catarrhalis, Prevotella denticola, Prevotella melaninogenica, Rothia dentocariosa, Staphylococcus aureus and Streptococcus pseudopneumoniae by intranasal administration of Streptococcus salivarius 24SMBc and Streptococcus oralis 89a combination in healthy subjects.

OBJECTIVE: Probiotics S. salivarius 24SMBc and S. oralis 89a comprised in the nasal spray Rinogermina are known to exert inhibition of harmful pathogens and ameliorate the outcome of patients with chronic upper airways infections. In this study, for the first time, the effect of this formulation on the modulation of the microflora of healthy subjects was evaluated, with particular interest on pathobionts and pathogens present. PATIENTS AND METHODS: Metagenomic identification and quantification of bacterial abundances in healthy subjects were carried out by means of Ion Torrent Personal Machine. In particular, nasal swabs were sampled one, two and four weeks after seven days of treatment with Rinogermina. RESULTS: The modulation of the abundance of pathobionts and pathogenic species (i.e., Corynebacterium diphtheriae, Haemophilus parainfluenzae, Moraxella catarrhalis, Prevotella denticola, Prevotella melaninogenica, Rothia dentocariosa, Staphylococcus aureus and Streptococcus pseudopneumoniae) was characterized and a significant temporary decrease in their presence was identified. CONCLUSIONS: The beneficial effects of S. salivarius 24SMBc and S. oralis 89a nasal intake was assessed but seemed to be restricted in specific temporal windows. Thus it would be interesting to evaluate also this positive impact of longer administration of this probiotic formulation.

Hyaluronic Acid and Its Composites as a Local Antimicrobial/Antiadhesive Barrier.

Living in biofilms is probably the most common condition for bacteria and fungi and biofilm-related infections account for the majority of bacterial infectious diseases worldwide. Among others biofilm-related infections, those associated with implanted biomaterials have an enormous and still largely underestimated impact in orthopaedics and trauma, cardio-surgery and several other surgical disciplines. Given the limited efficacy of existing antibiotics in the prevention and treatment of bacterial biofilms, new strategies are needed to protect implants and host tissues, overcoming the striking ability of the microorganisms to adhere on different surfaces and to immediately protect themselves by forming the biofilm matrix. Adhesion is a necessary first step in microbial colonization and pathogenesis and provides a potential target for new preventive and treatment approach. Among various polymers, tested as antibacterial coatings, hyaluronic acid and some of its composites do offer a well-established long-term safety profile and a proven ability to reduce bacterial adhesion and biofilm formation. Aim of the present review is to summarize the available evidence concerning the antiadhesion/antibiofilm activity of hyaluronic acid and some of its derivatives to reduce/prevent bacterial adhesion and biofilm formation in various experimental and clinical settings.

Leucocyte esterase, glucose and C-reactive protein in the diagnosis of prosthetic joint infections: a prospective study.

Analysis of joint fluid is of paramount importance for the diagnosis of prosthetic joint infections. Different markers of inflammation and/or infection in joint fluid have been proposed for diagnosis of these infections. In this study we evaluated the performance of leucocyte esterase, C-reactive protein (CRP) and glucose assays in synovial fluids from 129 patients with septic (n = 27) or aseptic (n = 102) prosthetic joint failure. Samples were collected in serum tubes and centrifuged to limit the presence of corpuscle interfering with the assays. Determinations of leucocyte esterase and glucose were carried out by means of enzymatic colorimetric reactions performed on strips for urine analysis. Tests were considered positive when graded + or ++ whereas traces or absence of colour were considered negative. CRP was measured using an automated turbidimetric method and considered suggestive for infections when >10 mg/L. Leucocyte esterase was positive in 25/27 infected patients and negative in 99/102 not infected patients (sensitivity 92.6%, specificity 97.0%). CRP was higher than the threshold in 22/27 infected patients and in 6/102 not infected patients (sensitivity: 81.5%; specificity: 94.1%) whereas glucose showed the lowest sensitivity (77.8%) and specificity (81.4%), being negative in 21/27 and 19/102 infected and not infected patients, respectively. CRP led to a correct diagnosis in 19 of 22 patients with discordant esterase and glucose results. In conclusion, evaluation of leucocyte esterase, glucose and CRP may represent a useful tool for rapid diagnosis of prosthetic joint infections.

ANTIBIOTIC-LOADED REGENOSS FOR THE TREATMENT OF SEPTIC BONE DEFECTS: IN VITRO STUDY AND PRELIMINARY CLINICAL EXPERIENCE.

Bone and joint infections are a difficult to treat condition, often associated with bone loss. Although the management of septic bone defects may currently be achieved through various treatment modalities, there is a continuous need for bone substitutes able at the same time to favour bone repair and to provide local antibacterial protection. RegenOss, a biomimetic and resorbable bone substitute, has been previously shown to be highly biocompatible and osteoconductive. Aims of the present study were to test the in vitro ability of RegenOss to act as a local carrier of antibiotics and to investigate its clinical safety and efficacy in a continuous series of patients, affected by bone loss in active or previous infection. In vitro study was performed by adding vancomycin, levofloxacin or meropenem and assessing elution properties of RegenOss at fixed time intervals by means of a microbiological assay. At 48 hours, 98.5% of meropenem, 94.1% of levofloxacin and 76.3% of vancomycin were recovered in the medium, while all antibiotics were completely eluted at seven days. Clinical safety and efficacy of vancomicyn- or vancomicyn and meropenem-loaded RegenOss had been tested in 13 consecutive patients. After the surgical procedure, each patient underwent clinical, laboratory and radiographic evaluation at 3, 6, 12, 18 and 24 months. No adverse events associated with the use of RegenOss were observed. Twelve patients showed no infection recurrence and ten satisfactory bone healing at follow-up. In conclusion, this study shows the ability of RegenOss to act as local carrier when loaded with three different antibiotics with a complete elution in one week. The clinical use of antibiotic-loaded RegenOss appears safe in this preliminary clinical series, while larger studies are needed to confirm the efficacy of the intra-operative combination of this biomimetic bone substitute with various antibacterials in the treatment of septic bone defects.

Prolonging culture to 15 days improves bacterial detection in bone and joint infections.

Since the optimal incubation period of cultures for diagnosis of bone and joint infections is still a matter of debate, the present study aimed to evaluate the effects of different incubation periods (5 and 15 days) on microbial isolation. Samples from 387 patients with bone and joint infections (including prosthetic ones) were analyzed from March 2012 to February 2014. In 197 patients (51 %) growth was obtained within 48 hrs, while in 124 (32 %) and 66 (17 %) patients cultures yielded positive results within and after 5 days of incubation, respectively. Of 449 microorganisms isolated, 247 grew within 48 hrs, 131 within the first 5 days of incubation while 71 were isolated after 5 days. Staphylococcus aureus was the most frequently isolated pathogen within 48 hrs, while Propionibacteria were prevalently isolated after 5 days of incubation. Interestingly, about 25 % of microorganisms isolated after 5 days of incubation were coagulase-negative staphylococci. Extending incubation period of broth cultures improves isolation rates of pathogens involved in bone and joint infections thus improving management of these infections.

Surgical site and early urinary tract infections in 1000 kidney transplants with antimicrobial perioperative prophylaxis.

Surgical site infections (SSIs) and early urinary tract infections (UTIs) are well recognized postoperative kidney transplant complications. These complications seldom lead to graft loss, although they may result in significant morbidity with prolonged hospitalization. Thus, perioperative antibiotic prophylaxis (PAP) has traditionally been used in this setting. Between April 1988 and December 2012, we identified 1000 kidney transplant recipients (33 from living donors) who underwent prophylaxis with ceftriaxone before the surgical procedure. A retrospective analysis was conducted to evaluate both the incidence rate and outcome of SSIs and UTIs. Recipients who developed SSIs were also assessed to identify risk factors and potential correlations with different immunosuppressive regimens. A total of 20 SSIs (2%) and 93 UTIs (9.3%) were observed. The most significant risk factor for SSIs was urine leak (15.38%; odds ratio [OR], 12.3; P < .0001) followed by sirolimus-based maintenance immunosuppression therapy (5%; OR, 2.97; P = .04) and induction therapy with either antithymocyte globulin or basiliximab (3.18%; OR, 3.45; P = .01). Sex was identified as the only risk factor for UTI (female vs male, 17.1% vs 4.6%; P < .0001). We believe universal ceftriaxone-based prophylaxis is useful for preventing SSIs and UTIs, considering its effectiveness and safety profile.

A comparative study of the use of bioactive glass S53P4 and antibiotic-loaded calcium-based bone substitutes in the treatment of chronic osteomyelitis: a retrospective comparative study.

The treatment of chronic osteomyelitis often includes surgical debridement and filling the resultant void with antibiotic-loaded polymethylmethacrylate cement, bone grafts or bone substitutes. Recently, the use of bioactive glass to treat bone defects in infections has been reported in a limited series of patients. However, no direct comparison between this biomaterial and antibiotic-loaded bone substitute has been performed. In this retrospective study, we compared the safety and efficacy of surgical debridement and local application of the bioactive glass S53P4 in a series of 27 patients affected by chronic osteomyelitis of the long bones (Group A) with two other series, treated respectively with an antibiotic-loaded hydroxyapatite and calcium sulphate compound (Group B; n = 27) or a mixture of tricalcium phosphate and an antibiotic-loaded demineralised bone matrix (Group C; n = 22). Systemic antibiotics were also used in all groups. After comparable periods of follow-up, the control of infection was similar in the three groups. In particular, 25 out of 27 (92.6%) patients of Group A, 24 out of 27 (88.9%) in Group B and 19 out of 22 (86.3%) in Group C showed no infection recurrence at means of 21.8 (12 to 36), 22.1 (12 to 36) and 21.5 (12 to 36) months follow-up, respectively, while Group A showed a reduced wound complication rate. Our results show that patients treated with a bioactive glass without local antibiotics achieved similar eradication of infection and less drainage than those treated with two different antibiotic-loaded calcium-based bone substitutes.

Behaviour of perioperative values of haemoglobin, haematocrit and red blood cells in elderly patients undergoing lower limb arthroplasty: a retrospective cohort study on non-transfused patients.

Little is known on how elderly patients recover pre-operative haemoglobin, haematocrit and red blood cell levels after total hip and knee arthroplasties. In this study we aimed to evaluate blood loss and recovery blood levels in relation to gender, type of surgery and preoperative haemoglobin values. We conducted a retrospective cohort study on 187 patients over 65 years of age who underwent total knee or total hip arthroplasty between January 2008 and December 2009. Preoperative blood analysis was carried out within 40 days prior to intervention followed by a 15-day postoperative follow-up. Haemoglobin recovery values in anaemic patients versus healthy patients was also estimated. All tested values decreased significantly during the first 3-5 postoperative days. Haemoglobin levels decreased statistically significantly more in males than in females, while no significant differences were observed for haematocrit and erythrocytes. Recovery of haemoglobin values did not differ significantly between healthy patients and patients with preoperative haemoglobin below 120 g/L. Furthermore, our data showed a higher blood loss in total hip arthroplasty, whilst recovery rates showed to be higher after a total knee arthroplasty procedure. In conclusion, the type of intervention and gender played an important role in blood loss and recovery rates in total joint arthroplasty.

In vitro selection of antibiotic resistance in the probiotic strain Lactobacillus rhamnosus GG ATCC 53103.

Antibiotic resistance in probiotic strains is a matter of interest due to the increase in consumption of probiotic products. Many studies have evaluated the antibiotic susceptibility of lactobacilli or the presence of resistance determinants, while knowledge on selection of resistance during exposure to antibiotics is still limited. Our aim was to evaluate the behavior of Lactobacillus rhamnosus GG ATCC 53103, a well-known probiotic microorganism, during exposure to erythromycin, tetracycline, amoxicillin/ clavulanate and ciprofloxacin. Our study demonstrated that prolonged exposure to erythromycin and ciprofloxacin could select mutants with reduced susceptibility, even if these modifications in susceptibility could not be attributed to known antibiotic resistance genes or genetic mutations.

Procalcitonin, C-reactive protein, interleukin-6, and soluble intercellular adhesion molecule-1 as markers of postoperative orthopaedic joint prosthesis infections.

There is a universally recognized need to identify new, reliable markers of inflammation that can aid in the rapid diagnosis of orthopaedic joint prosthesis infections (OJP-Is). Since prompt diagnosis is key to timely intervention in the course of infection, different molecules have been studied. In this study, we examined three groups of patients: those with prosthesis infection, those without infection, and a third group with previous infection in whom the infection had been cleared. Four presumed markers of infection were tested: procalcitonin (PCT); C-reactive protein (CRP); interleukin-6 (IL-6); and soluble intercellular adhesion molecule-1 (sICAM-1). The results showed that PCT cannot be considered as a good marker of periprosthetic infection as no statistically significant difference in serum PCT levels emerged between patients with infection and controls or patients without infection. In contrast, both sICAM-1 and CRP may be considered as good markers of infection, as measurement of their levels allowed us to distinguish between patients with and without infection, and between patients with infection and those with previous infection, since marker levels quickly returned to baseline values after clearance of the infection. IL-6 was found to be a good marker for inflammation, as it distinguished between patients with infection and the other groups. In the patients with previous infection, the IL-6 values remained high versus the controls but lower and with a statistically significant difference versus the patients with infection. Further studies are needed to determine the cut-off value of IL-6 between patients with infection and those with previous infection.

Comparative evaluation of synergy of combinations of beta-lactams with fluoroquinolones or a macrolide in Streptococcus pneumoniae.

OBJECTIVES: Streptococcus pneumoniae has shown a great ability to develop efficacious mechanisms of resistance to the main drugs for the treatment of pneumonia, such as ß-lactams, macrolides and fluoroquinolones. The present study aimed to compare the antipneumococcal activity of combinations of respiratory fluoroquinolones with cephalosporins (either parenteral or oral) or protected penicillin versus the standard combinations (i.e. a macrolide with a protected penicillin or cephalosporin) against 100 isolates with different susceptibilities to macrolides and/or penicillin. METHODS: Chequerboard assays for all isolates and time-kill curves for nine isolates with different patterns of susceptibility were performed. Synergy between antibiotics at serum peak concentrations was also determined. RESULTS: The combination of levofloxacin with ceftriaxone produced the highest rate of synergy (54/100), mainly against macrolide-resistant strains (22/30). Antagonism was not observed for any tested combination apart from clarithromycin with amoxicillin/clavulanic acid (22/100 isolates). Although the killing activities of all antibiotics improved when they were tested in combination, synergy was observed only for some combinations after 12 and/or 24 h. Serum concentrations were effective in inhibiting the growth of the tested strains. CONCLUSIONS: Combinations of levofloxacin with parenteral cephalosporins were the most active among all the tested combinations, while antagonism occurred when clarithromycin and amoxicillin/clavulanic acid were tested.

Modulation of biofilm of strains isolated from patients with chronic obstructive pulmonary disease by levofloxacin, moxifloxacin, ciprofloxacin, amoxicillin/clavulanic acid and ceftriaxone.

The ability of levofloxacin, moxifloxacin, ciprofloxacin, amoxicillin/clavulanic acid and ceftriaxone to interfere on biofilm produced by Pseudomonas aeruginosa, Haemophilus influenzae and Streptococcus pneumoniae isolated from patients with chronic obstructive pulmonary disease was evaluated. The effects of antibiotics were evaluated on formation of biofilm (at 1/2, 1/4 and 1/8 X MIC) and on preformed biofilm (at epithelial lining fluid peak concentrations) by means of a spectrophotometric method. Levofloxacin was the most active compound followed by ciprofloxacin, moxifloxacin and amoxicillin/clavulanic acid and ceftriaxone. Levofloxacin may contribute to clear the reservoir of pathogens involved in chronic obstructive pulmonary disease, thus leading to decreased occurrence of acute exacerbations.

Effects of Lactobacillus salivarius LS01 (DSM 22775) treatment on adult atopic dermatitis: a randomized placebo-controlled study.

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by xerosis, pruritus and eczema. The role of probiotics in the prevention and the treatment of AD have been extensively studied in children with controversial results while there are few studies on an adult population. The aim of this randomized, double-blind, placebo-controlled study is to evaluate the clinical efficacy of the intake of a probiotic strain (Lactobacillus salivarius LS01) in the treatment of adult patients with AD. A group of 38 patients was treated with probiotics or placebo (maltodextrin) for 16 weeks. The study was performed from January (T0) to May, 2009 (T16). The assessment of efficacy was based on change in SCORAD (SCORing Atopic Dermatitis) index, dermatology life quality index (DLQI) improvement, cytokine production by PBMCs and ability to modify faecal microbial flora. No significant adverse events were recorded during the study. Patients treated with probiotics showed a statistically improvement of both clinical parameters (SCORAD p<0.0001 and DLQI p= 0.021) at the end of treatment (T16) compared with the placebo group. Furthermore, after four months of treatment there was a significant reduction of Th1 cytokines (IL-12+IFNgamma) (p= 0.03) and Th1/Th2 ratio (IL-12+IFNgamma/IL-4+IL-5) (p= 0.019) only in placebo-treated patients. A statistically relevant decrease of staphylococci in faeces of the probiotictreated group was also observed at the end of treatment. In our study, the administration of L. salivarius LS01 was well tolerated and was associated with a significant improvement of clinical manifestation and QoL. This probiotic strain could have an important role in modulating Th1/Th2 cytokine profiles and could be considered as an important adjunctive therapy in the treatment of adult AD.

Microbiological evaluation of commercial probiotic products available in the USA in 2009.

Probiotics are widely used to prevent and treat several diseases. Many commercial products are available worldwide. However, there is no clear international or local legislation about them and previous studies showed that most of the tested products are not in conformity with international guidelines. The aim of this study was to determine if products available in the USA market in 2009 were correctly labeled in terms of quantity of viable bacteria, identification of species and cross contamination by species not on the label. Disturbingly, we found that only 4 of 13 products (31%) were in accordance with label claims. Our results suggest the need for adequate control of probiotic production as well as periodical screenings by competent organizations to monitor the effect of storage on product quality.

Should Lactobacillus sporogenes and Bacillus coagulans have a future?

Probiotics are gaining increasing scientific and commercial interest as functional foods. Their success has led to the development and marketing of a broad range of products based on probiotics. In this context, resolution of the taxonomy of microbial species remains a key point, since different species belonging to the same genus may have different beneficial properties. Lactobacillus sporogenes, which should be correctly classified as Bacillus coagulans, represents the archetypal misidentified probiotic and its inclusion among probiotics has often been a matter of debate. Since this bacterium shows characteristics of both genera Lactobacillus and Bacillus, its taxonomic position between the families lactobacillaceae and bacillaceae has often been discussed.This review summarizes the salient probiotic features of L. sporogenes /B. coagulans by examining currently available information. Although the use of L. sporogenes spores as a probiotic has increased in recent years, clinical evidence of its benefits are limited to only a few studies involving small patient populations.

In vitro selection of resistance in Streptococcus pneumoniae at in vivo fluoroquinolone concentrations.

OBJECTIVES: To compare the ability to select for resistance in Streptococcus pneumoniae of levofloxacin, moxifloxacin, ciprofloxacin and prulifloxacin. METHODS: Twenty strains of S. pneumoniae susceptible to fluoroquinolones were used. The frequencies of spontaneous single-step mutations at plasma and epithelial lining fluid (ELF) peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial subcultures on agar plates containing a linear gradient from peak to trough antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. Resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing gyrA, gyrB, parC and parE genes. RESULTS: Levofloxacin and moxifloxacin showed the lowest frequencies of mutations (median <10(-11)) at plasma peak and at ELF concentrations, while medians ranging from 10(-8) to 10(-6) were observed for ciprofloxacin and prulifloxacin. In a multi-step selection assay, ciprofloxacin and prulifloxacin selected for the highest number of resistant strains (19 and 31, respectively). No selection of resistance was observed for levofloxacin at ELF concentrations and for moxifloxacin at plasma and ELF concentrations. Mutations in parC, parE and gyrA genes were found in ciprofloxacin- and prulifloxacin-resistant strains, while only parC mutations were found for levofloxacin. CONCLUSIONS: Levofloxacin and moxifloxacin are characterized by a lower propensity to select in vitro for resistance in S. pneumoniae than ciprofloxacin and prulifloxacin, when tested at plasma and lung concentrations.

In vitro screening of probiotic characteristics of some italian products.

Six commercial probiotic products produced and marketed Italy (containing Lactobacillus GG, Lactobacillus casei DG, Lactobacillus reuteri, Bacillus clausii spores, Bifidobacterium longum and Saccharomyces boulardii) were assayed for their stability during storage, acid, base and bile tolerance and adherence to human intestinal cells. Results indicate that storage, even at conditions established by manufacturers, affects the microbial content of products based on B. longum and partially of that containing L. casei GG . Differences in acid and bile tolerance were found for the products, S. boulardii being better able to survive acid and bile than bacteria. Vegetative cells of B. clausii and B. longum were more susceptible than lactobacilli to low pH values, while fewer differences were found for bile tolerance. Lactobacilli and only partially B. longum, were able to adhere to Caco-2 cells, while S. boulardii and B. clausii showed reduced adherence to human intestinal cells. In conclusion, the products did not completely fulfill all probiotic attributes.