Common Antimicrobials Research Articles

Streptococcus iniae biofilm formation enhances environmental persistence and resistance to antimicrobials and disinfectants

The globally distributed bacterium Streptococcus iniae is responsible for outbreaks of disease resulting in high mortality in a wide range of economically important freshwater and marine fish species. Despite the significance of S. iniae, our understanding of its transmission and infection dynamics remains incomplete. Biofilms are important for the survival and pathogenesis of many bacteria, but there is a paucity of information on their role in the ex-host persistence of S. iniae. This study aimed to compare biofilm formation by isolates representing different S. iniae genotypes and to investigate the effect of biofilm formation on environmental persistence and resistance to common disinfectants and antimicrobials. Eleven clinical isolates of S. iniae representing 4 distinct genetic groups and diverse host types were assessed for their ability to form biofilms. Planktonic bacteria or mature biofilms were exposed to in vitro aquatic microcosms of different temperatures to quantify the number of culturable bacteria in each system over time. The minimum biofilm eradication concentration (MBEC) assay® system was used to determine biofilm resistance to 18 antimicrobials and 4 disinfectants commonly used in food producing animals and aquaculture, respectively. All isolates formed biofilms within 72 h. Bacteria remained culturable notably longer in the biofilm form compared to the planktonic, with a significant impact from temperature and salinity (p < 0.05). The MBEC was higher than the planktonic minimal inhibitory concentration (MIC) for at least one isolate in 15 out of the 18 antimicrobials tested. The MBEC was also higher than the minimum biocidal concentration (MBC) for 11 out of 18 tested, including oxytetracycline and florfenicol, the two most common antimicrobials used against S. iniae infections in fish. While both forms were susceptible to disinfection by bleach, hydrogen peroxide and Virkon® Aquatic, treatment with povidone‑iodine did not eliminate biofilms. The ability of S. iniae to form resilient biofilms provides an effective mechanism for their persistence in the environment, which must be considered and further researched to control this widespread pathogen.

Appropriateness of antimicrobial prescribing in the high-burden emergency department of a tertiary hospital in Malaysia.

Background Appropriate antimicrobial prescribing in the emergency department (ED) is a challenge due to diagnostic uncertainty, time pressure, and clinical inertia.Objective To assess the appropriateness of antimicrobial prescribing in the ED.Setting This study was conducted in the inpatient ED of a tertiary hospital in Malaysia. Method We conducted a 6-month retrospective antimicrobial prescriptions analysis among ED patients who received intravenous antimicrobial. Antimicrobial prescriptions of conveniently selected adult patients were evaluated with the medication appropriateness index.Main outcome measure Appropriateness of antimicrobial prescribing was the primary outcome measure. Results We analysed 310 patients with 326 antimicrobial prescriptions. Ceftriaxone (41.1%, n = 134) and amoxicillin-clavulanate (36.5%, n = 119) were the most common antimicrobials prescribed. Respiratory infections (71.5%, n = 233) was the main indication for antimicrobial therapy in the ED. All antimicrobials prescribed were indicated as per the Malaysian antimicrobial guidelines. The overall rate of inappropriate antimicrobial prescribing was 53.1% (n = 173). Thirty-two (9.8%) antimicrobials were prescribed with inappropriate doses; the majority was related to beta-lactam/beta-lactamase dose (p = 0.002). One hundred and forty-three (43.9%) antimicrobials prescribed had alternatives with similar efficacy but were less costly; which referring to ceftriaxone usage (p < 0.001). Conclusions The inappropriate antimicrobial prescribing in the emergency department is prevalent. This emphasises the importance of conducting antimicrobial stewardship initiative in the ED to improve the appropriate dosing of beta-lactam/beta-lactamase inhibitors as well as the judicious use of ceftriaxone.

Analysis of antibiotic resistance phenotypes and genes of Escherichia coli from healthy swine in Guizhou, China.

This study was carried out to investigate the resistance phenotypes and resistance genes of Escherichia coli from swine in Guizhou, China. A total of 47 E. coli strains isolated between 2013 and 2018 were tested using the Kirby–Bauer (K–B) method to verify their resistance to 19 common clinical antimicrobials. Five classes consisting of 29 resistance genes were detected using polymerase chain reaction. The status regarding extended-spectrum β-lactamase (ESBL) and the relationship between ESBL CTX-M-type β-lactamase genes and plasmid-mediated quinolone resistance (PMQR) genes were analysed. A total of 46 strains (97.9%) were found to be multidrug resistant. Amongst them, 27 strains (57.4%) were resistant to more than eight antimicrobials, and the maximum number of resistant antimicrobial agents was 16. Twenty antibiotic resistance genes were detected, including six β-lactamase genes blaTEM (74.5%), blaCTX-M-9G (29.8%), blaDHA (17.0%), blaCTX-M-1G (10.6%), blaSHV (8.5%), blaOXA (2.1%), five aminoglycoside-modifying enzyme genes aac(3′)-IV (93.6%), aadA1 (78.7%), aadA2 (76.6%), aac(3′)-II c (55.3%), aac(6′)-Ib (2.1%) and five amphenicol resistance genes floR (70.2%), cmlA (53.2%), cat2 (10.6%), cat1 (6.4%), cmlB (2.1%), three PMQR genes qnrS (55.3%), oqxA (53.2%), qepA (27.7%) and polypeptide resistance gene mcr-1 (40.4%). The detection rate of ESBL-positive strains was 80.9% (38/47) and ESBL TEM-type was the most abundant ESBLs. The percentage of the PMQR gene in blaCTX-M-positive strains was high, and the detection rate of blaCTX-M-9G was the highest in CTX-M type. It is clear that multiple drug resistant E. coli is common in healthy swine in this study. Extended-spectrum β-lactamase is very abundant in the E. coli strains isolated from swine and most of them are multiple compound genotypes.

Phenotypic and Genotypic Characterization of Metallo Beta Lactamases among Gram-Negative Uropathogens from a Tertiary Care Hospital in Egypt: A Cross Sectional Study

Background: Gram Negative bacilli (GNB) are the most common causes of urinary tract infections (UTIs). There is a worrying level of antimicrobial resistance emerging in UTIs pathogens. Metallo-β-lactamases (MBLs) are rapidly spreading β-lactamases with no available FDA approved inhibitor conferring resistance to most β-lactam antibiotics including carbapenems. We aimed to determine prevalence and antimicrobial resistance patterns of Gram-negative uropathogens in our tertiary care hospital, and to characterize MBLs production among them.Methods: A hundred and forty-three urine samples were collected from the Urology Department. Uropathogens were isolated on Cystiene Lactose Electrolyte Deficient agar and Mac-Conkey’s agar. GNB were identified by conventional methods. Antimicrobial susceptibility was evaluated by disc diffusion method. Carbapenems resistant Gram-negative bacilli (CRGNB) were tested for MBLs production both phenotypically and genotypically.Results: Eighty-five GNB (75.9%) were isolated from 112 positive cultures. Escherichia coli (49.4%) was the most prevalent isolate. Most of GNB showed high resistance patterns to various antimicrobials. Twenty-nine GNB isolates were resistant to at least one carbapenem (28.2% for imipenem, 30.6% for meropenem). Twenty-three isolates (79.3%) were phenotypically positive for MBL activity by combined disc test (CDT). Twenty-two isolates (75.9%) were positive for one or more of MBL genes (blaIMP, blaVIM and/or blaNDM).Conclusions: Our study emphasized on the alarming rates of resistance to most of the common antimicrobials particularly carbapenems among GNB uropathogens, which represent a public health threat. CRGNB isolates in our hospital are phenotypically and genotypically associated with MBLs production so an effective strategy to combat these strains is mandatory.

Quorum Sensing Inhibition or Quenching in Acinetobacter baumannii: The Novel Therapeutic Strategies for New Drug Development

Acinetobacter baumannii is a Gram-negative opportunistic nosocomial pathogen, which can cause ventilator-related and blood infection in critically ill patients. The resistance of A. baumannii clinical isolates to common antimicrobials and their tolerance to desiccation have emerged as a serious problem to public health. In the process of pathogenesis, bacteria release signals, which regulate virulence and pathogenicity-related genes. Such bacteria coordinate their virulent behavior in a cell density-dependent phenomenon called quorum sensing (QS). In contrast, the two main approaches of QS interference, quorum sensing inhibitors (QSIs) and quorum quenching (QQ) enzymes, have been developed to reduce the virulence of bacteria, thus reducing the pressure to produce bacterial drug resistance. Therefore, QSIs or QQ enzymes, which interfere with these processes, might potentially inhibit bacterial QS and ultimately biofilm formation. In this review, we aim to describe the state-of-art in the QS process in A. baumannii and elaborate on the use of QSIs or QQ enzymes as antimicrobial drugs in various potential sites of the QS pathway.

Quality Analysis of Antimicrobial Restriction Policy in Pediatrics

Background: Antimicrobial stewardship programs (ASPs) are coordinated programs developed in recent years to promote the appropriate use of antimicrobials and reduce microbial resistance. One important action for a successful ASP is the implementation of an antimicrobial policy restriction. Objective: The study analyzed the quality of target-antimicrobial requisitions after the introduction of an antimicrobial policy restriction for children. Methods: We conducted a retrospective study in a neonatal intensive care unit (NICU) and three pediatric intensive care units (PICUs). An ASP was implemented in October 2016, and 14 target antimicrobials were selected to be prescribed after pre-approval by a pediatric infectious disease specialist. All requisitions were analyzed according to indication, antimicrobial type, dose, duration, and collection of cultures before administration. There were no exclusion criteria for requisition analysis. Results: Between October 2016 and December 2017, 1,173 patients were admitted to the units with 120 requisitions of target antimicrobials. Sepsis (43/120; 35.8%) was the most common indication, followed by respiratory infections (23/120; 19.2%) and infections in two or more sites (11/120; 9.2%). The most common target antimicrobials requested were meropenem (68/120; 56.7%), amphotericin B lipid formulations (12/120; 10%), teicoplanin (11/120; 9.2%), and linezolid (11/120; 9.2%). In 98 (81.7%) cases, previous cultures before antimicrobial administration were collected. An infectious agent was detected in 52 of the 98 cultures (53.1%), and Gram-negative and Gram-positive bacteria represented 50% and 26.9% of all positive samples, respectively. Besides, 111 (92.5%) requisitions were approved. In five refused requisitions, a narrow-spectrum antimicrobial was prescribed after further discussion; four were refused due to lack of information, and in one case, the de-escalation of the antimicrobial was possible. No mistake regarding dosage and duration was detected. Conclusions: We found a high-quality rate of target antimicrobial requisition. Antimicrobial policy restriction could contribute to improving the quality of antimicrobial prescription, even in NICUs and PICUs.

Prevalence of Antimicrobial Resistant of Vibrio parahaemolyticus Isolated from Diarrheal Patients - Six PLADs, China, 2016-2020.

What is already known on this topic?Vibrio parahaemolyticus (V. parahaemolyticus) is frequently resistant to common antimicrobials such as ampicillin and generally highly susceptible to most clinically used antimicrobials. What is added by this report?V. parahaemolyticus were highly resistant to cefazolin and ampicillin: 94.4% and 37.0%, respectively. However, it was below 3% resistance to all 10 other antimicrobials including clinically relevant agents and even imipenem. The overall levels of antimicrobial resistance and multidrug resistance were 95.1% and 3.3%, respectively. The distribution of antimicrobial resistance and the multidrug resistance had regional, temporal, sexual, and isolated source strain variation. What are the implications for public health practice?This study provides data on drug resistance of V. parahaemolyticus in Chinese clinical settings, which will help develop a public health strategy.

379. Epidemiology of Antimicrobial Use Among SARS-CoV-2 Positive and Negative Admissions in the US: A Multicenter Evaluation

BackgroundSARS-CoV-2, a novel coronavirus, emerged in Wuhan, China in December of 2019, and became a pandemic. Increases in bacterial/fungal co-infections have occurred during influenza pandemics and early data from this pandemic indicate high utilization of antimicrobial therapy. We compared the utilization of antimicrobials and health outcomes between SARS-CoV-2 positive and negative patients.MethodsPatients hospitalized at 271 US acute care facilities from 3/1/20–5/30/20 with ≥1 day length of stay (LOS) and ≥24 hours of antimicrobial therapy tested for SARS-CoV-2 were included in the study (BD Insights Research Database [Becton, Dickinson & Company, Franklin Lakes, NJ]). Demographics, antimicrobial utilization, duration of antimicrobial therapy, hospital LOS and ICU LOS data were analyzed by SARS-CoV-2 test results.Results142,054 patients were tested for SARS CoV-2 and 12% (n=17,075) were SARS-CoV-2 positive. SARS-CoV-2 negative and positive patients did not differ regarding presence of a positive bacterial culture. Total LOS, % ICU admission, and ICU LOS were higher among SARS-CoV-2 positive patients (Table). In total 48% of admissions were prescribed antimicrobial therapy; rates were higher in SARS-CoV-2 positive versus negative admissions (68% vs. 46%). The most common antimicrobials and classes are in Table.Antimicrobial therapy and outcomes in hospitalized SARS-CoV-2 tested patients. ConclusionAlmost half of patients tested for SARS-CoV-2 were prescribed antimicrobials, with antimicrobial use higher among those with SARS-CoV-2, despite similar rates of positive cultures. On average, antimicrobials were prescribed within 10 hours from the time to admission among patients tested. These treatment patterns may highlight the difficulties in making treatment decisions and concerns over potential bacterial superinfection in SARS-CoV-2, but also indicate potential overuse of antimicrobials. Collateral damage from antimicrobial overuse include increase selection of antimicrobial resistance, adverse effects of drugs, and unnecessary treatment costs. It will be important to continue to evaluate the utilization and appropriateness of antimicrobial use among SARS-CoV-2 patients.DisclosuresLaura A. Puzniak, PhD, Merck (Employee) Karri A. Bauer, PharmD, Merck Research Laboratories (Employee) Lyn Finelli, DrPH, MS, Merck & Co Inc, (Employee) Carisa De Anda, PharmD, Merck & Co Inc, (Employee) Pamela Moise, PharmD, Merck & Co., Inc. (Employee, Shareholder) Kalvin Yu, MD, Becton, Dickinson and Company (Employee)GlaxoSmithKline plc. (Other Financial or Material Support, Funding) Latha Vankeepuram, MS, BD (Employee) Prashant Parikh, n/a, Becton, Dickinson and Company (Employee) Vikas Gupta, PharmD, BCPS, Becton, Dickinson and Company (Employee, Shareholder)GlaxoSmithKline plc. (Other Financial or Material Support, Funding)

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment.

Antimicrobial compounds are used in a broad range of personal care, consumer and healthcare products and are frequently encountered in modern life. The use of these compounds is being reexamined as their safety, effectiveness and necessity are increasingly being questioned by regulators and consumers alike. Wastewater often contains significant amounts of these chemicals, much of which ends up being released into the environment as existing wastewater and sludge treatment processes are simply not designed to treat many of these contaminants. Furthermore, many biotic and abiotic processes during wastewater treatment can generate significant quantities of potentially toxic and persistent antimicrobial metabolites and byproducts, many of which may be even more concerning than their parent antimicrobials. This review article explores the occurrence and fate of two of the most common legacy antimicrobials, triclosan and triclocarban, their metabolites/byproducts during wastewater and sludge treatment and their potential impacts on the environment. This article also explores the fate and transformation of emerging alternative antimicrobials and addresses some of the growing concerns regarding these compounds. This is becoming increasingly important as consumers and regulators alike shift away from legacy antimicrobials to alternative chemicals which may have similar environmental and human health concerns.

BlaNDM gene identified from clinical samples of companion animals: First description in Brazil

Background: Emergence of acquired carbapenemases and their worldwide dissemination are a major global threat to antibiotic era and represent a major clinical challenge in both human and veterinary contexts. Carbapenems are broad-spectrum beta-lactam antibiotics employed for treatment of serious infections, usually considered as the last-line available therapy against multidrug-resistant (MDR) Gram-negative bacterial infections like those caused by extended spectrum beta-lactamase (ESBL) pathogens. The New Delhi metallo-beta-lactamase (NDM) was named after being discovered in India, in 2009, and has been isolated in several parts of the world. Until now, the occurrence of NDM appeared to be restricted mainly to humans, however the prevalence and characteristics of MDR genes in Enterobacteriaceae originating from companion animals are still not well known. Thus, this study aimed to investigate the occurrence of carbapenemase encoding genes in bacteria resistant to carbapenems, isolated from clinical samples of companion animals. Methods and materials: There were considered bacterial isolates from dogs (97 strains) and cats (24 isolates) showing phenotypic resistance to carbapenems, identified during routine microbiological investigation between July 2018 and April 2019 in Joinville, Southern Brazil. Phenotypic resistance to carbapenems and the susceptibility profile to other common antimicrobials were determined by the disc-diffusion agar method. In addition, Modified Carbapenem Inactivation Method (mCIM) was used for phenotypic confirmation of carbapenemases in Enterobacteriaceae. The presence of blaNDM gene was confirmed by Real-time Polymerase Chain Reaction employing TaqMan probes. Results: In this study, there were identified two MDR isolates (Klebsiella pneumoniae and Enterobacter cloacae) carrying the blaNDM gene derived from dogs urine. Conclusion: To our knowledge, this is the first report of NDM identified in clinical isolates derived from companion animals in Brazil. Of note, the blaNDM gene may be located in readily transferable plasmids, increasing the variety of transmission vectors of resistance to carbapenems, also considering that the species carrying the gene identified in this study are widely distributed and shared among the environment, animals and humans.

Genomic investigations of S. Typhi isolated from Community and Hospital settings – An update from SEFI network

Background: S. Typhi “H58/4.3.1”, a single dominant MDR-lineage has emerged and spread throughout Asia and Africa over the last 30 years. A large global study speculated South Asia might be the site of original emergence of 4.3.1. Through an ongoing national-wide network of Surveillance of Enteric Fever in India (SEFI), we aim to study the genomic signatures of S. Typhi across different settings. We undertook this study to determine the genotypes of S. Typhi isolated from community (Tier-1) and Hospital (Tier-3) settings in a Southern India region. Methods and materials: A total of 193 and 200 S. Typhi isolated from Tier 1 (Jan-2017 to Sep-2019) and Tier 3 (Nov-2017 to Sep-2019) as part of the network was included. Susceptibility testing was done for most common antimicrobials. At present, whole genome sequencing was done for 30 strains each from Tier-1 and 3. SNP and comparative genomic analysis of Tier 1 and 3 was done to infer difference in the genomic signatures. Geospatial mapping was generated for Tier 1 strains for cluster analysis to infer transmission-dynamic events. Results: Susceptibility rates to first-line agents were highest among community strains with no MDR, whereas 8 MDR strains were isolated from hospital cases. Ciprofloxacin resistance was seen in 5% (9/193) of community isolates compared to the high rates 32% (63/200) among hospital isolates. Notably, genomic analysis showed the dominance of a single H8-lineage 4.3.1.2 (30/30) in community isolates. However, hospital isolates had broader distribution such as 4.3.1.2 (18), 4.3.1.1 (7), 4.3.1.3 (1) and 2.2 and 3.3 respectively. Within the community collection, two sub groups with respect to QRDR profile with S83Y (SG-I) and S83F (SG-II) were found. Interestingly, all SG-II (17/30) appeared to be a single strain with no SNPs differences, being circulated in a defined community setting over 3 months. Conclusion: The baseline data generated here provides multiple insights in terms of a single clade 4.3.1.2 dominating in a community setting, while diverse genotypes seen among typhoid cases attending a tertiary care hospital. However, phylo-geographical analysis of all the isolates would provide a clear picture of the ongoing transmission dynamics between two settings.

Antifungal treatment administered in OPAT programs is a safe and effective option in selected patients

IntroductionOutpatient parenteral antimicrobial therapy (OPAT) has been recognised as a useful, cost-effective and safe alternative to inpatient treatment. Nevertheless, the most common antimicrobials used are antibiotics, and there is less information about the use of antifungal therapy (AT). The aim of this study is to analyse a cohort of patients treated with AT administered via OPAT and to compare them with patients from the rest of the cohort (RC) treated with antibiotics. MethodsProspective observational study with post hoc (or retrospective) analysis of a cohort of patients treated in the OPAT program. We selected the patients treated with antifungals between July 2012 and December 2018. We recorded demographic and clinical data to analyse the validity of the treatment and to compare the differences between the AT and the RC. ResultsOf the 1101 patients included in the OPAT program, 24 (2.18%) were treated with AT, 12 Liposomal Amphotericin B, 6 echinocandins and 6 fluconazole. This result is similar to other cohorts. There were differences between the AT vs RC in the number of patients with neoplasia (58.3% vs 28%; p=0.001), IC Charlson>2 (58.3% vs 38.8; p=0.053), duration of treatment (15 days vs 10.39 days; p=0.001) and patients with central catheters (54.2% vs 21.7%; p=0.0001). These differences are justified because there were more hematologic patients included in the AT group. Nevertheless, there were no differences in adverse reactions (25% vs 32.3%; p=0.45) or re-admissions (12.5% vs 10%; p=0.686) and OPAT with AT was successful in 21/24 patients (87.5%). ConclusionsAT can be successfully administered in OPAT programs in selected patients, that are clinically stable and monitored by an infectious disease physician.

Antimicrobials use and resistance on integrated poultry-fish farming systems in the Ayeyarwady Delta of Myanmar

Antimicrobials are used to support livestock health and productivity, but might pose a risk for the development of antimicrobial resistance; in particular, when multiple livestock species are raised together in production systems. On integrated chicken-fish farms, chickens are raised over fish ponds and poultry faeces is excreted into the ponds. We investigated antimicrobial usage and the antimicrobial susceptibility of Escherichia coli cultured from poultry faeces on 301 integrated farms in Ayeyarwady Delta of Myanmar. Antimicrobials were used by 92.4% of farmers for chickens, but they were not applied to fish. The most common antimicrobials used were Octamix (amoxicillin and colistin sulfate) on 28.4%, enrofloxacin on 21.0% and amoxicillin on 16% of farms. Overall, 83.1% (152/183) of the E. coli were resistant to at least one antimicrobial. The highest level of resistance was to amoxicillin (54.6%), tetracycline (39.9%), sulfamethoxazole/trimethoprim (35.5%) and enrofloxacin (34.4%). Multidrug resistance was identified in 42.4% of isolates. In general, we found similar levels of antimicrobial resistance in non-users of antimicrobials as in users of antimicrobials for more commonly applied antimicrobials. Overall, antimicrobial resistance was lower in chickens on these integrated farms in Myanmar, compared to poultry farms in other countries of South East and East Asia.

Current Antibiotic Resistance Trends of Uropathogens in Central Europe: Survey from a Tertiary Hospital Urology Department 2011-2019.

Monitoring of pathogen resistance profiles is necessary to guide empirical antibiotic therapy before culture and sensitivity results become available. The aim of this study was to describe current antibiotic resistance patterns of five most frequent causative uropathogens in a Department of Urology of a tertiary referral centre in Central Europe over a period of nine years. The Hospital Department of Clinical Microbiology database was used to extract data on all positive urine samples from inpatients in the Department of Urology between 2011 and 2019. Numbers of susceptible and resistant isolates per year were calculated for five most frequent uropathogens: Escherichia coli, Enterococcus spp., Klebsiella spp., Pseudomonas aeruginosa, and Proteus spp. Antimicrobial agents selected for the survey included: ampicillin, amoxicillin/clavulanic acid, piperacillin/tazobactam; cefuroxime, cefotaxime, ceftazidime and cefepime; ciprofloxacin and ofloxacin; gentamicin and amikacin; ertapenem, meropenem and imipenem; trimethoprim-sulfamethoxazole (co-trimoxazole), nitrofurantoin, colistin, and vancomycin. High resistance rates of Gram-negative uropathogens were demonstrated to most common antimicrobials, with statistically significant increasing or decreasing trends in some cases. No carbapenem-resistant Enterobacteriaceae were isolated. Vancomycin-resistant Enterococcus spp. strains were rare in our population.

Infective endocarditis by Proteus species: a systematic review.

Proteus spp. are members of the Enterobacteriaceae family and are Gram-negative, rod-shaped bacteria known to mainly cause urinary tract infections (UTIs) in humans. However, even though scarce evidence exists suggesting their potential to cause infective endocarditis (IE), a study summarizing the existing evidence is lacking. The purpose of this study was to systemically review all published cases of IE by Proteus species in the literature. A systematic review of PubMed, Scopus and Cochrane Library (through 5th May 2020) for studies providing epidemiological, clinical and microbiological data as well as data on treatment and outcomes of IE by Proteus species was performed. A total of 16 studies, containing data of 16 patients, were included. A prosthetic valve was present in 25%, while the most common causative pathogen was P. mirabilis. Aortic valve was the most common infected site in 33.3%, followed by mitral valve in 26.7%. Diagnosis was set with transesophageal echocardiography in 37.5%, and transthoracic echocardiography in 25%, while the diagnosis was set at autopsy in 25%. Fever and sepsis were present in 100% and 84.6%, respectively. Aminoglycosides and cephalosporins were the most common antimicrobials used for treatment. Clinical cure was noted in 62.5%, while overall mortality was 43.8%. This systematic review describes IE by Proteus species in detail and provides information on epidemiology, clinical presentation, treatment and outcomes.

Prevalence of Salmonella serotypes S. Enteritidis and S. Typhimurium in poultry and poultry products

AbstractSalmonella continues to be a major food safety and public health threat. In the present study, Salmonella enterica subsp. enterica serotypes Enteritidis (SE) and Typhimurium (ST) were isolated from poultry and characterized for virulence, antimicrobial susceptibility, and biofilm formation. Prevalence of Salmonella serotypes in poultry was 3.35%; predominant serotypes isolated were S. Enteritidis (68.1%) and S. Typhimurium (31.8%). Source‐wise, Salmonella were isolated from retail market chicken meat (4.8%), live chicken at farm (2.5%), and table eggs (2.1%). Salmonella isolates produced invA gene of 284 bp (100%), spvR gene of 310 bp (77.27%), spvC gene of 571 bp (22.72%), and stn gene of 260 bp (100%) as virulence/ pathogenicity determinants. Salmonella isolates exhibited resistance to common antimicrobials; 72.7% isolates showed multiple resistance (≥3 antimicrobial class), highest resistance was observed for polymyxin‐B (81.8%) followed by nalidixic acid (72.7%), colistin (59.1%), ampicillin/tetracyline (45.5%), ampicillin + sulbactam (40.9%), cefodroxil (18.2%), streptomycin (9.1%), and cefazidine/ceftriaxone‐tazobactam (4.5%). Multiple antimicrobial resistance (MAR) index of poultry Salmonella isolates ranged from 0.11 to 0.35; wherein, 59.1% isolates showed MAR of &gt;0.2. About 81.8% Salmonella isolates produced biofilm and were categorized as strong (13.6%), moderate (45.4%), and weak (22.7%) biofilm producers. Occurrence of antimicrobial resistant virulent Salmonella strains in poultry requires implementation of suitable strategies so as to protect the public health.

Microorganisms associated with incisional infections after gastrointestinal surgery in dogs and cats.

To determine the rate of incisional infections after gastrointestinal surgery in dogs and cats and describe the aerobic bacteria isolated from these infections. Retrospective study. Client-owned dogs (n = 210) and cats (n = 66). Records of dogs and cats that underwent gastrointestinal surgery at the Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania were reviewed for surgical procedures, presence of an infection, bacterial species isolated, perioperative antimicrobials administered, and outcome. The median duration of follow-up was 14 days (4-35). Incisional infections were recorded in 7% (20/276) of cases. Among those 20 cases, culture results were available in 12 of 20 cases. The most common bacterial isolate cultured was Escherichia coli. The most common perioperative antimicrobials administered to treat incisional infection were cefazolin and cefoxitin. Only two of the bacterial isolates were susceptible to these antimicrobials. Bacteria isolated from incisional infections were most often susceptible to chloramphenicol, imipenem, and gentamicin. Bacterial isolates from incisional infections in this population consisted of native gastrointestinal flora, which was often resistant to the most commonly used perioperative antimicrobials. Contamination at time of surgery is the most likely source of incisional infection after gastrointestinal surgery. This rate of infection justifies more rigorous intraoperative hygiene protocols and evaluation of the antimicrobials' susceptibility of causative bacteria to guide antimicrobial treatment.

Measuring antimicrobial prescribing quality in outpatient parenteral antimicrobial therapy (OPAT) services: development and evaluation of a dedicated national antimicrobial prescribing survey.

BackgroundAntimicrobial stewardship programmes are important in driving safety and quality of antimicrobial prescribing. The National Antimicrobial Prescribing Survey (NAPS) is a point-prevalence audit of inpatient antimicrobial prescribing in Australian hospitals.ObjectivesTo design and adapt the NAPS tool for use in the outpatient parenteral antimicrobial therapy (OPAT) and hospital-in-the-home (HITH) setting.MethodsAn inter-disciplinary working group with expertise in OPAT and HITH services was established to adapt the NAPS template for use in the OPAT setting—called HITH-NAPS. This was initially trialled in 5 HITH services, subsequently adapted following participant feedback, then offered nationally to 50 services in 2017.ResultsThere were 1154 prescriptions for 715 patients audited via the HITH-NAPS. The most common antimicrobials prescribed were cefazolin (22%), flucloxacillin (12%), piperacillin/tazobactam (10%) and ceftriaxone (10%). The most common infections treated were cellulitis (30%) and respiratory tract infections (14%). Eighty-seven percent of prescriptions were assessed as appropriate, 11% inappropriate and 2% not assessable. Prolonged durations of antimicrobials and unnecessarily broad-spectrum antibiotics were used in 9% of prescriptions.ConclusionsThe HITH-NAPS pilot project revealed that auditing of this type is feasible in HITH. It showed that antibiotic use in these HITH services was generally appropriate, but there are some areas for improvement. A national OPAT/HITH-NAPS can facilitate benchmarking between services, identify potentially inappropriate prescribing and help guide quality improvement.

Antibiotic use among surgical inpatients at a tertiary health facility: a case for a standardized protocol for presumptive antimicrobial therapy in the developing world

SummaryBackgroundIndiscriminate antimicrobial use is one of the greatest contributors to antimicrobial resistance. A low level of asepsis in hospitals and inadequate laboratory support have been adduced as reasons for indiscriminate use of antimicrobials among surgical patients. At present, there are no guidelines for presumptive antibiotic use in Nigeria and sub-Saharan Africa.AimSurgical inpatients at the study hospital were surveyed to determine the level of antimicrobial use and degree of compliance with prescription quality indicators.MethodsA cross-sectional survey was conducted among all surgical inpatients in May 2019 using a standardized tool developed by the University of Antwerp to assess the point prevalence of antimicrobials. Inpatients who were admitted from 08:00 h on the day of the survey were included. Data on patients' demographics, indication for antimicrobial use, reason for antimicrobial use, stop/review date, adherence to guidelines and laboratory use were collected. The prevalence of antimicrobial use in the surgical department was estimated.ResultsEighty-two inpatients were included in the survey. Of these, 97.6% were receiving at least one antimicrobial agent. Only 5.4% of the prescriptions were targeted, and 37.6% of prescriptions were for empirical treatment of infections. Approximately half (50.7%) of the patients were receiving presumptive antibiotics, and 6% were receiving prophylactic antibiotics. In total, 58.7% of prescriptions were administered parenterally, and 98.2% of patients had documentation of a stop/review date. Metronidazole (P=32.3%, T=29.2%), ceftriaxone (P=28.4%, T=19.8%) and ciprofloxacin (P=14.2%, T=14.6%) were the most common antimicrobials used.ConclusionsThere is a high rate of antimicrobial use among surgical inpatients, and the rate of indiscriminate antimicrobial prescribing among these patients needs to be reduced. This can be achieved by developing antimicrobial guidelines for presumptive antimicrobial therapy.

Antimicrobial Susceptibility and Cross-Resistance Patterns among Common Complicated Urinary Tract Infections in U.S. Hospitals, 2013 to 2018.

In the face of increasing rates of antimicrobial resistance in complicated urinary tract infections (cUTIs), clinicians need to understand cross-resistance patterns among commonly encountered pathogens. We performed a multicenter, retrospective cohort study in the Premier database of approximately 180 hospitals, from 2013 to 2018. Using an ICD-9/10-based algorithm, we identified all adult patients hospitalized with cUTIs and included those with a positive blood or urine culture. We examined the microbiology and susceptibilities to common cUTI antimicrobials (3rd-generation cephalosporin [C3], fluoroquinolones [FQ], trimethoprim-sulfamethoxazole [TMP/SMZ], fosfomycin [FFM], and nitrofurantoin [NFT]) singly and in groups of two. Among 28,057 organisms from 23,331 patients, the 3 most common pathogens were Escherichia coli (41.0%; C3r, 15.1%), Klebsiella pneumoniae (12.1%; C3r, 13.2%), and Pseudomonas aeruginosa (11.0%; C3r, 12.0%). E. coli was most frequently resistant to FQ (43.5%) and least to NFT (6.7%). K. pneumoniae was most frequently resistant to NFT (60.8%) and least to FFM (0.1%). P. aeruginosa was most frequently resistant to FQ (34.4%) and least to TMP/SMZ (4.2%). Of the C3rE. coli isolates, 87.1% were also FQr, 63.7% were TMP/SMZr, and 13.3% were NFTr C3rK. pneumoniae isolates had a 76.5% chance of being FQr, 78.1% were TMP/SMZr, and 77.6% were NFTr C3rP. aeruginosa coexisted with FQr in 47.3%, TMP/SMZr in 18.9%, and NFTr in 28.7%. Among the most common pathogens isolated from hospitalized patients with cUTIs, the rates of single resistance to common treatments and of cross-resistance to these regimens are substantial. Knowing the patterns of cross-resistance may help clinicians tailor empirical therapy more precisely.