Operative management of isolated posterior cruciate ligament injuries improves stability and reduces the incidence of secondary osteoarthritis: a systematic review.

PURPOSE: To evaluate the evidence for operative and non-operative management of isolated posterior cruciate ligament (PCL) injuries. METHODS: Using Pubmed, EMBASE and Cochrane databases, a systematic review was conducted of studies investigating the treatment of isolated PCL injuries published until July 2020. Quality assessment was performed with the Cochrane risk of bias tool (level I), the Newcastle-Ottowa Scale (level II-III) and the National Institute of Health quality assessment tool (level IV). Clinical outcome measures included residual laxity, return to sports, patient-reported outcome measures, subsequent articular degeneration and complications. RESULTS: Twenty-seven studies [23 case series, 2 case-control, 1 cohort study and 1 randomized controlled trial (RCT)] including 5197 patients (5199 knees) with a mean age of 29.5 ± 3.6 years (range 15-68) fulfilled the study requirements. Significantly less residual laxity was found after posterior cruciate ligament reconstruction (PCLR) compared to non-operative management (3.43 vs. 5.47 mm, CI: 1.84-2.23, p < 0.001). Both treatment modalities yielded satisfying functional outcomes and a high return to sports (64-77%, mean: 70.3, CI: 67.8-72.2). Osteoarthritis (OA) occurred less frequently following PCLR (21.5 vs. 44.1%, p < 0.001). CONCLUSION: In the absence of level I RCTs, this systematic review suggests that surgical management for selected isolated PCL injuries is a reasonable option to consider, especially when the surgeon aims at minimizing residual laxity and presumably secondary osteoarthritis. LEVEL OF EVIDENCE: IV.

How small modifications in laboratory workflow of blood cultures can have a significant impact on time to results.

Rapid identification and antimicrobial susceptibility testing of micro-organisms causing bloodstream infections is crucial in the management of septic patients. In this study, we compared a period of twice-daily and a period of thrice-daily reading of subculture agar plates. In 2016, 10,644 positive blood cultures bottles (bioMérieux) from 2608 patients were analyzed at UZ Leuven. Identification and antimicrobial susceptibility testing were performed by MALDI-TOF MS (Bruker Daltonics) and Vitek 2 (bioMérieux) respectively. In period 1 (January to June), subculture plates were read at 8:30 a.m. and 2:00 p.m. during the weekdays. In period 2 (August until December), reading was performed at 8:30 a.m., 2:00 p.m., and 5:00 p.m. Time to identification and time to AST results after positivity were compared. In period 1, median time to identification of all organisms was 22.8 h compared to 20.2 h in period 2 (p < 0.01). Moreover, micro-organisms were identified before 12 h in 9% of samples in period 2, a significant increase compared to 2% in period 1 (p < 0.01). In period 2, AST results were known within 36 h in 39% of samples, compared to 31% in period 1 (p < 0.01). Optimization of the reading frequency of subcultures of blood cultures significantly decreases time to results. Further optimization can be done by introducing lab automation. We will use the data of this study as a baseline to analyze the impact of introducing WASPLab (Copan Diagnostics) automation on time to results.

Performance of three generations of Xpert MRSA in routine practice: approaching the aim?

The aim of this study was to evaluate retrospectively the performance of the Xpert MRSA assay in routine practice and its current use in the intensive care unit (ICU) setting of our hospital, since a pre-emptive isolation strategy has been applied. A total of 6473 patients were routinely screened with ESwab for methicillin-resistant Staphylococcus aureus (MRSA) using three generations of rapid real-time polymerase chain reaction (PCR) (Cepheid GeneXpert) over three consecutive periods of time. Performance was evaluated using broth enrichment culture as the reference method. Our results show that the last generation of Xpert MRSA (NxG) assay is more specific (99.2% vs. 97.9%) but not more sensitive (77.8% vs. 86.9%) than the third generation. Considering the low prevalence of MRSA in our hospital, we obtained an overall low positive predictive value. In conclusion, it remains difficult to abandon the reference method in routine practice considering the possible implications of an erroneous MRSA result in the ICU.

Characterisation of Staphylococcus aureus isolates from bloodstream infections, Democratic Republic of the Congo.

Staphylococcus aureus is known worldwide as an invasive pathogen, but information on S. aureus from bloodstream infections in Central Africa remains scarce. A collection of S. aureus blood culture isolates recovered from hospitals in four provinces in the Democratic Republic of the Congo (2009-2013) was assessed. A total of 27/108 isolates were methicillin-resistant S. aureus (MRSA), of which >70% were co-resistant to aminoglycosides, tetracyclines, macrolides and lincosamides. For MRSA and methicillin-susceptible S. aureus (MSSA) isolates, resistance to chloramphenicol and trimethoprim-sulphamethoxazole (TMP-SMX) was <10%. However, 66.7% (72/108) of all isolates harboured the trimethoprim resistance gene dfrG. More than three-quarters (84/108, 77.8%) of isolates belonged to CC5, CC8, CC121 or CC152. Genetic diversity was higher among MSSA (31 spa types) compared to MRSA (four spa types). Most MRSA (23/27, 85.2%) belonged to CC8-spa t1476-SCCmec V and 17/23 (73.9%) MRSA ST8 were oxacillin susceptible but cefoxitin resistant. Among MRSA and MSSA combined, 49.1% (53/108) and 19.4% (21/108) contained the genes encoding for Panton-Valentine leucocidin (lukS-lukF PV, PVL) and toxic shock syndrome toxin-1 (tst, TSST-1), respectively. PVL was mainly detected among MSSA (51/53 isolates harbouring PVL were MSSA, 96.2%) and associated with CC121, CC152, CC1 and CC5. TSST-1 was associated with CC8-spa t1476-SCCmec V. The immune evasion cluster (IEC) genes scn, sak and chp were detected in 81.5% of isolates (88/108, equally represented among MSSA and MRSA). The present study confirms the occurrence of MRSA with high levels of multidrug co-resistance and PVL-positive MSSA among invasive S. aureus isolates in Central Africa.

Binary toxin and its clinical importance in Clostridium difficile infection, Belgium.

Binary toxin-producing Clostridium difficile strains such as ribotypes 027 and 078 have been associated with increased Clostridium difficile infection (CDI) severity. Our objective was to investigate the association between presence of the binary toxin gene and CDI severity and recurrence. We performed a laboratory-based retrospective study including patients between January 2013 and March 2015 whose fecal samples were analyzed by polymerase chain reaction (PCR) for the presence of the genes for toxin B and binary toxin and a deletion in the tcdC gene, specific for ribotype 027. Clinical and epidemiological characteristics were compared between 33 binary toxin-positive CDI patients and 33 binary toxin-negative CDI patients. Subsequently, the characteristics of 66 CDI patients were compared to those of 66 diarrhea patients who were carriers of non-toxigenic C. difficile strains. Fifty-nine of 1034 (5.7 %) fecal samples analyzed by PCR were binary toxin-positive, belonging to 33 different patients. No samples were positive for ribotype 027. Binary toxin-positive CDI patients did not differ from binary toxin-negative CDI patients in terms of disease recurrence, morbidity, or mortality, except for a higher peripheral leukocytosis in the binary toxin-positive group (16.30 × 109/L vs. 11.65 × 109/L; p = 0.02). The second part of our study showed that CDI patients had more severe disease, but not a higher 30-day mortality rate than diarrhea patients with a non-toxicogenic C. difficile strain. In our setting with a low prevalence of ribotype 027, the presence of the binary toxin gene is not associated with poor outcome.

A large community outbreak of gastroenteritis associated with consumption of drinking water contaminated by river water, Belgium, 2010.

SUMMARY On 6 December 2010 a fire in Hemiksem, Belgium, was extinguished by the fire brigade with both river water and tap water. Local physicians were asked to report all cases of gastroenteritis. We conducted a retrospective cohort study among 1000 randomly selected households. We performed a statistical and geospatial analysis. Human stool samples, tap water and river water were tested for pathogens. Of the 1185 persons living in the 528 responding households, 222 (18·7%) reported symptoms of gastroenteritis during the time period 6-13 December. Drinking tap water was significantly associated with an increased risk for gastroenteritis (relative risk 3·67, 95% confidence interval 2·86-4·70) as was place of residence. Campylobacter sp. (2/56), norovirus GI and GII (11/56), rotavirus (1/56) and Giardia lamblia (3/56) were detected in stool samples. Tap water samples tested positive for faecal indicator bacteria and protozoa. The results support the hypothesis that a point-source contamination of the tap water with river water was the cause of the multi-pathogen waterborne outbreak.

Epidemiology and outcome of invasive pneumococcal disease among adults in Belgium, 2009-2011.

This epidemiological study examined morbidity and case fatality of invasive pneumococcal disease (IPD) in adults in Belgium as well as distribution and antibiotic susceptibility of Streptococcus pneumoniae serotypes.Adults hospitalised with microbiologically proven IPD were prospectively enrolled. The study started in 2009 with patients aged ≥50 years, whereas in 2010 and 2011, patients aged ≥18 years were included. The clinical presentation, patient profile, treatment, outcome, and mortality were recorded during hospitalisation.Outcome was also assessed one month afterdischarge. Of the 1,875 patients with IPD identified, 1,332 were included in the analysis. Bacteraemic pneumonia, affecting 1,049 of the patients, was the most frequent IPD type (79%), and chronic obstructive pulmonary disease and cancer were the main comorbidities.One-third of patients required admission to intensive care unit. A total of 208 (16%) patients died during hospitalisation and an additional 21 (2%) within one month after discharge. Case fatality rates of ≥20%were observed in patients with chronic heart failure, hepatic disease, and renal insufficiency. Serotypes 7F, 1, 19A, and 3 were the most prevalent and together accounted for 47% (569/1,214) of all IPD cases and 42% (80/189) of mortality. Of the patient isolates, 21% (255/1,204) were resistant to erythromycin and 22% (264/1,204) to tetracycline. Penicillin non-susceptibility was mostly found in serotype 19A isolates. These baseline data are essential when assessing the impact of pneumococcal conjugate vaccination in adults in the future.

Comparison of different phenotypic assays for the detection of extended-spectrum ß-lactamase production by inducible AmpC-producing Gram-negative bacilli.

Routine detection of extended-spectrum ß-lactamase (ESBL) production by AmpC-producing Enterobacteriaceae in microbiology laboratories is still a problem. The aim of this study was to compare the performance of four different phenotypic ESBL confirmation assays within this group of Enterobacteriaceae. A total of 83 AmpC-inducible Enterobacteriaceae were included in this study (58 clinical isolates with presumptive ESBL production and 25 molecularly characterized ESBL-producing isolates). Each isolate was tested for the presence of an ESBL enzyme by four phenotypic ESBL confirmation assays: ESBL Etests and combined double-disk synergy tests (CDDST), both on Mueller-Hinton (MH) agar with and without the use of cloxacillin, an AmpC inhibitor. Our study showed that performing a CDDST on MH agar with cefotaxime as the only indicator cephalosporin is not a reliable way to detect ESBL-encoding genes among chromosomal AmpC-producing Enterobacteriaceae due to its low sensitivity (52 %). The use of cloxacillin in this CDDST could only significantly increase the specificity of the CDDST when used with ceftazidime as the indicator [sensitivity (SN), 92 %; specificity (SP), 93 %]. Regarding ESBL Etest® strips, the sensitivity of the cefepime strip (80 %) was significantly higher compared to the cefotaxime and ceftazidime strips (16 % and 32 %, respectively). Adding cloxacillin to the MH agar improved the ESBL detection of each of these strips. We recommend the CDDST on MH agar supplemented with cloxacillin and ceftazidime or cefepime as the indicator cephalosporin as the most cost-efficient strategy to confirm ESBL production in inducible AmpC-producing Enterobacteriaceae.

Antimicrobial resistance to benzylpenicillin in invasive pneumococcal disease in Belgium, 2003-2010: the effect of altering clinical breakpoints.

The Belgian data (2003-2010) for the European Antimicrobial Resistance Surveillance Network (EARS-Net) showed a significant decreasing trend in the proportion of penicillin non-susceptible Streptococcus pneumoniae (9·4% to <1%) from blood and CSF isolates. We found that 75% of this decrease was explained by a change in Clinical and Laboratory Standards Institute (CLSI) breakpoints as the trend disappeared if only the new breakpoints were applied. Applying only European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints also resulted in a relatively stable proportion of penicillin non-susceptibility (average 5%), but this proportion was 7-13 times higher than with the new CLSI breakpoints. When the new CLSI breakpoints alone are used, fewer than 1% of bacteraemia isolates were penicillin non-susceptible during the entire period, but the proportion of non-susceptible meningitis isolates rose from 6·3% in 2003 to 15·9% between 2003 and 2010. Changing breakpoints should lead to retrospective analysis of historical data to minimize wrongly interpreting resistance trends.

High incidence of bloodstream infection detected by surveillance blood cultures in hematology patients on corticosteroid therapy.

PURPOSE: The aim of our study was to evaluate the frequency of "occult" bacteremia/fungemia as well as the diversity of pathogens involved in hematology patients treated with corticosteroids. METHODS: Daily surveillance blood cultures were taken from patients treated with corticosteroids as part of their intensive chemotherapy or during graft-versus-host disease following hematopoietic stem cell transplantation during a 3-year period (2006-2009). We reviewed the frequency of occult bacteremia/fungemia as well as the pathogens involved. RESULTS: During the 3-year period, 3,821 bottles were cultured from 215 patients and 4.9 % of the bottles tested were positive. Surveillance blood cultures revealed bloodstream infection in 24 % of the patients (definite bloodstream infection in 16 %). Seventy-five percent of patients were still afebrile when microorganisms were detected. The main risk group was acute lymphocytic leukemia patients undergoing remission induction chemotherapy. The pathogens cultured most frequently were coagulase-negative staphylococci, enterococci, Escherichia coli, and Pseudomonas aeruginosa. CONCLUSIONS: A high incidence of occult bacteremia was detected by surveillance blood cultures. Further studies are needed to evaluate if a strategy based on surveillance blood cultures can reduce mortality related to bloodstream infections.

Clinical evaluation of the Copan ESwab for methicillin-resistant Staphylococcus aureus detection and culture of wounds.

The screening for and diagnosis of bacteriological infections often involves the collection and transportation of swab samples. The Copan ESwab was compared with the dry cotton Copan swab for methicillin-resistant Staphylococcus aureus (MRSA) screening (n = 200 paired samples) and with the Amies agar gel swab (Copan) for the sampling of burn and orthopaedic wounds (n = 203 paired samples) in terms of Gram staining and bacterial recovery. Gram stains performed with ESwab liquid showed significantly more Gram-negative rods, streptococci, Gram-positive cocci, Gram-positive rods, polymorphonuclear cells, lymphocytes and red blood cells than Gram stains from dry swabs. Bacterial recovery was significantly higher with ESwab (p < 0.01, for both MRSA screening and wounds, quantitative/semi-quantitative method). This lead to a slightly higher detection rate of MRSA (128 vs. 124 MRSA-positive ESwabs and dry swabs, respectively, p = 0.50) and a higher detection rate of coagulase-negative Staphylococcus spp. (44 isolates with ESwab vs. 29 with Amies gel swab, p = 0.001) and Enterococcus spp. (15 isolates with ESwab vs. 7 isolates with Amies gel swab, p = 0.005) with ESwab (quantitative method). We confirmed that ESwab has a high performance for Gram stains and a higher bacterial recovery than dry and Amies gel swabs when using clinical samples for MRSA screening and wound sampling.

Breakthrough Saprochaete capitata infections in patients receiving echinocandins: case report and review of the literature.

We report a rare case of a fatal Saprochaete capitata breakthrough infection in a patient with acute myeloid leukemia receiving empirical caspofungin therapy. S. capitata is an uncommon, yet emerging cause of invasive infections, especially in patients with haematological malignancies. Blood cultures from our patient yielded S. capitata which was found to be resistant, in vitro, to caspofungin. We consecutively reviewed all published cases of breakthrough infections caused by S. capitata in patients receiving echinocandins. S. capitata should be considered in those patients who remain febrile or who develop invasive mould infections while under echinocandin therapy.

Bacteraemia caused by Leptotrichia trevisanii in a neutropenic patient.

We describe an episode of Leptotrichia trevisanii bacteraemia in a neutropenic hemato-oncology patient receiving chemotherapy for Refractory Anemia with Excess Blasts-2 (RAEB-2). Although Leptotrichia spp. colonize the oral cavity and genitourinary tract, serious episodes of bacteraemia might occur in immunocompromised patients, particularly in those with severe neutropenia. Therefore, microbiologists should consider the possibility of Leptotrichia spp. septicemia in patients with blood cultures positive for gram negative bacilli, when routine microbiology tests fail to reveal a correct identification of the organism.

10th survey of antimicrobial resistance in noninvasive clinical isolates of Streptococcus pneumoniae collected in Belgium during winter 2007-2008.

OBJECTIVES: The aim of the study was to evaluate the antibiotic resistance in noninvasive clinical isolates of Streptococcus pneumoniae collected in Belgium during winter 2008-2007. METHOD: Four hundred and forty eight unduplicated isolates collected by 15 laboratories were tested by microdilution following CLSI. RESULTS: Insusceptibility rates (I+R) were as follows: penicillin G (PEN) 11.6% (4.0% R), ampicillin 11.4% (4.0% R), amoxicillin+/-clavulanic acid 0, cefaclor 10.3% (9.6% R), cefuroxime 9.2% (8.7% R), cefuroxime-axetil 8.7% (7.8% R), cefotaxime, ceftazidime and cefepime 2.0% (0% R), imipenem 2.5% (0% R), ciprofloxacin and ofloxacin 5.1% (0.4% R), levofloxacin 0.7% (0.4% R), moxifloxacin 0.4% (0.2% R), erythromycin (ERY) 29.7% (29.2% R), azithromycin 29.7% (28.8% R), telithromycin 0%, clindamycin 26.3% (25.4% R) and tetracycline (TET) 21.9% (16.5% R). From 2001 to 2008, a significant decrease in penicillin-insusceptibility (21.0% to 11.6%), penicillin-resistance (9.7% to 4.0%) and ciprofloxacin-insusceptibility (11.2% to 5.1%) was found. Cross-resistance between penicillin and other betalactams in penicillin-insusceptible isolates was incomplete: all these isolates remained fully susceptible to amoxicillin. Erythromycin-insusceptibility was significantly higher in children than in adults (43.9%/27.4%), while penicillin-insusceptibility significantly higher in Brussels than in the Flanders (22.9%/8.1%). The commonest resistance phenotype was ERY-TET (12.7%) followed by ERY (7.4%) and PEN-ERY-TET (5.8%). Capsular types 19 (25%), 14 (19.3%), 23 (15.4%) and 15 (13.5%) were the most important in penicillin-insusceptible. CONCLUSION: We noted a decrease in resistance to the majority of the compounds. Insusceptibility rates were higher in children than in adults and the difference between the north and the south of Belgium became less marked.

Preoperative eye disinfection in vitrectomy surgery using antibiotic or antiseptic eyedrops.

PURPOSE: To determine the efficacy of preoperative eye disinfection by comparing antibiotic and antiseptic eye drops. DESIGN: Prospective, randomized double-masked comparative study with three study arms: untreated, antibiotic treated and antiseptic treated. METHODS: Patients that were scheduled for vitrectomy were asked to use an antibiotic or antiseptic eye drop 4 times a day, 5 days before the surgery. Conjunctival smear was cultured at the onset of the surgery. Culture results for each study arm were compared. RESULTS: Comparable results were found in the patients treated with an antibiotic or antiseptic eye drop. CONCLUSIONS: Since an antiseptic eye drop will cause less bacterial resistance than an antibiotic eye drop, and both treatments have a similar antibacterial effect, this study indicates that prophylactic antiseptic eye drops may be preferred over antibiotic treatment, when prophylaxis is needed.

Influence of postmortem time on the outcome of blood cultures among cadaveric tissue donors.

Tissue banks provide tissues of human cadaver donors for transplantation. The maximal time limit for tissue retrieval has been set at 24 h postmortem. This study aimed at evaluating the evidence for this limit from a microbiological point of view. The delay of growth in postmortem blood cultures, the identification of the species isolated and clinical/environmental factors were investigated among 100 potential tissue donors. No significant difference was found in the rate of donors with grown blood cultures within (25/65=38%) compared with after (24/65=37%) 24 h of death. Coagulase-negative staphylococci and gastro-intestinal microorganisms were isolated within and after 24 h of death. Two factors--antimicrobial therapy and "delay before body cooling"--were significantly inversely related with donors' blood culture results. From a microbiological point of view, there is no evidence for avoiding tissue retrieval among donors after 24 h of death.

Effectiveness of antibiotics and antiseptics on coagulase-negative staphylococci for the decontamination of bone allografts.

Bone allografts retrieved from multi-organ donors can be decontaminated with minimally aggressive methods. Therefore, we evaluated the efficacy of antibiotics and antiseptics in the decontamination of bone fragments actively contaminated with coagulase-negative staphylococci. Gentamicin (512/1,024 microg/mL), rifampicin (400/1,000 microg/mL), chlorhexidine in alcohol and chlorhexidine soap were tested with different contact times and temperatures and a delay in starting decontamination. Gentamicin-susceptible strains dried on bone could be removed by gentamicin 512 microg/mL after 19 h of contact, while strains not dried on bone could be eliminated by soaking bone for 60 min in gentamicin 512 microg/mL. Rifampicin-susceptible strains could be eliminated by soaking bone for 60 min in rifampicin 1,000 microg/mL. In none of the experimental conditions could gentamicin/rifampicin-resistant staphylococci be eliminated. Antiseptics could not eliminate staphylococci from bone. Different antibiotics need different protocols in order to decontaminate bone allografts.

Antibacterial 5'-O-(N-dipeptidyl)-sulfamoyladenosines.

The aminoacyl-tRNA synthetase (aaRS) class of enzymes is a validated target for antimicrobial development. Aminoacyl analogues of 5'-O-(N-L-aminoacyl)-sulfamoyladenosines are known to be potent inhibitors of aaRS, but whole cell antibacterial activity of these compounds is very limited, and poor penetration into bacteria has been proposed as the main reason for this. Aiming to find derivatives that better penetrate bacteria, we developed a simple and short method to prepare dipeptidyl-derivatives of 5'-O-(N-L-aminoacyl)-sulfamoyladenosines, and used this method to prepare 18 5'-O-(N-dipeptidyl)-sulfamoyladenosines. The antibacterial activity of these derivatives and a number of reference compounds against S. aureus, E. faecalis and E. coli was determined. Several of the new derivatives showed improved antibacterial activity and an altered spectrum of antibacterial activity.

An outbreak of peritonitis caused by multidrug-resistant Salmonella Typhi in Kinshasa, Democratic Republic of Congo.

Between October 2004 and January 2005, 144 patients with peritonitis were admitted to the surgical wards of Kinshasa General Hospital and a few private city clinics. 63 patients (44%) underwent surgical intervention because of intestinal perforation consistent with typhoid fever; the case fatality rate was 53%. The majority of patients had received a course of first-line antibiotics such as chloramphenicol, ampicillin or co-trimoxazole before admission. On bacteriological investigation, Salmonella Typhi was isolated from the blood of 11 patients with peritonitis. The isolates were all resistant to ampicillin, chloramphenicol, tetracycline and co-trimoxazole, but sensitive to third-generation cephalosporins, quinolone (nalidixic acid, ciprofloxacine) and amoxicillin-clavulanic acid. Several factors contributed to the poor outcome of this disease including a) the use of inappropriate antibiotics, b) long delay in diagnosis, c) difficult access to health facilities. This is the first documented outbreak of typhoid fever caused by a multidrug-resistant S. Typhi in Kinshasa.

Bacteriostasis testing on allograft tissue inoculated in Wilkins-Chalgren broth.

Tissue banks culture tissue specimens to confirm the absence of viable micro-organisms after decontamination with antibiotics. It is possible that antibiotic residues attached to decontaminated tissue are introduced into enrichment culture media. These could have an inhibitory effect on the culture results and generate false-negative results. Our aim was to detect bacteriostasis in Wilkins-Chalgren broth inoculated with bone and tendon remnants. These remnants had been soaked in a solution containing gentamicin as part of the tissue-processing procedure. We used the United States Pharmacopeia method for bacteriostasis testing with gentamicin-susceptible Pseudomonas aeruginosa American Type Culture Collection (ATCC) 15442, Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633 as test strains, and gentamicin-resistant Candida albicans ATCC 90029 as control. The residual gentamicin concentration in the broths was determined and gentamicin-soaked tissue was placed on Mueller-Hinton agar inoculated with a staphylococcal suspension. Bacteriostasis was present in 53-75% of the reference test strains. Tendon remnants had a significantly higher rate of bacteriostasis (85%) than bone remnants (28%). Broths inoculated with tendon remnants had the highest residual gentamicin concentrations.