Long-term outcomes in patients with obesity and renal disease after sleeve gastrectomy.

Morbid obesity is a barrier to kidney transplant in patients with end-stage renal disease (ESRD). Laparoscopic sleeve gastrectomy (SG) is an increasingly considered intervention, but the safety and long-term outcomes are uncertain. We reviewed prospectively collected data on patients with ESRD and chronic kidney disease (CKD) undergoing SG from 2011 to 2018. There were 198 patients with ESRD and 45 patients with CKD (stages 1-4) who met National Institutes of Health guidelines for bariatric surgery and underwent SG; 72% and 48% achieved a body mass index of ≤ 40 and ≤ 35 kg/m2 , respectively. The mean percentages of total weight loss and excess weight loss were 18.9 ± 10.8% and 38.2 ± 20.3%, respectively. SG reduced hypertension (85.8% vs 52.1%), decreased antihypertensive medication use (1.6 vs 1.0) (P < .01 each), and reduced incidence of diabetes (59.6% vs 32.5%, P < .01). Of the 71 patients with ESRD who achieved a body mass index of ≤ 40 kg/m2 , 45 were waitlisted and received a kidney transplant, whereas 10 remain on the waitlist. Mortality rate after SG was 1.8 per 100 patient-years, compared with 7.3 for non-SG. Patients with stage 3a or 3b CKD exhibited improved glomerular filtration rate (43.5 vs 58.4 mL/min, P = .01). In conclusion, SG safely improves transplant candidacy while providing significant, sustainable effects on weight loss, reducing medical comorbidities, and possibly improving renal function in stage 3 patients.

Neutrophil derived microparticles increase mortality and the counter-inflammatory response in a murine model of sepsis.

Although advances in medical care have significantly improved sepsis survival, sepsis remains the leading cause of death in the ICU. This is likely due to a lack of complete understanding of the pathophysiologic mechanisms that lead to dysfunctional immunity. Neutrophil derived microparticles (NDMPs) have been shown to be the predominant microparticle present at infectious and inflamed foci in human models, however their effect on the immune response to inflammation and infection is sepsis has not been fully elucidated. As NDMPs may be a potential diagnostic and therapeutic target, we sought to determine the impact NDMPs on the immune response to a murine polymicrobial sepsis. We found that peritoneal neutrophil numbers, bacterial loads, and NDMPs were increased in our abdominal sepsis model. When NDMPs were injected into septic mice, we observed increased bacterial load, decreased neutrophil recruitment, increased expression of IL-10 and worsened mortality. Furthermore, the NDMPs express phosphatidylserine and are ingested by F4/80 macrophages via a Tim-4 and MFG-E8 dependent mechanism. Finally, upon treatment, NDMPs decrease macrophage activation, increase IL-10 release and decrease macrophage numbers. Altogether, these data suggest that NDMPs enhance immune dysfunction in sepsis by blunting the function of neutrophils and macrophages, two key cell populations involved in the early immune response to infection. This article is part of a Special Issue entitled: Immune and Metabolic Alterations in Trauma and Sepsis edited by Dr. Raghavan Raju.

Impact of caspase-8 and PKA in regulating neutrophil-derived microparticle generation.

The morbidity and mortality from sepsis continues to remain high despite extensive research into understanding this complex immunologic process. Further, while source control and antibiotic therapy have improved patient outcomes, many immunologically based therapies have fallen short. Microparticles (MPs) are intact vesicles that serve as mediators of intercellular communication as well as markers of inflammation in various disease processes. We have previously demonstrated that MPs can be produced at the infected foci during sepsis, are predominantly of neutrophil derivation (NDMPs) and can modulate immune cells. In this study, we sought to elucidate the molecular mechanisms underlying NDMP generation. Using thioglycolate (TGA) to recruit and activate neutrophils, we first determined that intra-peritoneal TGA increase NDMP accumulation. We next utilized TGA-elicited neutrophils in vitro to investigate signaling intermediates involved in NDMP production, including the intrinsic and extrinsic caspase pathways, cAMP dependent PKA and Epac activation as well as the role myosin light chain kinase (MLCK) as a final mediator of NDMP release. We observed that NDMP generation was dependent on the extrinsic caspase apoptotic pathway (caspase 3 and caspase 8), cAMP activation of PKA but not of Epac, and on activation of MLCK. Altogether, these data contribute to an overall framework depicting the molecular mechanisms that regulate NDMP generation.

Laparoscopic sigmoid colectomy: Are all laparoscopic techniques created equal?

BACKGROUND: Laparoscopic colectomy has been associated with improved postoperative pain control, earlier return to work, and shorter hospital stays compared to open colectomy. However, there are varied technical approaches to laparoscopic resections. We therefore sought to determine whether the straight laparoscopic approach was associated with shorter length of stay compared to hand-assisted and laparoscopic-assisted techniques for sigmoid colectomies. METHODS: A retrospective review of laparoscopic sigmoid colectomies performed by five colorectal surgeons from 2010 to 2014 was performed. Approaches were defined as: (1) straight laparoscopic if colon mobilization, inferior mesenteric artery transection and intra-corporeal anastomosis were performed laparoscopically, (2) hand assisted if a hand port was utilized to assist with mobilization and vessel transection, and (3) laparoscopic assisted if only the colon mobilization was performed intra-corporeally. Poisson regression was performed to determine the impact of surgical technique on LOS while controlling for differences in patient factors. RESULTS: A total of 191 patients were identified with 71 straight laparoscopic, 57 hand-assisted, and 63 laparoscopic-assisted cases. Substantial variability in choice of surgical technique was seen across surgeons. Patient populations were similar, with the exception of hand-assisted procedures being more often used in obese patients. Unadjusted average postoperative days to discharge were 3.6 days for straight laparoscopic and 4.1 and 4.0 days for hand-assisted and laparoscopic-assisted approaches, respectively. While controlling for factors associated with longer hospital stay, the straight laparoscopic approach was associated with a 14 % shorter stay compared to laparoscopic-assisted colectomy and a 15 % shorter stay compared to hand-assisted colectomy. The straight laparoscopic approach was also associated with earlier return of bowel function compared to other approaches. CONCLUSIONS: The straight laparoscopic approach to sigmoid colectomy is associated with substantially shorter postoperative stay and earlier return of bowel function when compared to hand-assisted and laparoscopic-assisted techniques. When technically feasible, the straight laparoscopic approach is preferred.

Postoperative predictors of early discharge following laparoscopic segmental colectomy.

PURPOSE: There is increasing pressure to shorten length of stay (LOS) after major surgical procedures. Although laparoscopic colectomy has been shown to have shorter LOS than open colectomy, not all patients experience a short length of stay. Predictive factors for early discharge after laparoscopic colectomy have not been clearly defined. We hypothesized that patients who exhibit a brisk urine output and lack of a systemic inflammatory response on the first postoperative day would experience a shorter postoperative stay after laparoscopic colectomy. METHODS: We performed a retrospective review of patients undergoing laparoscopic segmental colectomy by one of colorectal surgeons from 2012 to 2013. Patient demographics, operative characteristics, and postoperative factors were examined. A multiple linear regression model was used to examine the impact of various factors on length of stay, while controlling for confounding variables. Systemic inflammatory response syndrome (SIRS) was defined using Society of Critical Care Medicine consensus definitions. RESULTS: A total of 127 patients underwent a laparoscopic segmental colectomy. When controlling for confounding variables, ileus, postoperative complication, and SIRS response were associated with 2.67, 1.16, and 0.42 additional hospital days, respectively, while each additional liter of urine output on postoperative day 1 was associated with a 0.23-day decrease in LOS (p = 0.006). CONCLUSIONS: In the absence of postoperative ileus or overt complication, patients who do not exhibit a SIRS response, and have a brisk urine output on postoperative day (POD) 1, may be targeted for early hospital discharge after laparoscopic colectomy.

Novel betacoronavirus in dromedaries of the Middle East, 2013.

In 2013, a novel betacoronavirus was identified in fecal samples from dromedaries in Dubai, United Arab Emirates. Antibodies against the recombinant nucleocapsid protein of the virus, which we named dromedary camel coronavirus (DcCoV) UAE-HKU23, were detected in 52% of 59 dromedary serum samples tested. In an analysis of 3 complete DcCoV UAE-HKU23 genomes, we identified the virus as a betacoronavirus in lineage A1. The DcCoV UAE-HKU23 genome has G+C contents; a general preference for G/C in the third position of codons; a cleavage site for spike protein; and a membrane protein of similar length to that of other betacoronavirus A1 members, to which DcCoV UAE-HKU23 is phylogenetically closely related. Along with this coronavirus, viruses of at least 8 other families have been found to infect camels. Because camels have a close association with humans, continuous surveillance should be conducted to understand the potential for virus emergence in camels and for virus transmission to humans.

Obesity-induced hyperleptinemia improves survival and immune response in a murine model of sepsis.

BACKGROUND: Obesity is a growing health problem and associated with immune dysfunction. Sepsis is defined as systemic inflammatory response syndrome that occurs during infection. Excessive inflammation combined with immune dysfunction can lead to multiorgan damage and death. METHODS: The authors investigated the influence of a class 1 obesity (body mass index between 30 and 34.9) on immune function and outcome in sepsis and the role of leptin on the immune response. The authors used a long-term high-fat-diet feeding model (12 weeks) on C57Bl/6 mice (n = 100) and controls on standard diet (n = 140) followed by a polymicrobial sepsis induced by cecal ligation and puncture. RESULTS: The authors show that class 1 obesity is connected to significant higher serum leptin levels (data are mean ± SEM) (5.7 ± 1.2 vs. 2.7 ± 0.2 ng/ml; n = 5; P = 0.033) and improved innate immune response followed by significant better survival rate in sepsis (71.4%, n = 10 vs. 10%, n = 14; P < 0.0001). Additional sepsis-induced increases in leptin levels stabilize body temperature and are associated with a controlled immune response in a time-dependent and protective manner. Furthermore, leptin treatment of normal-weight septic mice with relative hypoleptinemia (n = 35) also significantly stabilizes body temperature, improves cellular immune response, and reduces proinflammatory cytokine response resulting in improved survival (30%; n = 10). CONCLUSIONS: Relative hyperleptinemia of class 1 obesity or induced by treatment is protective in sepsis. Leptin seems to play a regulatory role in the immune system in sepsis, and treatment of relative hypoleptinemia could offer a new way of an individual sepsis therapy.

Quantifying patient improvement following sacral neuromodulation: is it time for a new scoring system for fecal incontinence?

BACKGROUND: The Cleveland Clinic Florida Fecal Incontinence score is widely used to assess the severity of fecal incontinence. OBJECTIVE: We hypothesized that the Cleveland Clinic Fecal Florida Incontinence score is useful at establishing baseline disease severity, but it may underestimate the response to treatment following sacral neuromodulation because of the large number of patients who still wear a pad despite improved continence, as well as the inability to track improvements in urgency. DATA SOURCES: Data were obtained from prospectively maintained database of patients treated with sacral neuromodulation for fecal incontinence at 2 institutions beginning in 2011. DESIGN: A retrospective review of the individual components of Cleveland Clinic Fecal Florida Incontinence scores in response to treatment with sacral neuromodulation was performed. SETTINGS: The study was conducted at 1 academic medical center and 1 community medical center. PATIENTS: One hundred twenty-one consecutive patients were treated with sacral neuromodulation for fecal incontinence. INTERVENTIONS: No interventions occurred. MAIN OUTCOME MEASURES: Individual components of posttreatment Cleveland Clinic Florida Fecal Incontinence scores and subjective improvement in fecal urgency were the primary outcomes measured. RESULTS: The median preoperative Cleveland Clinic Fecal Florida Incontinence score of 14 decreased to 3 (interquartile range, 2-4) at 12 months. Of the patients, 66.1% reported still wearing a pad after the procedure. The reason for wearing a pad was residual fecal incontinence (41%), habit despite normal continence (35.3%), and urinary incontinence with complete fecal continence (23.5%). Of patients who report wearing a pad, 59% have falsely elevated Cleveland Clinic Fecal Florida Incontinence scores owing to wearing a pad despite complete fecal continence. Additionally, 96.3% of patients reported improvement in fecal urgency. LIMITATIONS: This retrospective study did not include a comparison with an alternative scoring system. CONCLUSIONS: Although the Cleveland Clinic Fecal Florida Incontinence score is a validated scale, which is simple to use for baseline disease severity, it may underestimate patient response to treatment. Additionally, it does not capture improvement in urgency. The ideal scoring system would be easy to use in clinical practice, and would account for improvement in fecal urgency.

Thymic stromal lymphopoietin mediates the host response and increases mortality during sepsis.

BACKGROUND: Sepsis and subsequent multiorgan system failure is associated with high rates of mortality and morbidity. Thymic stromal lymphopoietin (TSLP) is a cytokine that can be produced by keratinocytes and epithelial cells. Primarily, TSLP has been shown to promote counter-inflammatory processes. However, its potential expression or role in the pathogenesis of sepsis is largely unexplored. We hypothesized that TSLP is expressed during sepsis and TSLP blockade would alter the immune response and mortality. MATERIALS AND METHODS: Mice underwent cecal ligation and puncture (CLP) to produce a physiologically relevant murine model for sepsis. Cohorts were either treated with neutralizing TSLP antibodies or isotype controls before the CLP to determine changes in survival, bacterial loads, cytokine levels, and neutrophil function. RESULTS: It was observed that TSLP levels peaked at 6 h and remained detectable up to 48 h after CLP. Mice pretreated with neutralizing TSLP showed decreased mortality and bacterial load after CLP. Additionally, we determined that septic mice pretreated with the anti-TSLP antibody had increased tumor necrosis factor alpha and oxidative burst as well as increased interleukin 17 and neutrophil numbers compared with mice pretreated with isotype controls. CONCLUSIONS: TSLP levels peak early but are sustained during the first 48 h of sepsis. We speculate that TSLP blunts the neutrophil response resulting in increased bacterial load and mortality.

Assessing the immune status of critically ill trauma patients by flow cytometry.

BACKGROUND: Unintentional injury or trauma remains the leading cause of death among young adults. About one fifth of these trauma patients require care in an intensive care unit (ICU) because of severity of injuries and comorbidities. Patients hospitalized in an ICU are at increased risk for nosocomial infections, such as urinary tract infections, pneumonia, bacteremia, and wound infections. Many of these patients will develop sepsis or septic shock, and some will progress to multiple organ failure and death. The balance between the proinflammatory and counterinflammatory immune response appears to be a driving factor in this progression. At present, there is no proposed method for the timely detection of the immune status in trauma patients, making rational decisions to use immune-altering therapies difficult. OBJECTIVE: We demonstrate that flow cytometry, with its capabilities to characterize and/or enumerate (a) leukocyte subtypes, (b) leukocyte activation markers, (c) leukocyte-derived cytokines and microvesicles, and (d) leukocyte function is well suited to monitor the immune status of critically ill trauma patients. METHODS: Information for the review was obtained from the extant literature. DISCUSSION: We suggest that flow cytometry is a research method that might aid nurse scientists in investigating the immune status of critically ill patients, the recovery status of conditions such as hemorrhagic shock and tissue injury and the relationship between cancer disease progression and symptoms. Therefore, flow cytometry has the potential to broaden nursing research priority areas so that a comprehensive approach to understanding the cellular response is attained.

Mechanisms underlying mouse TNF-α stimulated neutrophil derived microparticle generation.

Despite advances in understanding and treatment of sepsis, it remains a disease with high mortality. Neutrophil Derived Microparticles (NDMPs) are present during sepsis and can modulate the immune system. As TNF-α is a cytokine that predominates in the initial stages of sepsis, we evaluated whether and how TNF-α can induce NDMPs in mice. We observed that TNF-α treatment results in increased NDMP numbers. We also determined that the activation of either TNF receptor 1 (TNFr1) or TNF receptor 2 (TNFr2) resulted in increased NDMP numbers and that activation of both resulted in an additive increase. Inhibition of Caspase 8 diminishes NDMPs generated through TNFr1 activation and inhibition of NF-κB abrogates NDMPs generated through activation of both TNFr1 and TNFr2. We conclude that the early production of TNF-α during sepsis can increase NDMP numbers through activation of the Caspase 8 pathway or NF-κB.

Natural Burkholderia mallei infection in Dromedary, Bahrain.

We confirm a natural infection of dromedaries with glanders. Multilocus variable number tandem repeat analysis of a Burkholderia mallei strain isolated from a diseased dromedary in Bahrain revealed close genetic proximity to strain Dubai 7, which caused an outbreak of glanders in horses in the United Arab Emirates in 2004.

Enhanced Recovery after Colorectal Surgery: Can We Afford Not to Use It?

BACKGROUND: Enhanced recovery pathways (ERPs) aim to reduce length of stay without adversely affecting short-term outcomes. High pharmaceutical costs associated with ERP regimens, however, remain a significant barrier to widespread implementation. We hypothesized that ERP would reduce hospital costs after elective colorectal resections, despite the use of more expensive pharmaceutical agents. STUDY DESIGN: An ERP was implemented in January 2016 at our institution. We collected data on consecutive colorectal resections for 1 year before adoption of ERP (traditional, n = 160) and compared them with consecutive resections after universal adoption of ERP (n = 146). Short-term surgical outcomes, total direct costs, and direct hospital pharmacy costs were compared between patients who received the ERP and those who did not. RESULTS: After implementation of the ERP, median length of stay decreased from 5.0 to 3.0 days (p < 0.01). There were no differences in 30-day complications (8.1% vs 8.9%) or hospital readmission (11.9% vs 11.0%). The ERP patients required significantly less narcotics during their index hospitalization (211.7 vs 720.2 morphine equivalence units; p < 0.01) and tolerated a regular diet 1 day sooner (p < 0.01). Despite a higher daily pharmacy cost ($477 per day vs $318 per day in the traditional cohort), the total direct pharmacy cost for the hospitalization was reduced in ERP patients ($1,534 vs $1,859; p = 0.016). Total direct cost was also lower in ERP patients ($9,791 vs $11,508; p = 0.004). CONCLUSIONS: Implementation of an ERP for patients undergoing elective colorectal resection substantially reduced length of stay, total hospital cost, and direct pharmacy cost without increasing complications or readmission rates. Enhanced recovery pathway after colorectal resection has both clinical and financial benefits. Widespread implementation has the potential for a dramatic impact on healthcare costs.

Amitriptyline Usage Exacerbates the Immune Suppression Following Burn Injury.

Currently, over 10% of the US population is taking antidepressants. Numerous antidepressants such as amitriptyline are known to inhibit acid sphingomyelinase (Asm), an enzyme that is known to mediate leukocyte function and homeostasis. Severe burn injury can lead to an immunosuppressive state that is characterized by decreased leukocyte function and numbers as well as increased susceptibility to infection. Based upon the intersection of these facts, we hypothesized that amitriptyline-treated, scald-injured mice would have an altered immune response to injury as compared with untreated scald mice. Prior to burn, mice were pretreated with amitriptyline. Drug- or saline-treated mice were subjected full thickness dorsal scald- or sham-injury. Immune cells from spleen, thymus, and bone marrow were subsequently harvested and characterized. We first observed that amitriptyline prior to burn injury increased body mass loss and spleen contraction. Both amitriptylinetreatment and burn injury resulted in a 40% decrease of leukocyte Asm activity. Following scald injury, we demonstrate increased reduction of lymphocyte precursors in the bone marrow and thymus, as well as mature leukocytes in the spleen in mice that were treated with amitriptyline. We also demonstrate that amitriptyline treatment prior to injury reduced neutrophil accumulation following peptidoglycan stimulus in scald-injured mice. These data show that Asm alterations can play a significant role in mediating alterations to the immune system after injury. The data further suggest that those taking antidepressants may be at a higher risk for complications following burn injury.

Is sacral neuromodulation here to stay? Clinical outcomes of a new treatment for fecal incontinence.

INTRODUCTION: Sacral neuromodulation (SNM) was approved by the FDA for the treatment of fecal incontinence (FI) in 2011, and previous industry-sponsored trials have shown excellent clinical outcomes. The purpose of this study is to examine clinical outcomes of patients treated during our initial experience with SNM. METHODS: A prospective database of patients treated with SNM for FI by one of three colorectal surgeons at two separate institutions was maintained starting in 2011. Patients showing ≥50% improvement of weekly incontinent episodes during test stimulation were offered permanent implantation of the SNM device. Disease severity was tracked using the Wexner score. RESULTS: A total of 145 patients received a full system implantation (of 152 who received test stimulation). The median preoperative Wexner score of 14 decreased to 3, 3 months after implantation and persisted to 12 months. At 12 months, 95.2% of patients achieved >50% improvement in Wexner Score and 67.6% achieved >75% improvement. The most common adverse event was infection (3.4%). Three patients (2.1%) required lead revision. CONCLUSIONS: SNM is a safe and effective therapy for the treatment of FI. Postoperative patient surveillance is important, as many patients require programming changes, and some will require a lead revision over time.

Neutrophil derived microvesicles: emerging role of a key mediator to the immune response.

In response to infection and trauma, exquisite control of the innate inflammatory response is necessary to promote an anti-microbial response and minimize tissue injury. Over the course of the host response, activated leukocytes are essential for the initial response and can later become unresponsive or undergo apoptosis. Leukocytes, along the continuum of activation to apoptosis, have been shown to generate microvesicles. These vesicles can range in size from 0.1 to 1.0 µm and can retain proteins, RNA and DNA of their parent cells. Importantly, neutrophil-derived microvesicles (NDMV) are robustly increased under inflammatory conditions. The aim of this review is to summarize the research to date upon NDMVs. This will include describing under which disease states NDMVs are increased, mechanisms underlying formation, and the impact of these vesicles upon cellular targets. Altogether, increased awareness of NDMVs during the host innate response may allow for diagnostic tools as well as potential novel therapies during infection and trauma.

Characterization of microparticles after hepatic ischemia-reperfusion injury.

BACKGROUND: Hepatic ischemia-reperfusion (I/R) is a well-studied model of liver injury and has demonstrated a biphasic injury followed by recovery and regeneration. Microparticles (MPs) are a developing field of study and these small membrane bound vesicles have been shown to have effector function in other physiologic and pathologic states. This study was designed to quantify the levels of MPs from various cell origins-platelets, neutrophils, and endolethial cells-following hepatic ischemia-reperfusion injury. METHODS: A murine model was used with mice undergoing 90 minutes of partial hepatic ischemia followed by various times of reperfusion. Following reperfusion, plasma samples were taken and MPs of various cell origins were labeled and levels were measured using flow cytometry. Additionally, cell specific MPs were further assessed by Annexin V, which stains for the presence of phosphatidylserine, a cell surface marker linked to apoptosis. Statistical analysis was performed using one-way analysis of variance with subsequent Student-Newman-Keuls test with data presented as the mean and standard error of the mean. RESULTS: MPs from varying sources show an increase in circulating levels following hepatic I/R injury. However, the timing of the appearance of different MP subtypes differs for each cell type. Platelet and neutrophil-derived MP levels demonstrated an acute elevation following injury whereas endothelial-derived MP levels demonstrated a delayed elevation. CONCLUSION: This is the first study to characterize circulating levels of cell-specific MPs after hepatic I/R injury and suggests that MPs derived from platelets and neutrophils serve as markers of inflammatory injury and may be active participants in this process. In contrast, MPs derived from endothelial cells increase after the injury response during the reparative phase and may be important in angiogenesis that occurs in the regenerating liver.

Genotyping of Burkholderia mallei from an outbreak of glanders in Bahrain suggests multiple introduction events.

BACKGROUND: Glanders, caused by the gram-negative bacterium Burkholderia mallei, is a highly infectious zoonotic disease of solipeds causing severe disease in animals and men. Although eradicated from many Western countries, it recently emerged in Asia, the Middle-East, Africa, and South America. Due to its rareness, little is known about outbreak dynamics of the disease and its epidemiology. METHODOLOGY/PRINCIPAL FINDINGS: We investigated a recent outbreak of glanders in Bahrain by applying high resolution genotyping (multiple locus variable number of tandem repeats, MLVA) and comparative whole genome sequencing to B. mallei isolated from infected horses and a camel. These results were compared to samples obtained from an outbreak in the United Arab Emirates in 2004, and further placed into a broader phylogeographic context based on previously published B. mallei data. The samples from the outbreak in Bahrain separated into two distinct clusters, suggesting a complex epidemiological background and evidence for the involvement of multiple B. mallei strains. Additionally, the samples from Bahrain were more closely related to B. mallei isolated from horses in the United Arab Emirates in 2004 than other B. mallei which is suggestive of repeated importation to the region from similar geographic sources. CONCLUSION/SIGNIFICANCE: High-resolution genotyping and comparative whole genome analysis revealed the same phylogenetic patterns among our samples. The close relationship of the Dubai/UAE B. mallei populations to each other may be indicative of a similar geographic origin that has yet to be identified for the infecting strains. The recent emergence of glanders in combination with worldwide horse trading might pose a new risk for human infections.

Microarray-based genotyping of Staphylococcus aureus isolates from camels.

Staphylococcus aureus is a common cause of mastitis and other diseases in camels. In order to obtain data on population structure as well as on the carriage of toxin genes and resistance markers, a collection of 45 isolates from dromedaries of Dubai, United Arab Emirates, were genotyped. These isolates belonged to clonal complexes CC6 (twenty isolates; 44.44%), CC30 (sixteen isolates; 35.56%), CC188 (five isolates; 11.11%), CC152 (1 isolate, 2.2%) and to a previously un-described sequence type (ST1755: arcc-18, aroe-115, glpf-6, gmk-2 pta-109, tpi-50 and yqil-2; three isolates; 6.67%). Resistance genes proved to be rare. Only three out of 45 isolates (6.67%) carried the beta-lactamase operon. The tetracycline resistance gene tetK was also detected in three isolates (6.67%). Neither the mecA gene, defining MRSA, nor other resistance genes were found. Common virulence markers included leukocidin genes lukD+lukE (in twenty-five isolates; 55.56%), the staphylokinase gene sak (twenty-two isolates; 48.89%), the enterotoxin gene cluster egc (fifteen isolates; 33.33%), and a distinct variant of the enterotoxin A gene (sea-320E, GenBank AY196686.1; thirteen isolates; 28.89%). One CC152 isolate was positive for genes encoding the Panton-Valentine leukocidin (lukF-PV+lukS-PV). This study provides first genotyping data on the population structure and the presence of toxin genes and resistance markers of S. aureus strains in Middle Eastern camels.