High Susceptibility Rates Research Articles

Prevalence and molecular epidemiology of ceftaroline non-susceptible methicillin-resistant Staphylococcus aureus isolates, first clinical report from Iran.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major pathogens in Iran with a high prevalence and a high level of antibiotic resistance. Ceftaroline is a fifth generation cephalosporin binding and inhibiting penicillin binding protein (PBP2a). In the present study, 228 clinical MRSA isolates were collected from four cities of Iran and their susceptibility to ceftaroline was evaluated by E-test and the disk diffusion method. Our results showed a high susceptibility rate (97.3%) to ceftaroline in MRSA strains from Iran. Six isolates were found to be ceftaroline non-susceptible (CPT-NS) with Minimum inhibitory concentration (MIC) ≥2 µg/mL. All CPT-NS isolates were isolated from blood and tracheal aspirate and belonged to SCCmec type III as well as agr type I and were all susceptible to vancomycin. Out of six isolates, three, two and one belonged to spa type t030, t4864, and t969, respectively. Vancomycin, quinupristin/dalfopristin, linezolid, chloramphenicol, and tigecycline were the most active agents against CPT-NS isolates. Due to the broad-spectrum activity and low toxicity of ceftaroline as well as the increased rate of vancomycin resistance among MRSA strains in recent years, ceftaroline can be considered as a novel approach to treat MRSA-induced infections.

Microbiological profile and their antibiotic sensitivity pattern in patients of chronic suppurative otitis media at eastern tertiary care center of Nepal

Chronic suppurative otitis media (CSOM) is one of the most common and an important global public health problem leading to hearing impairment and is particularly prevalent in developing countries. Even in this era of powerful antibiotics, due to increased irrational use of wide spectrum antibiotics, the resistance in the bacterial isolates is common. The objective of the study was to determine the aerobic bacterial etiology of patients with CSOM and the antimicrobial susceptibility of the bacteria isolated.A descriptive cross sectional study was carried out in 112 patients suffering from chronic discharging ear. Pus samples were cultured aerobically. Antibiotic sensitivity testing was performed with standard antibiotic discs using modified Kirby-Bauer disk diffusion method.Out of 112 patients, 70 (62.5%) were females. Among 112 swab cultures, 98 (87.5%) were positive for the growth of organism and 14 (12.5%) were sterile cultures. Among them Staphylococcus aureus (42.24%), Pseudomonas aeruginosa (28.44%), Klebsiella pneumoniae (10.34%), Acinetobacter anitratus (6.9%), Proteus mirabilis (5.17%) and E. coli (4.31%) were the common microbial isolates. Among the antibiotics commonly available as topical eardrops, Ofloxacin (91.83%)) had the highest susceptibility rate, followed by Ciprofloxacin (81.63%), Tobramycin (73.46%) and Gentamicin (63.26%).Staphylococcus aureus was the most common organism isolated followed by Pseudomonas aeruginosa. Ofloxacin had the highest susceptibility rate against the isolated organisms.

Antimicrobial Resistance among Community-Acquired Uropathogens in Mashhad, Iran.

Background Antimicrobial resistance among community-acquired uropathogens is an emerging concern over the past decades that warrants a continuing reevaluation of the appropriateness of recommended empiric antimicrobial regimens for treatment of urinary tract infections (UTIs). Aims To describe the microbial spectrum and resistance profile of community-acquired uropathogens and predictors of isolation of resistant strains. Methods Between October 2017 and June 2019, individuals who visited the outpatient clinics for diagnosis of UTIs or screening of asymptomatic bacteriuria were included in the study if they were tested for urine culture in one of the three main medical diagnostic laboratories of Mashhad, Iran. The standard disk diffusion antimicrobial susceptibility testing was used, with the Clinical and Laboratory Standards Institute (CLSI) threshold cutoffs for susceptibility of isolated uropathogens. Results Three hundred thirty cases were included with a median age of 47 years. Two hundred seventy-six (83.6%) were female. The most common isolated uropathogens were Escherichia coli in 201 (60.9%) cases and Klebsiella species in 46 (13.9%) cases. E. coli isolates showed the highest rates of susceptibility to nitrofurantoin (89.3%), cefixime (75%), and gentamicin (72.4%). Exposure to antibiotics in the past 3 months was a predictor of resistance to ciprofloxacin (OR: 2.8, 95% CI: 1.33–6.28), and older age was a predictor of resistance to TMP-SMX (OR: 2.1, 95% CI: 1.07–3.97) among E. coli isolates. Conclusion. E. coli and Klebsiella species accounted for about two-thirds of community-acquired uropathogens. In regard to the high susceptibility rates, nitrofurantoin was identified as the first-choice agent for empiric treatment of community-acquired cystitis, while cefixime and gentamicin might be the second-choice alternatives. Ciprofloxacin and TMP-SMX, on the other hand, cannot be considered appropriate agents for empiric therapy of community-acquired UTIs, particularly in those who had exposure to antibiotics in the past 3 months and the elderly.

Uropathogens antibiotic susceptibility as an indicator for the empirical therapy used for urinary tract infections: a retrospective observational study.

Background and Objectives:Urinary tract infection (UTI) is a common infection affects people of different ages. It is important to explore the antibiotics susceptibility of the bacterial agents to improve the empirical antibacterial prescription because of emerging of multi-drug resistant (MDR) bacteria.Materials and Methods:This is a retrospective observational study including 322 patients with UTI at the largest hospital at the center of Al-Basrah Governorate in the far south of Iraq from August 2018 to November 2019. Bacterial isolates from urine samples with significant bacteria were investigated by automated VITEK® 2 compact system to determine the causative bacteria and their antibiotics susceptibility.Results:Escherichia coli and Klebsiella pneumoniae were the first and second most frequent Gram-negative isolates, whereas Staphylococcus haemolyticus and Enterococcus faecalis were the first and second most frequent Gram-positive isolates. Fosfomycin, tigecycline, colistin, meropenem, imipenem, amikacin and nitrofurantoin had high susceptibility rates against Gram-negative isolates. Nitrofurantoin, tigecycline, daptomycin, teicoplanin, vancomycin and linezolid had a high effect against Gram-positive isolates.Conclusion:The leading causative isolates especially the most predominant Gram-negative isolates E. coli and K. pneumoniae show high resistance rates against important antibiotics including penicillin/β-lactamase inhibitors piperacillin/tazobactam, ceftazidime cefepime, ciprofloxacin, levofloxacin and trimethoprim/sulfamethoxazole which call for reconsidering them for treatment of UTI.

Antimicrobial Activity of Colistin Against Contemporary (2015 - 2017) P. aeruginosa and A. baumannii Isolates From a Chinese Surveillance Program.

ObjectiveTo investigate the incidence and susceptibilities of non-fermenting bacteria isolates from Chinese respiratory (RTI), intra-abdominal (IAI) and urinary tract (UTI) infections to antimicrobial agents between 2015 and 2017.MethodsIn total, 3,246 non-fermentative bacteria were collected from 21 hospitals and 9 hospital departments across 7 regions of China. A central testing laboratory was employed to determine antimicrobial susceptibilities using appropriate standards of interpretation.ResultsThe majority of the isolates were Acinetobacter baumannii (n = 1,360, 41.9%) and Pseudomonas aeruginosa (n = 1,341, 41.3%). Overall multidrug resistance (MDR) and carbapenem resistance (CR) rates of Acinetobacter baumannii were 80.1 and 78.7% with MDR and CR rates in RTIs, IAIs, and UTIs of 82.0 and 81.0%, 82.6 and 81.0% as well as 53.1 and 46.9%. Overall MDR and CR rates of Pseudomonas aeruginosa isolates were 36.2 and 38.9% with 41.8 and 44.3%, 29.3 and 36.1% as well as 24.2 and 20.2% MDR and CR rates in RTIs, IAIs, and UTIs. Overall susceptibility rates to imipenem, meropenem, amikacin, ciprofloxacin, cefepime and piperacillin-tazobactam were 21.1, 21.3, 33.0, 18.4, 19.2, and 19.6% for Acinetobacter baumannii and 56.5, 58.5, 88.4, 63.1, 63.1, and 55.63% for Pseudomonas aeruginosa isolates, whereas for colistin they were 95.7 and 94.6%, respectively. In all departments and regions of China, susceptibility rates of Pseudomonas aeruginosa and Acinetobacter baumannii isolates to colistin were constantly above 80%.ConclusionDue to the high MDR and CR rates for Pseudomonas aeruginosa and Acinetobacter baumannii, isolates obtained from RTIs, IAIs, and UTIs only maintained high susceptibility rates to colistin between 2015 and 2017.

In vitro activity of aztreonam/avibactam against a global collection of Klebsiella pneumoniae collected from defined culture sources in 2016 and 2017

ObjectivesThis study reports on the activity of aztreonam/avibactam (ATM-AVI) against a collection of Klebsiella pneumoniae collected in 2016 and 2017. MethodsNon-duplicate K. pneumoniae isolates were collected from four regions (Africa/Middle East, n = 785; Asia-Pacific, n = 1433; Europe, n = 4236; Latin America, n = 1499) and five culture sources (blood, n = 902; intra-abdominal, n = 992; urinary tract, n = 2148; skin and skin structure, n = 1409; lower respiratory tract, n = 2502). MICs were determined at a central laboratory using Clinical and Laboratory Standards Institute (CLSI) broth microdilution methodology. Susceptibility was determined using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. ResultsFor all culture sources, against all K. pneumoniae, the highest rates of susceptibility were seen for amikacin (>84%), ceftazidime/avibactam (>94%), colistin (>92%) and meropenem (>83%), and >99.9% of isolates were inhibited at an ATM-AVI MIC of ≤4 mg/L. Among meropenem-resistant (MEM-R, n = 583) and meropenem-resistant metallo-β-lactamase-negative (MEM-R-MBLN; n = 469) isolates, susceptibility was highest to ceftazidime/avibactam (79.9% and 99.4%, respectively) and colistin (67.2% and 62.7%, respectively). All MEM-R-MBLN isolates from blood, intra-abdominal, urinary tract and skin and skin structure sources, and all but one isolate from respiratory sources, were inhibited at an ATM-AVI MIC of ≤2 mg/L. Against the meropenem-resistant metallo-β-lactamase positive (MEM-R-MBLP; n = 114) isolates, susceptibility to colistin was between 75.0% (urinary tract isolates) and 93.3% (lower respiratory tract isolates). All MEM-R-MBLP isolates were inhibited at an ATM-AVI MIC of ≤0.5 mg/L. ConclusionsATM-AVI is active against K. pneumoniae isolates from a range of culture sources across Africa/Middle East, Asia-Pacific, Europe and Latin America. ATM-AVI also has activity against MEM-R-MBLN and MEM-R-MBLP isolates.

In vitro efficacy of ceftazidime-avibactam, aztreonam-avibactam and other rescue antibiotics against carbapenem-resistant Enterobacterales from the Arabian Peninsula

ObjectivesOur aim was to assess the susceptibility of carbapenem-resistant Enterobacterales (CRE) from the Arabian Peninsula to a broad spectrum of antibiotics, including fosfomycin, ceftazidime-avibactam, and aztreonam-avibactam. Methods1192 non-repeat CRE isolated in 2009–2017 from 33 hospitals in five countries of the Arabian Peninsula were tested. The minimum inhibitory concentration of 14 antibiotics was determined. Carbapenemase and 16S methylase genes were detected by PCR. Clonality was assessed by PFGE. ResultsThe highest rate of susceptibility was detected to aztreonam-avibactam (95.5%) followed by colistin (79.8%), fosfomycin (71.8%) and tigecycline (59.9%). Isolates co-producing two carbapenemases (12.4%) were the least susceptible. Aminoglycoside susceptibility was affected by the frequent production of a 16S methylase. Susceptibility to ceftazidime-avibactam was impacted by the high rate of metallo-beta-lactamase producers (46.3%), while aztreonam-avibactam resistance occurred mostly in clonally unrelated, carbapenemase non-producing Escherichia coli. ConclusionOf the currently available drugs: colistin, tigecycline, and ceftazidime-avibactam co-administered with aztreonam appear to be the most effective to treat CRE infections. However, the presence of non-clonal CRE isolates, in which avibactam does not lower the aztreonam MIC below the clinical breakpoint, is of notable concern. Based on the relatively high rate of fosfomycin susceptibility, it would be desirable to license parenteral fosfomycin in the region.

Antibiotic Sensitivity of Streptococcus Pneumoniae that Isolated from Different Pneumococcal Infections

During the period from June of 2018 to February 2019 (150) isolates of Streptococcus pneumoniae were isolated from 600 patients with clinical symptoms of Lower respiratory tract infections (LRTI) (pneumonia), otitis media and meningitis obtained from Baqubah Hospitals. The results showed that not only S. pneumoniae causes pneumonia and it can causes diseases other than pneumonia such as otitis media and meningitis but with less frequency. S. pneumoniae showed different susceptibilities towards antibiotics used in this study. The total susceptibility was (65.8%) and the total resistance was (34.2%). The highest pneumococcal susceptibility was showed to the cell wall inhibitors (44.4%) followed by protein synthesis inhibitors (28%) and quinolones (17.3%), and the lowest susceptibility was to folate antagonists with 0%. The highest rates of susceptibility was to penicillin (100%), chloramphenicol (86%), vancomycin (80%) and moderate rates of susceptibility to levofloxacin (90) 60%, linezolid (42.7) %, cefotaxime (40%), ofloxacin (40%) whereas there was a relatively lower susceptibility rate towards other antibiotics such as ampicillin, imipenem, amoxicillin, trimethoprim/sulfamethoxazole. Therefore, it should be avoided in the treatment in addition to tazobactam, amikacin, gentamicin, which had lowest rates susceptibility against S. pneumoniae. As a result, it required more research to identify new antibiotic or vaccine to reduce the risk of pneumococcal infection.

<p>Multidrug-Resistant <em>Acinetobacter baumannii</em> – The Modern Menace: A Retrospective Study in a Tertiary Hospital in Mangalore</p>

BackgroundMultidrug resistance in Acinetobacter baumannii is constantly on the rise. There has also been an increase in the morbidity and mortality of patients with infection by the same pathogen.AimThis study aimed to assess the patterns of antibiotic resistance exhibited by various clinical isolates of Acinetobacter baumannii, examine the risk factors associated, and investigate the prevalence of co-infecting pathogens and the clinical outcomes of the patients.Study DesignRetrospective cross-sectional study.Patients and MethodsReports of 100 isolates of Acinetobacter baumannii obtained from patients admitted in two tertiary hospitals were used for the study. Identification and determination of antibiotic resistance patterns were done using Vitek2. The presence of probable risk factors was noted. The pattern of clinical outcomes of the patients and the prevalence of co-infecting pathogens were analyzed. Data analysis was done using descriptive statistics.ResultsMore than 50% of isolates showed resistance independently to imipenem and meropenem. Higher rates of susceptibility were observed with tigecycline (55%). Isolates obtained from patients in the intensive care unit (ICU) showed resistance to a more number of antibiotics than those in the wards and operation theatre. Seventeen percent of the isolates were associated with a co-infecting pathogen such as Pseudomonas, Enterococcus, Klebsiella, 87% of the patients were discharged, 12% expired, and 1% were shifted. A positive correlation was found between the duration of hospital stay and number of antibiotics to which the isolate was resistant.ConclusionMultidrug resistance in Acinetobacter baumannii continues to be a menace. In this study, a large number of isolates exhibited resistance to carbapenems such as imipenem, meropenem, and ertapenem, thereby signifying the need for further research and the use of other antibiotics such as tigecycline, to which higher susceptibility was observed.

Prevalence, Resistance Rates, and Risk Factors of Pathogens in Routine Bile Cultures Obtained during Endoscopic Retrograde Cholangiography

Introduction and Objective: Acute cholangitis is a life-threatening condition. The early initiation of antibiotic therapy significantly impacts the course of disease. Only few data are available on distribution and resistance profiles of bile pathogens. Here, we report on an analysis of routinely acquired bile specimens and provide an overview of the prevalence, resistance rates, and risk factors for the presence of pathogens in bile. Methods: Bile cultures obtained from 388 endoscopic retrograde cholangiographies (ERCs) with corresponding clinical data were analysed in 208 patients. Results: The majority (84.8%) of cultures yielded positive for at least 1 organism. Abundance was highest for Enterococcus faecalis, Enterococcus faecium, and Escherichia coli. Multiresistant organisms were present in 14.9%. The initial antibiotic regimen was changed in 44.1%, which increased the length of hospital stay significantly (***p < 0.001). Pre-existing papillotomy (EPT) or biliary drainage was associated with higher frequency of bile pathogens (**p < 0.01) in a univariate analysis. Multivariate analysis confirmed these results for EPT and revealed significantly more positive results for pathogens, gram-negative bacteria, and fungi in patients with biliary drainage. Significant differences in the prevalence of pathogens were observed between relevant subgroups of ERC indications. The highest susceptibility rates were observed for linezolid and tigecycline in gram-positive bacteria and for meropenem and gentamicin in gram-negative bacteria. Conclusions: Our study provides a comprehensive analysis of the distribution, resistance profiles, and risk factors for the detection of bile pathogens. The frequent change in initial antibiotic treatment highlights the importance of routine bile culture and indicates that current schemas of empirical treatment might not cover the contemporary spectrum of pathogens in bile.

The potential risk of Schistosoma mansoni transmission by the invasive freshwater snail Biomphalaria straminea in South China.

Schistosomes infect more than 200 million people worldwide, and globally, over 700 million people are at risk of infection. The snail Biomphalaria straminea, as one of the intermediate hosts of Schistosoma mansoni, consecutively invaded Hong Kong in 1973, raising great concern in China. In this study, a malacological survey was conducted over a period of four years, and investigations were performed on the mechanism of susceptibility of B. straminea to S. mansoni. B. straminea was investigated in China from 2014 to 2018. Out of 185 investigated sites, 61 were positive for stages of black B. straminea (BBS), which shows pigmented spots. Twenty of the 61 sites were positive for red B. straminea (RBS), which is partially albino and red colored. Phylogenetic analyses based on cox1 and 18S rRNA sequences demonstrated that both phenotypes were clustered with Brazilian strains. No S. mansoni infections were detected in field-collected snail. However, in laboratory experiments, 4.17% of RBS were susceptible to a Puerto Rican strain of S. mansoni, while BBS was not susceptible. The highest susceptibility rate (70.83%) was observed in the F2 generation of RBS in lab. The density of RBS has increased from south to north and from west to east in Guangdong since 2014. Five tyrosinase tyrosine metabolism genes were upregulated in BBS. Transcriptome comparisons of RBS and BBS showed that ficolin, C1q, MASP-like, and membrane attack complex (MAC)/perforin models of the complement system were significantly upregulated in BBS. Our study demonstrated that B. straminea is widely distributed in Hong Kong and Guangdong Province, which is expanding northwards very rapidly as a consequence of its adaptation to local environments. Our results suggest that B. straminea from South China is susceptible to S. mansoni, implying the high potential for S. mansoni transmission and increased S. mansoni infection risk in China.

In vitro activity of ceftazidime-avibactam against Gram-negative isolates collected in 18 European countries, 2015–2017

BackgroundBetween 2015–2017, 21 850 Enterobacterales isolates and 6156 Pseudomonas aeruginosa (P. aeruginosa) isolates were collected by 77 centers in 18 European countries as part of the International Network for Optimal Resistance Monitoring (INFORM) study (which was included into the Antimicrobial Testing Leadership and Surveillance [ATLAS] study in 2018). MethodsA central reference laboratory performed antimicrobial susceptibility testing using broth microdilution panels according to Clinical and Laboratory Standards Institute guidelines. The presence of β-lactamases was confirmed using multiplex PCR assays. ResultsAmong Enterobacterales isolates, the highest rates of susceptibility were to ceftazidime-avibactam (99.0%; MIC90 0.5 mg/L), meropenem (96.3%), amikacin (95.2%), and imipenem (92.8%). All Enterobacterales organisms were highly susceptible to colistin (≥ 94.6%), apart from Proteus mirabilis, which is intrinsically resistant to colistin. Susceptibility rates among ceftazidime-resistant isolates were 95.7% for ceftazidime-avibactam and 87.9% for colistin, and 78.5% and 71.1%, respectively, among carbapenemase-positive isolates. Colistin was the only agent with activity against metallo-β-lactamases (100% susceptibility) among Enterobacterales and P. aeruginosa isolates. Overall susceptibility rates among P. aeruginosa were highest to colistin (99.5%) and ceftazidime-avibactam (92.3%), and were similar to ceftazidime-resistant isolates for colistin (98.9%) and reduced to 66.2% for ceftazidime-avibactam. Susceptibility rates among multidrug-resistant P. aeruginosa isolates were 98.9% to colistin and 71.7% to ceftazidime-avibactam. ConclusionsClinical isolates of Enterobacterales and P. aeruginosa collected from Europe, between 2015–2017, were highly susceptible to ceftazidime-avibactam, suggesting it is a useful alternative agent for patients whose treatment options may be limited. Persistent antimicrobial resistance requires continued surveillance and monitoring.

Multi-drug resistant and extended-spectrum \u03b2-lactamases producing bacterial uropathogens among pregnant women in Northwest Ethiopia

IntroductionAbove 80% of urinary tract infections are caused by enteric bacteria, which are known for years by their drug-resistant ability. Though the prevalence of drug-resistant strains is increasing in the world, it is not well known in low-income countries. The aim of this study was to assess the prevalence of Multi-drug resistance, Extended-spectrum β-lactamases production, and associated risk factors among pregnant women in Northwest Ethiopia.MethodsA hospital-based cross-sectional study was conducted among pregnant women from March to May 2017. A total of 384 clean-catch midstream urine sample was collected from study participants. Bacterial identification and drug susceptibility testing were done following standard microbiological techniques; Extended-spectrum β-lactamase production was screened using a disc diffusion test and confirmed by a combination disc test. The data were entered and analyzed by using SPSS version 20, and a p-value of less than 0.05 was considered as statistically significant.ResultThe overall prevalence of urinary tract infection was 15.9% (95% CI 12.8–20.1%). E. coli (49.2%), CoNS (27.9%), and S. aureus (18%) were the main uropathogens. The prevalence of MDR uropathogens was 60.65%. The prevalence of ESBLs production among cases caused by Enterobacteriaceae was 18.2%. The drug resistance rate of Gram-negative isolates was higher for ampicillin (90.9%), cephalothin (84.8%), and augmentin (57.6%). The drug nitrofurantoin showed the highest activity (100%) against Gram-negative isolates. Gram-positive isolates were showed low susceptibility to penicillin (89.3%) and cotrimoxazole (75%); however highest susceptibility rate for gentamicin (100%), amikacin (100%), and nitrofurantoin (98.36%) was recorded. Prior antibiotic therapy (AOR = 5.46, 95% CI 1.38–21.65) was a risk factor for the presence of multi-drug resistant bacteria.Conclusion and recommendationThe multi-drug resistance prevalence was high among uropathogen, thus treatment of urinary tract infection during pregnancy; should be based on the antibacterial susceptibility testing result. The isolation of drug-resistant strains like Extended-spectrum β-lactamases in this study calls for the need of periodic and continuous follow-up of antibiotic usage among pregnant women. Nitrofurantoin, gentamicin, amikacin, and ciprofloxacin/norfloxacin showed higher activity against bacterial uropathogen.

An exploratory analysis of demography and movement patterns of dogs: New insights in the ecology of endemic Rocky Mountain-Spotted Feverin Mexicali, Mexico.

An outbreak of Rocky Mountain spotted fever (RMSF) transmitted by the brown dog tick (Rhipicephalus sanguineus sensu lato) has emerged as a major human and animal health concern in Mexicali, Mexico. Due to high rates of brown dog tick infestation, susceptibility, and association with humans, dogs serve as sentinels and have a key role in the ecology of RMSF. A cross-sectional household questionnaire study was conducted in six rural and urban locations to characterize dog ecology and demography in RMSF high-and low-risk areas of Mexicali. In addition, we tracked movement patterns of 16 dogs using a GPS data logger. Of 253 households, 73% owned dogs, and dog ownership tended to be higher in high-risk areas, with a mean dog:human ratio of 0.43, compared with 0.3 in low-risk areas. Dogs in high-risk areas had higher fecundity and roamed more, but the dog density and numbers of free-roaming dogs were comparable. There was a higher proportion of younger dogs and lower proportion of older dogs in high-risk areas. The high proportion of immunologically naïve puppies in high risk areas could result in a lack of herd immunity leading to a more vulnerable dog and human population. The marked increase of space use of free-roaming dogs in high-risk areas suggests that unrestrained dogs could play an important role in spreading ticks and pathogens. As means to limit RMSF risk, practical changes could include increased efforts for spay-neuter and policies encouraging dog restraint to limit canine roaming and spread of ticks across communities; due to dog density is less impactful such policies may be more useful than restrictions on the number of owned dogs.

Evaluation of the synergy of ceftazidime/avibactam in combination with colistin, doripenem, levofloxacin, tigecycline, and tobramycin against OXA-48 producing Enterobacterales

This study aims to analyze the effect of ceftazidime/avibactam plus various antibiotics against OXA-48-producing Enterobacterales isolated from Intensive Care Units. Seventy-four non-duplicate OXA-48-producing Enterobacterales isolates were screened for their MICs by the microbroth dilution method. The in-vitro bactericidal and synergistic activities of ceftazidime/avibactam alone or in combination with other antibiotics were determined by time-kill curve assays. According to our results, colistin was the most active drug with higher susceptibility rates in the strains. Colistin, levofloxacin, tobramycin, and doripenem showed bactericidal effects against different isolates. The best synergistic interactions were achieved with ceftazidime/avibactam + colistin, ceftazidime/avibactam + tobramycin, and ceftazidime/avibactam + tigecycline against studied strains used at 1xMIC concentrations at 24 h. No antagonism was observed against studied OXA-48-producing Enterobacterales strains.The findings of this study suggest that ceftazidime/avibactam plus colistin, tobramycin, or tigecycline were more effective against OXA-48-producing Enterobacterales strains. This combination therapy could be an alternative antibiotic therapy for carbapenemase-producing Enterobacterales strains.

In vitro activity of ceftazidime/avibactam and comparators against Gram-negative bacterial isolates collected from Latin American centres between 2015 and 2017

ObjectivesWe report the in vitro activity of ceftazidime/avibactam and comparators against 7729 Enterobacterales isolates and 2053 Pseudomonas aeruginosa isolates collected from six Latin American countries between 2015 and 2017.MethodsA central reference laboratory performed antimicrobial susceptibility testing using broth microdilution panels according to CLSI guidelines. The presence of β-lactamases was confirmed using multiplex PCR assays.ResultsSusceptibility rates among Enterobacterales were highest for ceftazidime/avibactam (99.3%, MIC90 = 0.5 mg/L), meropenem (95.4%, MIC90 = 0.12 mg/L) and amikacin (93.5%, MIC90 = 8 mg/L). High susceptibility rates were observed for ceftazidime/avibactam in all six countries. The majority of carbapenemase-positive isolates among Enterobacterales (N = 366, 4.7%) were susceptible to ceftazidime/avibactam (86.9%), colistin (76.8%) and amikacin (60.9%); MBL-positive isolates (N = 49, 0.6%) were susceptible only to colistin (79.6%), with a minority susceptible to amikacin (49.0%), aztreonam and levofloxacin (both 30.6%). Highest rates of susceptibility among P. aeruginosa isolates were for colistin (99.2%) and ceftazidime/avibactam (86.6%), with rates of susceptibility to all other agents being <80.0%. MDR P. aeruginosa isolates (N = 712, 34.7%) had a high rate of susceptibility to colistin (98.9%); the rate of susceptibility to ceftazidime/avibactam was 61.4% and <50.0% to all other comparator agents. A total of 235 (11.4%) isolates of P. aeruginosa were carbapenemase positive and 148 (7.2%) were MBL positive; both subsets had high rates of susceptibility to colistin (98.3% and 100%, respectively).ConclusionsCeftazidime/avibactam susceptibility rates in Latin American countries are stable and high; ceftazidime/avibactam can be an appropriate treatment for patients with infections caused by Enterobacterales or P. aeruginosa and for whom treatment options may be limited.

Ecogenetics of antibiotic resistance in Listeria monocytogenes.

The acquisition process of antibiotic resistance in an otherwise susceptible organism is shaped by the ecology of the species. Unlike other relevant human pathogens, Listeria monocytogenes has maintained a high rate of susceptibility to the antibiotics used for decades to treat human and animal infections. However, L. monocytogenes can acquire antibiotic resistance genes from other organisms' plasmids and conjugative transposons. Ecological factors could account for its susceptibility. L. monocytogenes is ubiquitous in nature, most frequently including reservoirs unexposed to antibiotics, including intracellular sanctuaries. L. monocytogenes has a remarkably closed genome, reflecting limited community interactions, small population sizes and high niche specialization. The L. monocytogenes species is divided into variants that are specialized in small specific niches, which reduces the possibility of coexistence with potential donors of antibiotic resistance. Interactions with potential donors are also hampered by interspecies antagonism. However, occasional increases in population sizes (and thus the possibility of acquiring antibiotic resistance) can derive from selection of the species based on intrinsic or acquired resistance to antibiotics, biocides, heavy metals or by a natural tolerance to extreme conditions. High-quality surveillance of the emergence of resistance to the key drugs used in primary therapy is mandatory.

Detection of Biofilm Formation and Antibiotic Resistance in Klebsiella Oxytoca and Klebsiella Pneumoniae from Animal Origin Foods

Biofilms are surface-attached microbial communities with distinct properties, which have a tremendous impact on our health and food safety. The study was aimed to detect biofilm formation and antibiotic resistance by Klebsiella oxytoca and Klebsiella pneumoniae from animal origin foods. In this study100 food samples were examined for the presence of Klebsiella oxytoca, Klebsiella pneumoniae, and other Enterobacteriaceae family members. In this study, 19 Klebsiella oxytoca and 5 Klebsiella pneumoniae isolates were isolated from cheese and minced meat samples using standard biochemical tests and identification kit. Biofilm formation in these isolates was detected by using microplate, Congo red agar, and tube adherence methods. Antibiotic susceptibility testing was performed using the disk diffusion method on Muller-Hinton agar. Using a microplate method strong biofilm formation was observed in 16 (84%) and 5 (100%) isolates of Klebsiella oxytoca and Klebsiella pneumoniae after 24 hours of incubation on Tryptic Soy Broth medium containing 2% of glucose respectively. After 24 and 48 hours of incubation on Tryptic Soy Broth without glucose strong biofilm formation was detected in 10 (52.6%) and 2 (40%) isolates of Klebsiella oxytoca and Klebsiella pneumoniae respectively. After 24 hours of incubation on Congo red agar 14 (73.7%) and 3 (60%), isolates of Klebsiella oxytoca and Klebsiella pneumoniae were slime factor positive respectively. In tube adherence method 13 (68.4%) and 4 (80%), isolates of Klebsiella oxytoca and Klebsiella pneumoniae were seen to have adhered strongly after 24 hours of incubation on Tryptic Soy Broth medium containing 2% of glucose. In general, strong biofilm formation by these strains was seen on Tryptic Soy Broth medium when supplemented with glucose. Among all the Klebsiella oxytoca, the highest rates of susceptibility were seen toward Trimethoprim-Sulfamethoxazole (100%) and Imipenem (94.7%) followed by Chloramphenicol (73.7%) and gentamicin (68.4%). Among 19 Klebsiella oxytoca isolates, the highest rates of resistance were seen in streptomycin (73.7%) and Kanamycin (73.7%) followed by ampicillin (63.2%). The majority of Klebsiella pneumoniae isolates were resistant to Kanamycin (80%) and Streptomycin (80%) followed by Amikacin (60%). On the other hand, 80% of Klebsiella pneumoniae were susceptible to imipenem, chloramphenicol, Trimethoprim-Sulfamethoxazole, and cefotaxime. Generally, majority of Klebsiella oxytoca, and Klebsiella pneumoniae isolates showed strong biofilm production on different growth conditions and majority of the isolates were also resistance for antibiotics. Therefore, biofilm production by these nosocomial bacteria has an implication public health and pave the way for increased resistance of biofilm-associated organisms to antimicrobial agents.

Identification of Fosfomycin Heteroresistance Among Multidrug-Resistant Enterobacteriaceae Urinary Isolates

Fosfomycin is an orally bioavailable bactericidal agent which concentrates significantly in urine and is being increasingly prescribed for patients with Multidrug Resistant Enterobacteriaceae (MDRE) urinary isolates. According to the Clinical and Laboratory Standards Institute (CLSI), disc diffusion (DD) and agar dilution (AD) are the standards for fosfomycin susceptibility testing for urinary Escherichia coli and Enterococcus faecalis isolates, whereas the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines suggest both AD and broth microdilution (BD), but not DD. A prospective study was done in the Department of Microbiology in a tertiary care teaching hospital in Kolkata. MDRE urinary isolates that were resistant to oral and third-generation cephalosporins, either ciprofloxacin or levofloxacin and either of cotrimoxazole or nitrofurantoin were included in the study and tested further for fosfomycin. DD was carried out on Mueller-Hinton agar (MHA) supplemented with 25 μ/ml G6P with 50 and 200 μg discs. E-test was carried out on the same medium with drug concentrations ranging from 0.064 to 1024 μ/ml. Broth dilution was carried out on G6P supplemented Mueller Hinton broth with drug concentrations ranging from 0.25 to 1024 μ/ml. A total of 723 urine samples were obtained in a 2-month period, which yielded 79 Enterobacteriaceae, out of which 30 were MDRE. About 26 (86.67%) of these isolates were susceptible to fosfomycin by CLSI criteria and 25 (83.33%) by EUCAST criteria for minimum inhibitory concentration (MIC) by E-test and broth dilution. Only 4 (13.33%) were resistant to fosfomycin by DD. However, heteroresistant colonies were found among 21 (70%) isolates by E-test. None of these were picked up by DD or BD. The MIC of fosfomycin was between 0.25 and 512 μ/ml. These heteroresistant colonies when further subjected to E-test and BD showed resistance with MIC ≥512 μg/ml, depicting prevalence of heteroresistance. E-test can be used as a simple and effective screening method for identifying the fosfomycin heteroresistance and in turn changing the myth of the so high susceptibility rates among MDRE.

The study of professional burnout syndrome in specialists of the department of anaesthesiology and intensive care

Objective was to determine the presence and the main manifestations of professional burnout syndrome among intensive care doctors and nurses from the department of anesthesiology and intensive care. Material and methods. Resuscitators and secondary medical staff were asked to pass a questionnaire, which included a survey by V.V. Boyko «Emotional burnout», a test by C. Spielberger in the modification Y.A. Hanin, the technique of Munsterberg. Results and discussion. Professional burnout syndrome is typical for 55 % of resuscitators and 35 % of mid-level medical staff of the department of anaesthesiology and intensive care of the pediatric University clinic. As for the respondents of the first group, the presence of the «resistance» phase is characteristic, while the second group has the «resistance» and «exhaustion» phases. According to the Spielberger scale, both groups have a middle degree of situational and personal anxiety. The Munsterberg method found that selectiveness and concentration of attention before and after the daily shift is more decreased in resuscitators. Conclusion. High rates of susceptibility of specialists of the department of anaesthesiology and intensive care to the formation of professional burnout syndrome, which affects their psychological health, were established. It is necessary to develop appropriate measures to prevent this occurrence.