High-dose Gentamicin Research Articles

Bactericidal effect of gentamicin conjugated gold nanoparticles

The authors explored the antibacterial activity of gentamicin conjugated gold nanoparticles against Escherichia coli bacteria by using the disk diffusion method. Gold nanoparticles were prepared by the reduction of tetrachloroauric acid with sodium citrate. Experiments were performed with relatively lower and higher doses of gentamicin, gold nanoparticles, and gentamicin conjugated gold nanoparticles. Atomic force microscopy (AFM) images of the bacterial colonies with and without treatment were taken. Results show that gentamicin used alone in a lower range of doses did not cause any growth inhibition, but when used in conjugation with gold nanoparticles, clear inhibition zones were visible. The ratios of inhibition areas of gold nanoparticles with gentamicin to only gentamicin were more in case of bigger sized gold nanoparticles. AFM images of the bacterial colonies also showed that gentamicin conjugated gold nanoparticles were more effective than other groups in inhibiting bacterial growth.

Identifying innate immune receptors causing production of inflammatory cytokines by infection of Francisella tularensis

Abstract Francisella tularensis is a pathogenic species and a causative agent of tularemia. This bacterium is incredibly infectious and often lethal in that F. tularensis causes the overproduction of pro-inflammatory cytokines. The objective of this study is to identify the innate immune receptors responsible for the production of inflammatory cytokines in response to F. tularensis infection. The study uses an immortalized C57BL/6 Bone Marrow Macrophage (BMMac) cell line as the control and knockout BMMac that are deficient in various innate immune receptors. The cells are passaged and seeded before infecting them with F. tularensis for 2 hours. The cells are treated with a high dose of gentamicin for 2 hours followed by a low dose of gentamicin for an incubation period of 24 hours. The supernatant from these cells are then collected and analysis processed by ELISA, an enzyme-linked immunosorbent assay, to measure production of inflammatory cytokines. These data were compared with the positive control of wild type BMMac and the negative control of uninfected BMMac cells. Analysis of these mutants reveal the involvement of innate immune receptors in triggering the pro-inflammatory cytokine storm in response to F. tularensis infection that leads to death of the host.

Neutrophil Gelatinase-associated Lipocalin (NGAL) a Promising Biomarker for Early Detection of Nephrotoxic Injury

Renal toxic injury can neither be predicted nor quantified exactly by the serum creatinine level. NGAL is a promising biomarker for early detection of AKI due to different causes. Our objective was to evaluate it�s value in the setting of nephrotoxic injury. We performed an experiment in which we administered gentamicin, atropine and fipronil at different doses to the laboratory mice to quantify the evolution of creatinine and NGAL. Compared to creatinine, NGAL increased faster and was detected at elevated levels from the first 4 h after administration of both low and high dose gentamicin. Fipronil, atropine and the combination caused a significant increase in NGAL serum values at 4 hours, an increase that lasted up to 24 and 72 h , respectively, compared to the control group, Its highest levels were recorded at 4 h. Compared to creatinine, NGAL increased faster and was detected at elevated levels from the first 4 h after administration of fipronil, atropine and the combination of them.

Hearing in Schoolchildren After Neonatal Exposure to a High-Dose Gentamicin Regimen.

To assess the association between gentamicin exposure in the neonatal period and hearing in school age. This study included children exposed to a high-dose (6 mg/kg) gentamicin regimen as neonates (2004-2012), invited for follow-up at school age, and a healthy age-matched control group. We assessed hearing with pure tone audiometry including the extended high-frequency (EHF) range. Outcomes were average hearing thresholds in the midfrequencies (0.5-4 kHz) and the EHFs (9-16 kHz). The measures of gentamicin exposure were cumulative dose and highest trough plasma concentration. We used linear regression models to assess the impact of gentamicin exposure, and other peri- and postnatal morbidities, on hearing thresholds. A total of 219 gentamicin-exposed and 33 healthy-control children were included in the audiological analysis. In the gentamicin cohort, 39 (17%) had a birth weight <1500 g. Median cumulative doses and trough plasma concentrations were 30 (interquartile range 24-42) mg/kg and 1.0 (interquartile range 0.7-1.2) mg/L, respectively. Median hearing thresholds for the midfrequencies and the EHFs were 2.5 (0 to 6.3) dB hearing level and -1.7 (-5.0 to 5.0) dB hearing level, both of which were within the normal range. In an adjusted analysis, increasing hearing thresholds were associated with lower birth weight and postnatal middle-ear disease but not level of gentamicin exposure. After adjusting for birth weight, there was no difference in hearing threshold between the gentamicin-exposed cohort and healthy controls. Exposure to a high-dose gentamicin regimen in the neonatal period was not associated with an increase in hearing thresholds in schoolchildren being able to complete audiometry.

High dose of vancomycin plus gentamicin incorporated acrylic bone cement decreased the elution of vancomycin.

PurposeLow doses of vancomycin and gentamicin were commonly incorporated into acrylic bone cement (antibiotic-impregnated bone cement, AIBC) during revision arthroplasty. Previous studies showed that only a very small amount of antibiotics could be eluted from AIBC. Given the fact that a high dose of antibiotic would elute high concentration of antibiotic, this study investigated the influence of a high dose of dual-antibiotic loading on the properties of cement.MethodsA total of 8 groups of AIBC containing either gentamicin or vancomycin or both with different amounts of antibiotics (1 g, 2 g and 4 g) were tested on material properties, elution profiles, antibacterial activity and cytological toxicity.ResultsA high dose of gentamicin and vancomycin AIBC (with 2 g gentamicin and 2 g vancomycin loaded) regiment showed acceptable compressive strength of 74.25±0.72 MPa. No cytotoxicity or antibacterial activity reduction was observed in any group tested in this study. The elution profiles indicated that incorporating 2 g vancomycin resulted in 4.77% (1049.57±3.74 μg) released after 28 days. However, after 2 g gentamicin was added, the vancomycin released was significantly reduced to 2.42% (532.24±1.77 μg) (p<0.001), approximately 50% reduction. No significant influence of vancomycin on gentamicin was observed.ConclusionThese findings suggest that the addition of 2 g vancomycin and 2 g gentamicin into acrylic bone cement was preferred while considering this dual-antibiotic AIBC regiment with acceptably material properties and effective antibacterial activity. However, special attention should be drawn to the reduction of vancomycin elution when incorporated with gentamicin.

Standard-dose gentamicin does not increase risk of patent ductus arteriosus

BackgroundRates of patent ductus arteriosus (PDA) and infection are high in preterm infants. Preterm infants with infection are more likely to develop symptomatic PDA, a potentially fatal disease. Clinically, gentamicin is widely used for early-onset infection in neonates including preterm infants. A recent study demonstrated that standard-dose gentamicin itself, not infection, increased risk of PDA in mice, suggesting that gentamicin should be avoided in neonates with a risk of PDA. This claim has been insufficiently investigated in subsequent in-vivo experiments. We reevaluated the in-vivo effect of standard-dose gentamicin on patency of the rat ductus arteriosus (DA). Methods1) To evaluate the effect of gentamicin on DA patency duration, gentamicin was intraperitoneally injected immediately after birth. 2) To evaluate the effect of gentamicin on DA reopening, gentamicin was intraperitoneally injected 30 min after birth. In both scenarios, 30 min after gentamicin administration, rapid whole-body freezing was performed and the inner diameter of the DA was measured. ResultsStandard-dose gentamicin (5 μg/g) did not prolong patency of the DA or increase the likelihood of DA reopening in rat neonates. High-dose gentamicin (100 μg/g), however, significantly prolonged patency of the DA and was associated with DA reopening in rat neonates, although the dilative effect did not reach statistical significance. ConclusionStandard-dose gentamicin does not increase the risk of PDA in rat neonates. This study suggests that standard-dose gentamicin can be used to treat infection in neonates without increasing PDA morbidity.

Improving peak concentrations of a single dose regime of gentamicin in patients with sepsis in the emergency department

ObjectiveTo achieve an optimal effect in patients with sepsis at the emergency department (ED), the gentamicin peak-concentration should be sufficiently high (i.e. peak-concentration/MIC ≥8–10). ICU patients with sepsis often need higher gentamicin doses to achieve sufficiently high peak-concentrations. The aim of this study is to investigate which dose is needed to reach adequate peak-concentrations in patients presenting with sepsis at the ED.MethodsPatients with sepsis at the ED were included from August 2015 until February 2017. Peak-concentrations were measured in blood 30 minutes after the first gentamicin dose. The study consisted of three phases. In the first phase, peak-concentrations were measured after a standard dose of 5mg/kg. In the second phase, a simulation ((peak-concentration/actual dose) × simulated dose) was performed to determine which dose was needed to reach adequate gentamicin peak-concentrations of ≥16mg/L. In the third phase, peak-concentrations were measured for the best simulated dose.ResultsIn phase one, of 86 patients who received a dose of 5mg/kg, 34 (39.5%) patients did not reach the target peak-concentration of ≥16mg/L, and 73 (84.9%) did not reach ≥20mg/L. In phase two, the simulation showed that with a dose of 7mg/kg 83 (96.5%) patients would reach peak-concentrations ≥16mg/L, and 67 (77.9%) of ≥20mg/L. In phase three, 53 patients received a dose of 7mg/kg, of whom 45 (84.9%) reached peak-concentrations of ≥16mg/L, and 31 (58.5%) of ≥20mg/L.ConclusionPatients with sepsis at the ED need higher doses of gentamicin. A dose of 7mg/kg is needed to achieve adequate peak-concentrations in the majority of patients.

Listeria monocytogenes switches from dissemination to persistence by adopting a vacuolar lifestyle in epithelial cells.

Listeria monocytogenes causes listeriosis, a foodborne disease that poses serious risks to fetuses, newborns and immunocompromised adults. This intracellular bacterial pathogen proliferates in the host cytosol and exploits the host actin polymerization machinery to spread from cell-to-cell and disseminate in the host. Here, we report that during several days of infection in human hepatocytes or trophoblast cells, L. monocytogenes switches from this active motile lifestyle to a stage of persistence in vacuoles. Upon intercellular spread, bacteria gradually stopped producing the actin-nucleating protein ActA and became trapped in lysosome-like vacuoles termed Listeria-Containing Vacuoles (LisCVs). Subpopulations of bacteria resisted degradation in LisCVs and entered a slow/non-replicative state. During the subculture of host cells harboring LisCVs, bacteria showed a capacity to cycle between the vacuolar and the actin-based motility stages. When ActA was absent, such as in ΔactA mutants, vacuolar bacteria parasitized host cells in the so-called “viable but non-culturable” state (VBNC), preventing their detection by conventional colony counting methods. The exposure of infected cells to high doses of gentamicin did not trigger the formation of LisCVs, but selected for vacuolar and VBNC bacteria. Together, these results reveal the ability of L. monocytogenes to enter a persistent state in a subset of epithelial cells, which may favor the asymptomatic carriage of this pathogen, lengthen the incubation period of listeriosis, and promote bacterial survival during antibiotic therapy.

An Antioxidant Screen Identifies Candidates for Protection of Cochlear Hair Cells from Gentamicin Toxicity.

Reactive oxygen species are important elements in ototoxic damage to hair cells (HCs), appearing early in the damage process. Higher levels of natural antioxidants are positively correlated with resistance to ototoxins and many studies have shown that exogenous antioxidants can protect HCs from damage. While a very wide variety of antioxidants with different characteristics and intracellular targets exist, most ototoxicity studies have focused upon one or a few well-characterized compounds. Relatively little research has attempted to determine the comparative efficacy of large variety of different antioxidants. This has been in part due to the lack of translation between cell culture and in vivo measures of efficacy. To circumvent this limitation, we used an in vitro assay based on micro-explants from the basal and middle turns of the neonatal mouse organ of Corti to screen a commercial redox library of diverse antioxidant compounds for their ability to protect mammalian HCs from a high dose of the ototoxic antibiotic gentamicin. The library included several antioxidants that have previously been studied as potential treatments for HC damage, as well as many antioxidants that have never been applied to ototoxicity. The micro-explants were treated with 200 μM gentamicin alone, gentamicin plus one of three dosages of a redox compound, the highest dosage of compound alone, or were untreated. HC counts were determined before the gentamicin insult and at 1, 2, and 3 days afterward to evaluate the HC survival. From a total of 81 antioxidant compounds, 13 exhibited significant protection of HCs. These included members of a variety of antioxidant classes with several novel antioxidants, not previously tested on HCs, appearing to alleviate the damaging gentamicin effect. Some compounds previously shown to be protective of HCs were correspondingly protective in this in vitro screen, while others were not. Finally, one of the three pro-oxidant compounds included in the library as well as six antioxidants exhibited evidence of toxicity in the absence of gentamicin. The results demonstrate the wide variability in the ability of antioxidants to protect HCs from high-dose gentamicin damage, and identify promising candidate leads for further study as potential drug targets.Highlights• A medium-throughput assay based on micro-explants of the organ of Corti was developed to screen mammalian cochlear hair cells for protection from damage by ototoxins.• Eighty one antioxidants and 3 pro-oxidants were evaluated for hair cell protection from high-dose gentamicin.• Thirteen antioxidants were significantly protective, while 6 proved to be damaging.• The use of a common assay permitted an evaluation of the relative capacity of different antioxidants for the protection of hair cells.

Experience With Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses

BackgroundGentamicin has been determined to be active against a wide range of bacterial infections and has been commonly used as a preoperative antibiotic for inflatable penile prosthesis (IPP) implantation. However, the best dosing regimen to produce the safest optimal prophylactic effect remains to be determined. AimTo compare low- and high-dose gentamicin as prophylaxis during IPP implantation. MethodsWe retrospectively analyzed two groups of patients who underwent IPP placement from April 14, 2012 through April 13, 2016. Group 1 was composed of 490 patients who underwent IPP placement from April 14, 2012 through April 13, 2014 and received a low dose of preoperative gentamicin at 80 mg every 8 hours for 1 day. Group 2 was composed of 407 patients who underwent IPP placement from April 14, 2014 through April 13, 2016 and received a single high dose of preoperative gentamicin at 5 mg/kg. We compared the infection rates of IPP and any gentamicin-related toxicities. The same surgeon performed all procedures. All patients received additional vancomycin 1 g before incision and at 12 hours postoperatively. OutcomeDemographic data and IPP infection rate were compared and potential toxicities from the higher dose of gentamicin were closely monitored. ResultsThere were no significant differences in mean age, mean body mass index, and mean interval for IPP placement and IPP infection between the two groups. No toxicity was seen with the higher gentamicin dose. Six cases in group 1 (five de novo cases and one redo case, infection rate = 1.22%) and three cases in group 2 (two de novo cases and one redo case, infection rate = 0.74%) were found to have IPP infection. The infection rate in group 2 appeared to be lower than that in group 1, although a significant statistical difference was not achieved (P = .057). Clinical ImplicationsThese findings would help guide urologists in choosing an optimal preoperative gentamicin dose for IPP surgery. Strengths and LimitationsThis is the first study to report on the usage of high-dose preoperative gentamicin for IPP surgery but with limitations as a retrospective study. ConclusionsAlthough not achieving a statistical difference, there was a trend for patients receiving a higher dose of preoperative gentamicin to have a lower IPP infection rate. No toxicity was encountered from the 5-mg/kg gentamicin dose. We recommend following prophylactic high-dose gentamicin guidelines.Xie D, Gheiler V, Lopez I, et al. Experience With Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses. J Sex Med 2017;14:1160–1164.

198 A Retrospective Analysis of the Influence of High Dose Gentamicin on IPP Infection Rates

198 A Retrospective Analysis of the Influence of High Dose Gentamicin on IPP Infection Rates

234 A Retrospective Analysis of the Influence of High Dose Gentamicin on IPP Infection Rates

234 A Retrospective Analysis of the Influence of High Dose Gentamicin on IPP Infection Rates

Efficacy of antimicrobial lock solutions in preventing catheter-related blood stream infection in haemodialysis patients: a systematic review and meta-analysis of prospective randomised controlled trials

Background: Catheter-related blood stream infection (CRBSI) contributes to morbidity and mortality among patients on haemodialysis (HD). We carried out a systematic review and meta-analysis to assess the efficacy of antimicrobial lock solutions (ALS) in preventing CRBSI.Method: Electronic search of randomised controlled trials (RCTs) comparing ALS with other agents was performed up to January 2013. DerSimonian and Laird meta-analysis was performed to obtain pooled relative risk (RR) from which efficacy of ALS and numbers needed to treat (NNT) were calculated. In a restricted analysis, pooled RRs where compared using a test of interaction to calculate ratio of relative risks (RRR). Meta-regression analysis was employed to explore sources of heterogeneity.Results: Sixteen RCTs involving 2016 individuals met the inclusion criteria. The efficacy of ALS in preventing CRBSI was 80% with NNT of 3 patients to prevent one CRBSI. The RR of CRBSI was significantly lower with ALS compared with heparin-only lock solution [RR {95% confidence interval (CI)} = 0.20 (0.13-0.31)]. With low dose (≤ 5 mg/ml) and high dose (40 mg/ ml) gentamicin-containing ALS, the RR (95% CI) of developing CRBSI was 0.03 (0.01-0.13) and 0.18 (0.03-0.98), respectively, with no significant difference [RRR (95% CI) = 0.2 (0.02-1.61), p = 0.126]. Heterogeneity was explained by a statistically significant association between rate of CRBSI and catheter days (p = 0.037). Conclusion: ALS are effective in preventing CRBSI. Low dose gentamicin should be preferred over high dose gentamicin as an ALS because it offers similar benefit in preventing CRBSI with lesser risk of toxicity from systemic leakage and subsequent development of drug resistance.

A study to evaluate the first dose of gentamicin needed to achieve a peak plasma concentration of 30mg/l in patients hospitalized for severe sepsis.

Previous studies have shown that the high dose of gentamicin (8mg/kg) rarely achieves the desired peak plasma concentration (Cmax) of ≥30mg/l in patients with severe sepsis or septic shock. The aim of this study was to determine the first dose of gentamicin needed to achieve a Cmax ≥ 30mg/l. We conducted a prospective observational cohort study in one intensive care unit. All consecutive patients hospitalized for severe sepsis or septic shock and treated with a first dose of gentamicin >6mg/kg were evaluated. During the study period, 15 of the 57 patients (26.3%) treated with gentamicin had a Cmax ≥ 30mg/l. The median dose of gentamicin administered was 8.9 [7.8-9.9] mg/kg. Independent factors in the multivariate analysis associated with a Cmax ≥ 30mg/l were higher body mass index (per kg/m(2) increment) (OR: 1.173, 95%CI: 1.015-1.356, P = 0.03) and higher first dose of gentamicin (per mg/kg increment) (OR: 2.343, 95%CI: 1.346-4.08, P = 0.003). The optimal first dose to achieve a Cmax ≥ 30mg/l was 11mg/kg, with a specificity and a sensitivity of 100% and 53.3% respectively. These results suggest that a first dose of gentamicin >11mg/kg is needed to achieve a Cmax ≥ 30mg/l in most patients.

Single high dose gentamicin for perioperative prophylaxis in orthopedic surgery: Evaluation of nephrotoxicity

Background:Recent studies described an increase in acute kidney injury when high dose gentamicin was included in perioperative prophylaxis for orthopedic surgeries. To this effect, we compared the rate of nephrotoxicity for selected orthopedic surgeries where gentamicin was included (Gentamicin Group) to those where it was not included (Control Group) for perioperative prophylaxis and evaluated risk factors for nephrotoxicity.Methods:Spine, hip and knee surgeries performed between April 2011 and December 2013 were reviewed retrospectively. Gentamicin was given to eligible patients based on age, weight and Creatinine Clearance. Nephrotoxicity was assessed using Risk, Injury, Failure, Loss, End-stage kidney disease (RIFLE) criteria.Results:Among selected surgeries (N = 1590 in Gentamicin Group: hip = 926, spine = 600, knee = 64; N = 2587 in Control Group: hip = 980, spine = 902, knee = 705), patients’ body weight, serum creatinine, comorbidities and surgery duration were similar in Gentamicin Group and Control Group. Gentamicin median dose was 4.5 mg/kg of dosing weight. Nephrotoxicity rate was 2.5% in Gentamicin Group and 1.8% in Control Group, p = 0.17. Most cases of nephrotoxicity were Risk category by RIFLE criteria (67% in Gentamicin Group and 72% in Control Group, p = 0.49). In logistic regression, risk factors for nephrotoxicity were hospital stay >1 day prior to surgery (odds ratio = 8.1; 95% confidence interval = 2.25–28.97, p = 0.001), knee or hip surgery (odds ratio = 4.7; 95% confidence interval = 2.9–9.48, p = 0.0005) and diabetes (odds ratio = 1.95; 95% confidence interval = 1.13–3.35, p = 0.016). Receipt of gentamicin was not an independent predictor of nephrotoxicity (odds ratio = 1.5; 95% confidence interval = 0.97–2.35, p = 0.07).Conclusion:In this cohort, rate of nephrotoxicity was similar between Gentamicin Group and Control Group. Single high dose gentamicin is a safe and acceptable option for perioperative prophylaxis in eligible patients undergoing orthopedic surgeries.

Expanded Gram-Negative Antimicrobial Prophylaxis Reduces Surgical Site Infections in Hip Arthroplasty

BackgroundA first-generation cephalosporin is the recommended antibiotic prophylaxis for implants. However, this standard does not address the increasing prevalence and virulence of gram-negative pathogens infecting patients. We found that gram-negative bacilli caused 30% of our surgical site infections (SSIs) following hip procedures, whereas only 10% of knee SSIs were caused by gram-negative bacilli. To address this, we instituted Expanded Gram-Negative Antimicrobial Prophylaxis (EGNAP) for our hip arthroplasty patients. The purpose of this study is to measure the effect of EGNAP on the SSI rates following primary total hip arthroplasty. MethodsThe study consisted of 10,084 total patients. Before July 2012, all patients were administered 1 g of cefazolin. After July 2012, our protocol was adjusted by adding the EGNAP with either gentamicin or aztreonam to hip patients (group 1) and not to the knee arthroplasty patients (group 2). ResultsGroup 1 consisted of the 5389 primary hip arthroplasty patients. Of these patients, 4122 (before July 2012) did not receive weight-based high-dose gentamicin and 1267 (after July 2012) did. Before the introduction of EGNAP, group 1 SSI rate was 1.19% (49/4122). After July 2012 when EGNAP was added, the overall group 1 SSI rate decreased to 0.55% (7/1267) (P = .05). During the study period, there was not a significant difference in SSI rate of knee arthroplasty (group 2): 1.08% vs 1.02% (P = .999). ConclusionsThe addition of EGNAP for hip arthroplasty is a safe and effective method to decrease SSIs.Level of Evidence: III. Case-control study.

Gentamicin arrests cancer cell growth: the intriguing involvement of nuclear sphingomyelin metabolism.

The use of gentamicin for the treatment of bacterial infection has always been an interesting and highly speculated issue for the scientific community. Conversely, its effect on cancer cells has been very little investigated. We studied the effect of high doses of gentamicin on non-Hodgkin’s T-cell human lymphoblastic lymphoma (SUP-T1). We showed that gentamicin delayed cell growth and induced cell death in lymphoma cells with a rather mild effect on lymphocytes. In SUP-T1 cells, GAPDH, B2M, CDKN1A and CDKN1B were down-expressed in comparison with lymphocytes. Gentamicin treatment in SUP-T1 cells restored the expression of GAPDH, B2M and CDKN1A to values similar to those of lymphocytes and caused overexpression of CDKN1B. The drug acted via sphingomyelin metabolism; in whole cells, sphingomyelinase activity was stimulated, whereas in purified nuclei, sphingomyelinase activity was inhibited and that of sphingomyelin-synthase was stimulated, with a consequent high level of nuclear sphingomyelin content. We suggest that the increase of nuclear sphingomyelin might enrich the nucleus of lipid microdomains that act as a platform for active chromatin and, thus, might be responsible for gene expression. It is possible that in lymphoblastic lymphoma, high doses of gentamicin induce a beneficial therapeutic outcome.

Assessment of mitochondrial membrane potential in HEI-OC1 and LLC-PK1 cells treated with gentamicin and mitoquinone.

To determine the effects of concurrent treatment with gentamicin and the mitochondria-targeted antioxidant mitoquinone (MitoQ; which may prevent gentamicin ototoxicity) on change in the mitochondrial membrane potential (Δψ(m)), a precursor of apoptosis. Prospective and controlled. Academic research laboratory. LLC-PK1 (Lilly Laboratories Culture-Pig Kidney Type 1) and HEI-OC1 (House Ear Institute Organ of Corti 1) cells-renal and auditory cell lines, respectively-were used in this study. Δψ(m) was assessed by flow cytometry through the MitoProbe JC-1 Kit for Flow Cytometry in untreated LLC-PK1 and HEI-OC1 cells and cells exposed to low- (100µM) or high- (2000µM) dose gentamicin for 24 hours, with and without 0.5µM each of MitoQ or idebenone (IDB; an untargeted ubiquinone). Δψ(m) was not different in untreated LLC-PK1 cells and cells coincubated with low-dose gentamicin and MitoQ or IDB (P > .05). In HEI-OC1 cells, coincubation with low-dose gentamicin and MitoQ decreased Δψ(m) (P = .002). Coincubation of LLC-PK1 cells with high-dose gentamicin and DMSO, MitoQ, or IDB depolarized Δψ(m) (P < .0001), with MitoQ depolarizing the Δψ(m) to a greater extent than that of IDB (P = .03). In contrast, HEI-OC1 cells demonstrated a hyperpolarized Δψ(m) when coincubated with high-dose gentamicin and DMSO, MitoQ, or IDB (P < .001). The combination of gentamicin and MitoQ holds the potential to disrupt Δψ(m). This suggests a heightened need to monitor for toxicity in patients receiving both agents.

Assessment of Mitochondrial Function and Membrane Potential in PK1 Cells Treated with Gentamicin and MitoQ

Objectives: Determine the effects of concurrent treatment with the aminoglycoside antibiotic gentamicin and mitoquinone (MitoQ), a mitochondria-targeted derivative of the antioxidant ubiquinone that may protect against aminoglycoside ototoxicity, on mitochondrial function and membrane potential. Methods: This study was prospective and controlled. Mitochondrial membrane potential (MMP) was assessed by flow cytometry using MitoProbeTM JC-1 Kit in untreated PK1 cells and cells exposed to low (100 µM) or high (2000 µM) dose gentamicin for 24 hours, with and without 0.5 µM each of MitoQ or idebenone (an untargeted ubiquinone). Mitochondrial function was determined using the Seahorse XF-24TM flux analyzer. Results: MMP was not different in untreated cells and cells co-incubated with low-dose gentamicin and MitoQ or idebenone ( P &gt; .05). Co-incubation with high-dose gentamicin and MitoQ or idebenone decreased MMP ( P &lt; .0001), with MitoQ co-incubation decreasing MMP to a greater extent compared with idebenone ( P = .0001). Basal oxygen consumption rate (OCR) was not different between treatments ( P = .15). Maximal OCR was not different between untreated cells and cells treated with MitoQ alone, low dose gentamicin alone, or the combination of MitoQ and low dose gentamicin ( P &gt; .05). In contrast, cells treated with high dose gentamicin and in combination with MitoQ have reduced maximal OCR ( P = .037 and .026). Conclusions: The combination of gentamicin and MitoQ holds the potential to disrupt mitochondrial function and membrane potential. This suggests a heightened need to monitor for toxicity in patients receiving both agents.

Toxic Anterior Segment Syndrome following Phacoemulsification Secondary to Overdose of Intracameral Gentamicin.

Objective. To report a case of toxic anterior segment syndrome (TASS) that was caused by inadvertent anterior chamber and cornea stromal injection with high dose gentamicin following cataract surgery. Methods. Case report. Results. We report a 72-year-old female patient who developed TASS that was caused by high dose gentamicin (20 mg/0.5 mL), which was inadvertently used during the formation of the anterior chamber and hydration of the corneal incision. Unlike previous cases, hyphema and hemorrhagic fibrinous reaction were seen in the anterior chamber. Despite treatment, bullous keratopathy developed and penetrating keratoplasty was performed. The excised corneal button was sent for histopathological examination. Conclusions. Subconjunctival gentamicin is highly toxic to the corneal endothelium and anterior chamber structures. Including it on the surgical table carries a potentially serious risk for contamination of the anterior chamber.