Presence Of Multidrug-resistant Bacteria Research Articles

Mobile Phone Contamination in Clinical Environments ‘The True Extent’

Smart phones are integral , especially within healthcare. However, there are increasing concerns regarding their contamination and potential infection control risk. Bacteria under selective pressure can rapidly acquire resistant mechanisms leading to the assumption; mobile phones used within clinical environment may harbour bacteria associated with a higher infection mortality rate. Using next generation sequencing technology, characterise the true extent of bacterial contamination on mobile phones of hospital staff and determine the presence of multi-drug resistant bacteria associated with hospital acquired infections. DNA was extracted from the swab tips of 450 Particpant’s mobile phones. 16S rRNA primers were used to characterise and compare the microbiome on devices from the hospital staff and a control group. Staphylococcus aureus and Enterococcus faecalis underwent Kirby Baur disc diffusion. Results The microbiome revealed the extent of contamination far exceeds anything previously reported. In particular, gram-negative bacteria (including several important potential pathogens) were grossly under detected. 198 bacteria genus were discovered on mobile phones of which 34 were unique to the hospital. Differences were also detected between hospital departments. MRSA, VRSA and VRE were only detected within the hospital group. Our results indicate traditional culture-dependent swabbing methods don’t provide an accurate account of mobile phone contamination. This may also be true in other areas relevant to infection control. Used within clinical environments could expose patients to unknown levels of multi drug resistant bacteria. Decontamination between patient contact should be a necessity to prevent the undermining of hand hygiene and the transmission of MDR bacteria.

Cervical vertebral osteomyelitis secondary to Streptococcus equi infection in an adult horse - case report

ABSTRACT A 15-year-old, mixed breed, male horse was attended with a history of multiple abscesses in the cervical region with a three-year evolution. Upon admission, three fistulous tracts with drainage of purulent secretions in the cervical region, low body score, restriction of cervical movements, and painful sensitivity to palpation were observed. The horse was diagnosed with osteomyelitis secondary to Streptococcus equi infection. The initial treatment was antibiotic therapy and local curative. Owing to the lack of response, surgical debridement was performed. An initial favorable response was observed; however, after 4 months, drainage recurred, and the animal was euthanized. A post-mortem computed tomography scan was performed to obtain details of the injury. Cervical osteomyelitis is rare, and its occurrence through hematogenous spread in adult horses and the tomographic findings had not been reported previously. The long period of evolution, difficulty in performing an aggressive debridement, and the presence of multi-drug resistant bacteria contributed to the negative outcome.

Multidrug-Resistant Bacteria and Disease Progression in Patients with End-Stage Liver Disease and after Liver Transplantation

Multidrug-resistant (MDR) pathogens represent an emerging challenge in end-stage liver disease and in liver transplant recipients. We evaluated the impact of MDR bacteria upon clinical outcomes in patients with end-stage liver disease (n = 777) at the time of enrollment on the liver transplant (LTx) waiting list, after first LTx (n = 645), and after second LTx (n = 128). Colonization/infection with MDR bacteria was present in 72/777 patients on the waiting list, in 98/645 patients at first LTx, and in 46/128 patients at second LTx. While on the LTx waiting list, the time until first hydropic decompensation (p = 0.021), hepatic encephalopathy (p < 0.001) and hepatorenal syndrome (p < 0.001) was reduced in the presence of MDR bacteria, which remained an independent risk factor of poor survival in multivariate analysis (p < 0.001). Following first and second liver transplant, MDR bacteria were associated with an increased risk of infection-related deaths (first LTx: p < 0.001; second LTx: p = 0.037) and reduced actuarial survival (first LTx: p < 0.001; second LTx: p = 0.046). We showed that MDR pathogens are associated with poor outcomes before, after first and after recurrent LTx.

Assessment of Antibiotic Levels, Multi-Drug Resistant Bacteria and Genetic Biomarkers in the Waters of the Rio Grande River Between the United States-Mexico Border.

Background.The worldwide emergence of multi-drug resistant bacteria has become a health crisis, as fewer or sometimes no antimicrobial agents are effective against these bacteria. The Rio Grande River is the natural boundary between the United States (US) and Mexico. It spans a border region between Texas, New Mexico and Mexico. Underserved populations on the Mexican side use the river for recreational purposes, while on the US side, the river is used for irrigation and as a source of drinking water.Objectives.The purpose of the present study was to evaluate the concentration of antibiotic residues, to determine the presence of genetic elements conferring antibiotic resistance and to characterize multi-drug resistant bacteria in the waters of the Rio Grande River.Methods.Water samples were obtained from the Rio Grande River. Deoxyribonucleic acid (DNA) was extracted from both isolated bacteria and directly from the water. Amplification of selected genetic elements was accomplished by polymerase chain reaction. Identification and isolation of bacteria was performed through MicroScan autoSCAN-4. Fecal contamination was assessed by IDEXX Colilert. Antibiotic residues were determined by liquid chromatography and mass spectrometry.Results.Antibiotics were found in 92% of both water and sediment samples. Antibiotic concentrations ranged from 0.38 ng/L - 742.73 ng/L and 0.39 ng/l - 66.3 ng/g dry weight in water and sediment samples, respectively. Genetic elements conferring resistance were recovered from all collection sites. Of the isolated bacteria, 91 (64.08%) were resistant to at least two synergistic antibiotic combinations and 11 (14.79%) were found to be resistant to 20 or more individual antibiotics. Fecal contamination was higher during the months of April and July.Conclusions.The 26 km segment of the Rio Grande River from Sunland Park NM to El Paso, TX and Juarez, Mexico is an area of concern due to poor water quality. The presence of multidrug resistant bacteria, antibiotics and mobile genetic elements may be a health hazard for the surrounding populations of this binational border region. Policies need to be developed for the appropriate management of the environmental natural resources in this border region.Competing Interests.The authors declare no competing financial interests.

Factors associated with multidrug-resistant bacteria in a cohort of patients with asymptomatic bacteriuria who underwent urological surgery

Although the factors associated to bacterial resistance in patients with asymptomatic bacteriuria (ASB) have been studied in pregnant, fertile age women, patients with spinal cord injury, and those with urogynecological disorders, nothing is known about the factors associated with multidrug-resistant (MDR) bacteria in patients with ASB and planned urological procedures. This study therefore sought to identify the sociodemographic and clinical factors associated with MDR bacteria in a cohort of patients with ASB scheduled for urological procedures. We conducted a nested case-control study on a cohort of patients with ASB and planned urological procedures at 3 Colombian medical centers. Cases were patients with MDR bacteria and controls were patients without MDR bacteria. A total of 184 patients were included, 41.8% (n = 77) of whom presented ASB with MDR bacteria. The factors linking ASB with MDR bacteria were: advanced age (odds ratio, 1.03; 95% confidence interval, 1.01-1.06) and hospitalization within the 3-month period before surgery (odds ratio, 2.35; 95% confidence interval, 1.08-5.21). Bacterial resistance is frequent among patients with ASB and planned urological procedures. Advanced age and prior hospitalization should be borne in mind for patients with planned urological procedures because they are factors associated with the presence of MDR bacteria.

Derivation and validation of a simple score to predict the presence of bacteria requiring carbapenem treatment in ICU-acquired bloodstream infection and pneumonia: CarbaSCORE

BackgroundThe recommendations of learned societies mention risk factors for the presence of multidrug resistant bacteria in hospital-acquired infections, but they do not propose a scoring system to guide empiric antibiotic therapy. Our study was aimed at developing a simple score for predicting “the presence of bacteria requiring carbapenem treatment” in ICU-acquired bloodstream infection and pneumonia.MethodsBetween December 2011 and January 2015, we conducted a retrospective study using a prospectively collected French database of nosocomial infections in the polyvalent intensive care unit of a French university hospital. All patients with ICU-acquired bloodstream infection or pneumonia were included in the study. Bivariate and multivariate analyses were performed to develop the CarbaSCORE, and this score was internally validated.ResultsIn total, 338 patients were analyzed, including 27 patients requiring carbapenem treatment. The CarbaSCORE was composed of four criteria: “presence of bloodstream infection” (as opposed to pneumonia) scored 2 points, “chronic hemodialysis” scored 4 points, “travel abroad in the last 6 months” scored 5 points, and “MDR-colonization or prior use of a β-lactam of class ≥ 3” scored 6 points. Internal validation by bootstrapping showed an area under the receiver operating characteristic curve of 0.81 [0.73–0.89]. Sensitivity was 96% at the 6-point threshold and specificity was 91% at the 9-point threshold.ConclusionsThe CarbaSCORE is a simple and efficient score for predicting the presence of bacteria requiring carbapenem treatment. Further studies are needed to test this score before it can be used in practice.

Prosthetic fungal infections: poor prognosis with bacterial co-infection.

The aims of this study were to report the efficacy of revision surgery for patients with co-infective bacterial and fungal prosthetic joint infections (PJIs) presenting to a single institution, and to identify prognostic factors that would guide management. A total of 1189 patients with a PJI were managed in our bone infection service between 2006 and 2015; 22 (1.85%) with co-infective bacterial and fungal PJI were included in the study. There were nine women and 13 men, with a mean age at the time of diagnosis of 64.5 years (47 to 83). Their mean BMI was 30.9 kg/m2 (24 to 42). We retrospectively reviewed the outcomes of these PJIs, after eight total hip arthroplasties and 14 total knee arthroplasties. The mean clinical follow-up was 4.1 years (1.4 to 8.8). The median number of risk factors for PJI was 5.5 (interquartile range (IQR) 3.25 to 7.25). All seven patients who initially underwent debridement and implant retention (DAIR) had a recurrent infection that led to a staged revision. All 22 patients underwent the first of a two-stage revision. None of the nine patients with negative tissue cultures at the second stage had a recurrent infection. The rate of recurrent infection was significantly higher in the presence of multidrug-resistant bacteria (p = 0.007), a higher C-reactive protein (CRP) at the time of presentation (p = 0.032), and a higher number of co-infective bacterial organisms (p = 0.041). The overall rate of eradication of infection after two and five years was 50% (95% confidence interval (CI) 32.9 to 75.9) and 38.9% (95% CI 22.6 to 67), respectively. The risk of failure to eradicate infection with the requirement of amputation associated with this diagnosis is much higher than in patients with PJI without bacterial and fungal co-infection, and this risk is heightened when the fungal organism is joined by polymicrobial and multidrug-resistant bacterial organisms. Cite this article: Bone Joint J 2019;101-B:582-588.

Bacteria laden street food (Chatpati) and their multiple antibiotic resistance index

The bacteria associated with street food Chatpati and their multi-drug resistance pattern were investigated. The highest bacterial load of solid part of Chatpati was recorded on NA as 1.07×105 - 9.7×105 cfu/g followed by 1.55×104 - 4.05×105 cfu/g on EMB. In case of liquid part (Spicy tamarind) maximum load was 3.1×102 - 6.4×104 cfu/ml on SS agar. The bacterial isolates were provisionally identified as Escherichia coli, Klebsiella sp., Enterobactor sp., Micrococcus variens, Staphylococcus aureus, Streptococcus faecalis and Salmonella paratyphi A. Multiple antibiotic resistance index (MRI) was found between 14.28 and 71.43%. Escherichia coli, Klebsiella sp., Enterobacter sp. and Salmonella paratyphi A showed the highest MRI percentage. Bacterial high loads and the presence of many enteric bacteria indicated significant food contamination. The presence of multi-drug resistant bacteria is very much alarming for the city dwellers habituated with the popular snacks like Chatpati.

Peripheral arterial disease increases the risk of multidrug-resistant bacteria and amputation in diabetic foot infections

The aim of this study was to investigate the microbiological profile and resistance rates of diabetic foot infections (DFIs) and to determine the effect of peripheral arterial disease (PAD) on the microbiology, clinical condition, and treatment outcomes. Characteristics, laboratory and imaging data, and the treatment modalities of patients admitted to our hospital with a diagnosis of DFI (PEDIS classification 3–4) during 2005–2016 were analyzed according to the presence of PAD. Of 112 patients who were included in this study, 86 (76.8%) had PAD. Patients with PAD were older and had higher amputation rates (P < 0.05). A microbiological profile of patients revealed a predominance of gram-positive bacteria (57.1%). Staphylococcus aureus and Streptococcus spp. were the most frequently encountered bacteria. Incidence of Pseudomonas spp. infection was higher in the PAD group (P < 0.05). Of all patients, 24.1% had multidrug-resistant (MDR) microorganisms in their wound cultures. Presence of MDR bacteria in patients with PAD was 4.9-fold higher than that in patients without PAD (P < 0.05). This retrospective study indicates that PAD has a significant role, especially in elderly patients with DFIs. Patients should be promptly evaluated and treated for PAD to prevent infections with resistant microorganisms and limb loss.

Presence of Multidrug-Resistant Bacteria on Mobile Phones of Healthcare Workers Accelerates the Spread of Nosocomial Infection and Regarded as a Threat to Public Health in Bangladesh.

Recently, mobile phones have become a potent vector for the transmission of pathogens. In hospitals, the use of the mobile phones by healthcare workers in an unhygienic manner accelerates the spread of nosocomial infection. We aimed to investigate the prevalence of microbiological contamination of mobile phones belonging to clinicians in Bangladesh hospitals. From 100 samples, we identified 69 isolates of bacteria including 22 Staphylococcus aureus; 11 Pseudomonas aeruginosa; 14 Escherichia coli; 6 Salmonella typhi 6 and 16 Staphylococcus epidermidis. On the basis of antibiotic susceptibility test using 11 antibiotics, it has been observed that most of the isolated bacteria became resistant to antibiotics and compared to other isolates, isolates of S. epidermidis and S. typhi were more resistant and sensitive, respectively. About 68.8% isolates showed that their resistance capacities against ampicillin but in contrast, 56.6% isolated were susceptible to imipenem. Azithromycin and imipenem against S. aureus, gentamicin against P. aeruginosa, tetracycline and imipenem against E. coli, tetracycline against S. typhi, and S. epidermidis revealed significant antimicrobial affectivity. We found that mobile phones are potential vectors to spread antibiotic-resistant nosocomial pathogens. Based on the study, an effective disinfection practice for cellular phones used in hospitals should be introduced to prevent the potential of cross-contamination.

Are there clinical signs and symptoms of infection to indicate the presence of multidrug-resistant bacteria in venous ulcers?

The selection of topical and systemic therapies for the treatment of venous ulcers with signs of infection is challenging and should be accompanied by specific precautionary measures to protect against cross-contamination in the presence of multidrug-resistant microorganisms. However, there are still no clinical indicators for this situation, and confirmation of resistant strains occurs through culture and sensitivity, which can take up to 14days. During this period, protective measures may no longer be taken, contributing to the spread of these pathogens. This study aimed to analyze the relationship between clinical signs and symptoms of infection in venous ulcers and the presence of antimicrobial-resistant Staphylococcus aureus and/or Pseudomonas spp. A cross-sectional study was developed including 69 patients with 98 venous ulcers. Clinical observation protocol was applied to detect infection indicators established by the European Wound Management Association and microbiological analysis of samples of the lesions. Fisher's exact test and χ2 were used for analyses (P<0.05). Two indicators of infection predominated (f >70%): discoloration of the opaque type and/or dark brick red and increased exudate volume; 31 (31.6%) ulcer samples showed positive culture for the bacteria studied. There was no relationship between signs and symptoms of infection and the presence of multidrug-resistant microorganisms. Taking into account the percentage of lesions with resistant strains, for safe care, contact precautionary measures should be implemented in the treatment rooms, in addition to standard precautions.

WITHDRAWN: Presence of multidrug resistant bacteria on mobile phones of healthcare workers accelerates the spread of nosocomial infections and regarded as a threat to public health in Bangladesh

WITHDRAWN: Presence of multidrug resistant bacteria on mobile phones of healthcare workers accelerates the spread of nosocomial infections and regarded as a threat to public health in Bangladesh

Investigation and characterization of Shiga toxin‐producing Escherichia coli present in mussels from harvesting areas in Galician southern Rias (NW Spain)

AbstractShiga toxin‐producing Escherichia coli are a known cause of serious illnesses, and a major public health concern. The coastal environment is the receptacle of agricultural and urban wastewater effluents, thus STEC can be present. In the current study their occurrence and prevalence in mussels (Mytilus galloprovincialis) cultured in the southern Rias of Galician was assessed. This region is interesting due to its economic importance as Galicia produces the 98% of the mussels cultured in Spain, being this country the third world producer. From June 2012 until September 2013, 241 mussel samples were collected, being 112 positive for eae and 17 also positive for stx1,2. An increase was observed in the winter months for both genes, which seemed correlated with a generalized decrease in water salinity. Serotype O157:H7 was not detected, but one isolate resulted resistant to six antibiotics, denoting the presence of multidrug resistant bacteria in this área.Practical applicationsA critical step for adequate risk assessments is the evaluation of potential threats. In this sense, very few microbiological parameters are analyzed in bivalve molluscs, being many human pathogens not assayed. Shiga toxin‐producing Escherichia coli was detected for the first time in mussels harvested in Galicia, a region of critical importance worldwide for the mussel industry. This study highlights that additional studies to better characterize the microbial populations of this important region are still needed, and furthermore, that measures to control microbial pathogens, such as depuration, must not be taken lightly.

Detection of Class I and II integrons for the assessment of antibiotic and multidrug resistance among Escherichia coli isolates from agricultural irrigation waters in Bulacan, Philippines

ABSTRACTContaminated irrigation water may greatly affect not only the quality of produce but also the people exposed to it. In this study, agricultural irrigation waters in Bulacan, Philippines were assessed and found to be contaminated with Escherichia coli (E. coli) ranging from 0.58 to 4.51 log10 CFU/mL. A total of 79 isolates of E. coli were confirmed through polymerase chain reaction (PCR) amplifying the uidA gene and were tested for phenotypic resistance using 10 antimicrobials through the Kirby–Bauer disc diffusion method. Forty-six isolates (58.22%) were noted to be multidrug resistant (MDR) with high resistance rate to cephalothin, tetracycline, streptomycin, ampicillin, trimethoprim, nalidixic acid, and chloramphenicol. Moreover, this study also examined the prevalence of Class I and II integrons accounting to 67.39% and 17.39%, respectively, of the MDR E. coli strains using multiplex PCR. The results imply that the agricultural water used in Bulacan is contaminated with the fecal material of man or other animals present in the area, and the presence of MDR bacteria, which pose a potential threat to individuals in these areas, is alarming. In addition, detection of integrons could be a good marker for the identification of MDR isolates. Lastly, this study could develop strategies for the proper management of farming sites leading to the detection of food-borne pathogens and prevention of infectious diseases.

Monitoring of indicator and multidrug resistant bacteria in agricultural soils under different irrigation patterns

The presence of multidrug-resistant bacteria has been proposed as an environmental impact indicator of wastewater use in agricultural soils. Nevertheless, the effect of untreated wastewater discharge on occurrence and persistence of these type of bacteria in soils is unclear. In this study, multidrug-resistant bacteria and microbial indicators of fecal contamination (coliforms and Salmonella) were determined at different depths (0–15, 15–30 and 30–50cm), in active agricultural soils under different untreated wastewater irrigation pattern (a zone with past and present wastewater irrigation; a zone with wastewater irrigation until 2003; and a zone that had never been irrigated with wastewater) in Chihuahua, Mexico. A total of 94 multidrug-resistant strains were recovered from all tested soil samples, even from those that have never been irrigated with wastewater. Higher presence (P<0.05) of multidrug-resistant bacteria was found in soils currently irrigated with untreated wastewater than in soils that has not been irrigated with wastewater for more than 10 years; the later had presence of multidrug-resistant bacteria that was statistically higher than soils that had never been irrigated with wastewater. Wastewater irrigation showed an impact on proliferation of antibiotic-resistant Gram negative bacteria in soils actually irrigated but not in Gram positive bacteria. No statistical difference was found for coliforms and Salmonella between the three soil groups. The effect of depth in multidrug-resistance bacteria presence was negligible. Although multidrug-resistant bacteria was also isolate from soils without wastewater irrigation, their persistence in a highest number in soils irrigated with wastewater suggest that use of untreated wastewater for irrigation enhance the proliferation of multidrug-resistant microorganisms which can be monitoring in soils even after a long period of time after the last irrigation.

Dental plaque bacteria with reduced susceptibility to chlorhexidine are multidrug resistant.

BackgroundChlorhexidine (CHX) is used in oral care products to help control dental plaque. In this study dental plaque bacteria were grown on media containing 2 μg/ml chlorhexidine gluconate to screen for bacteria with reduced CHX susceptibility. The isolates were characterized by 16S rRNA gene sequencing and antibiotic resistance profiles were determined using the disc diffusion method.ResultsThe isolates were variably resistant to multiple drugs including ampicillin, kanamycin, gentamicin and tetracycline. Two species, Chryseobacterium culicis and Chryseobacterium indologenes were able to grow planktonically and form biofilms in the presence of 32 μg/ml CHX. In the CHX and multidrug resistant C. indologenes we demonstrated a 19-fold up-regulation of expression of the HlyD-like periplasmic adaptor protein of a tripartite efflux pump upon exposure to 16 μg/ml CHX suggesting that multidrug resistance may be mediated by this system. Exposure of biofilms of these resistant species to undiluted commercial CHX mouthwash for intervals from 5 to 60 s indicated that the mouthwash was unlikely to eliminate them from dental plaque in vivo.ConclusionsThe study highlights the requirement for increased vigilance of the presence of multidrug resistant bacteria in dental plaque and raises a potential risk of long-term use of oral care products containing antimicrobial agents for the control of dental plaque.

Characteristics and outcomes of anti-infective de-escalation during health care-associated intra-abdominal infections.

BackgroundDe-escalation is strongly recommended for antibiotic stewardship. No studies have addressed this issue in the context of health care-associated intra-abdominal infections (HCIAI). We analyzed the factors that could interfere with this process and their clinical consequences in intensive care unit (ICU) patients with HCIAI.MethodsAll consecutive patients admitted for the management of HCIAI who survived more than 3 days following their diagnosis, who remained in the ICU for more than 3 days, and who did not undergo early reoperation during the first 3 days were analyzed prospectively in an observational, single-center study in a tertiary care university hospital.ResultsOverall, 311 patients with HCIAI were admitted to the ICU. De-escalation was applied in 110 patients (53 %), and no de-escalation was reported in 96 patients (47 %) (escalation in 65 [32 %] and unchanged regimen in 31 [15 %]). Lower proportions of Enterococcus faecium, nonfermenting Gram-negative bacilli (NFGNB), and multidrug-resistant (MDR) strains were cultured in the de-escalation group. No clinical difference was observed at day 7 between patients who were de-escalated and those who were not. Determinants of de-escalation in multivariate analysis were adequate empiric therapy (OR 9.60, 95 % CI 4.02–22.97) and empiric use of vancomycin (OR 3.39, 95 % CI 1.46–7.87), carbapenems (OR 2.64, 95 % CI 1.01–6.91), and aminoglycosides (OR 2.31 95 % CI 1.08–4.94). The presence of NFGNB (OR 0.28, 95 % CI 0.09–0.89) and the presence of MDR bacteria (OR 0.21, 95 % CI 0.09–0.52) were risk factors for non-de-escalation. De-escalation did not change the overall duration of therapy. The risk factors for death at day 28 were presence of fungi (HR 2.64, 95 % CI 1.34–5.17), Sequential Organ Failure Assessment score on admission (HR 1.29, 95 % CI 1.16–1.42), and age (HR 1.03, 95 % CI 1.01–1.05). The survival rate expressed by a Kaplan-Meier curve was similar between groups (log-rank test p value 0.176).ConclusionsDe-escalation is a feasible option in patients with polymicrobial infections such as HCIAI, but MDR organisms and NFGNB limit its implementation.

Studies on Retail Chicken Meats with A Special Reference to Antibiotic Resistant Bacteria

This study was conducted on retail chicken meats to determine the prevalence of antibiotic resistant bacteria.The prevalence of antibiotic resistant bacteria in retail chicken meat was determined in hail region, Saudi Arabia. A total of 50 samples were collected and examined for the presence of antibiotic resistant bacteria. E. coli was the most prevalent isolates (48%) followed by S. aureus (24%) and Salmonella (20%). Some of them were multi-drug resistant (MDR). Resistance of S. aureus, E. coli and Salmonella spp . to tetracycline was most frequent at 25%, 79.16% and 60%, respectively. These findings suggest that the abundant presence of multi-drug resistant bacteria in the chicken meat may have a profound effect on future treatment options for a wide range of infections caused by bacteria.

Multiple transmissible genes encoding fluoroquinolone and third-generation cephalosporin resistance co-located in non-typhoidal Salmonella isolated from food-producing animals in China

The aim of this study was to identify genes conferring resistance to fluoroquinolones and extended-spectrum β-lactams in non-typhoidal Salmonella (NTS) from food-producing animals in China. In total, 31 non-duplicate NTS were obtained from food-producing animals that were sick. Isolates were identified and serotyped and the genetic relatedness of the isolates was determined by pulsed-field gel electrophoresis of XbaI-digested chromosomal DNA. Antimicrobial susceptibility was determined using Clinical and Laboratory Standards Institute methodology. The presence of extended-spectrum β-lactamase (ESBL) and fluoroquinolone resistance genes was established by PCR and sequencing. Genes encoded on transmissible elements were identified by conjugation and transformation. Plasmids were typed by PCR-based replicon typing. The occurrence and diversity of numerous different transmissible genes conferring fluoroquinolone resistance [qnrA, qnrD, oqxA and aac(6′)-Ib-cr] and ESBLs (CTX-M-27 and CTX-M-14), and which co-resided in different isolates and serovars of Salmonella, were much higher than in European countries. Furthermore, different plasmids encoded fluoroquinolone resistance (ca. 6kb) and β-lactam resistance (ca. 63kb) and these co-resided in isolates with mutations in topoisomerase genes (gyrA and parC) giving very resistant Salmonella. The presence of multidrug-resistant bacteria in food-producing animals in countries that export foodstuffs suggests that global transfer of antibiotic resistances from country to country on food is possible.

Factors influencing the implementation of antibiotic de-escalation and impact of this strategy in critically ill patients

IntroductionA rational use of antibiotics is of paramount importance in order to prevent the emergence of multidrug resistant bacteria that can lead to therapeutic impasse, especially in intensive care units (ICUs). A de-escalation strategy is therefore naturally advocated as part of better antibiotics usage. However, the clinical impact of such a strategy has not been widely studied. We aimed to assess the feasibility and the clinical impact of a de-escalation strategy in a medical ICU and to identify factors associated when de-escalation was possible.MethodsWe performed a retrospective study of patients hospitalized in a medical ICU over a period of six months. Independent factors associated with de-escalation and its clinical impact were assessed.ResultsTwo hundred and twenty-nine patients were included in the study. Antibiotics were de-escalated in 117 patients (51%). The appropriateness of initial antibiotic therapy was the only independent factor associated with the performance of de-escalation (OR = 2.9, 95% CI, 1.5-5.7; P = 0.002). By contrast, inadequacy of initial antibiotic therapy (OR = 0.1, 0.0 to 0.1, P <0.001) and the presence of multidrug resistant bacteria (OR = 0.2, 0.1 to 0.7, P = 0.006) prevented from de-escalation. There were no differences in terms of short (ICU) or long-term (at 1 year) mortality rates or any secondary criteria such as ICU length of stay, duration of antibiotic therapy, mechanical ventilation, incidence of ICU-acquired infection, or multi-drug resistant bacteria emergence.ConclusionsDe-escalation appears feasible in most cases without any obvious negative clinical impact in a medical ICU.