Antimicrobial Resistance In Clinical Isolates Research Articles

Comparison of integron mediated antimicrobial resistance in clinical isolates of Escherichia coli from urinary and bacteremic sources

BackgroundAntimicrobial resistance (AMR) is a global threat driven mainly by horizontal gene transfer (HGT) mechanisms through mobile genetic elements (MGEs) including integrons. The variable region (VR) of an integron can acquire or excise gene cassettes (GCs) that confer resistance to antibiotics based on the selection pressure. Escherichia coli plays a significant role in the genetic transfer of resistance determinants to other Gram-negative bacteria. Current study is aimed to detect and compare integron-mediated resistance in clinical isolates of E. coli. Unique isolates of E. coli from urine or blood cultures were studied for their antimicrobial resistance patterns and integrons were detected using polymerase chain reaction assays followed by Sanger sequencing of GCs.ResultsDuring the study period, a total of 470 E. coli isolates were obtained, 361 (76.8%) from urinary and 109 (23.1%) from bacteremic sources. Class 1 integrons were detected in 66 (18.2%) and 26 (23.8%) isolates respectively. Urinary isolates of E. coli harbouring Class 1 integrons demonstrated significantly higher rates of resistance (p < 0.05) for most antibiotics (12/16, 75%) compared to integron negative isolates. Although not statistically significant, similar differences were observed in bacteremic isolates. Among the urinary isolates, 27 (40.9%) had a VR, in which the most common GC array detected was DfrA17-AadA5 (n = 14), followed by DfrA5 (n = 4) and DfrA12 (n = 3). Among bacteremic isolates, only 4 (15.3%) had a VR, all of which were carrying DfrA17. The detected GC array correlated with the respective isolates’ phenotypic resistance patterns.ConclusionWe found a strong correlation between integron positivity and trimethoprim resistance among E. coli from urinary sources. Although higher rates of resistance were observed in bacteremic isolates, they mostly carried empty integrons.

The Antibacterial Effect of Tinospora Cordifolia (Guduchi) and Its Role in Combating Antimicrobial Resistance.

Tinospora cordifolia, often known as "Guduchi," has a variety of medicinal characteristics, including those that are anti-diabetic, ant-iinflammatory, anti-periodic, anti-arthritic, anti-oxidant, anti-allergic, and anti-stress. Drug development projects face significant obstacles because of the rapid rise in antimicrobial drug resistance in the world healthcare system and the introduction of multidrug-resistant (MDR) strains. In order to combat the MDR infections isolated from patients' bodies, the current study was conducted to evaluate and investigate the antibacterial capabilities of Tinospora cordifolia. Using the agar well diffusion method, Tinospora cordifolia extracts (aqueous, chloroform, and ethanol) were tested for their antibacterial effectiveness against 30 MDR pathogens, and the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay was used to determine the minimal inhibitory concentration. To determine whether there were any medicinally useful and significant bioactive ingredients in the plant extract, phytochemical analysis was performed. In comparison to the aqueous extract which had little effect, the antibacterial activity of ethanol and chloroform extracts exhibited a potential antimicrobial effect against most of the tested bacterial isolates. Phytochemical analysis of Tinospora cordifolia extract showed alkaloids, carbohydrates, phytosterols, saponins, tannins, proteins, flavonoids, and terpenoids. Our findings show that Tinospora cordifolia plays a potential role in combating the antimicrobial resistance of clinical isolates.

Changing Trends of Antimicrobial Resistance in Clinical Isolates Yielded from Lower Respiratory Tract Specimens of ICU Patients-A Two-Year Study

Objective: To determine changing trends in antimicrobial resistance among Gram-negative bacterial isolates yielded in lower respiratory tract specimens in intensive care settings.&#x0D; Study Design: Cross-sectional study&#x0D; Place and Duration of Study: Armed Forces Institute of Pathology, Rawalpindi Pakistan, Jul 2018 to Jun 2020.&#x0D; Methodology: The study was carried out on 819 isolates from lower respiratory tract specimens collected from ICUs of multiple centres all over Pakistan. The antimicrobial susceptibility testing was performed according to performance standards provided by CLSI and EUCAST. Antimicrobial resistance trends were analyzed.&#x0D; Results: In Acinetobacter baumannii, resistance increased against Carbapenems (92% to 97.4%) and Polymyxins (0% to 5.3%).Pseudomonas aeruginosa showed increasing resistance, with Imipenem (33.3% to 46.9%), Meropenem (27.3% to 43.6%) and Polymyxin (0% to 3%). In Klebsiella pneumoniae, the resistance against Carbapenems rose from 60.5% to 79.2%, for Imipenem 68.4% to 83% for Meropenem. Polymyxin resistance was much higher in K. pneumoniae (increasing from 22% to 24.5%). In Escherichia coli, resistance increased from 23.5% to 41.7% for Imipenem 35.5% to 50% for Meropenem, and 0% to 8.3% for Polymyxins, whereas Tigecycline showed decreasing resistance trend. Other antimicrobials tested showed increasing resistance as well.&#x0D; Conclusion: Antimicrobial resistance is emerging so rapidly that the post-antibiotic era is approaching sooner than later. Extensive and up-to-date insight regarding antimicrobial resistance rates and trends against significant pathogens is required to deal with this emerging dilemma.

Bacterial Species and Antimicrobial Resistance of Clinical Isolates from Pediatric Patients in Yangon, Myanmar, 2020.

Antimicrobial resistance (AMR) is a concern in medical care for children who have high burden of infectious diseases. We investigated the prevalence of bacterial species and their susceptibility to antimicrobials of 1019 clinical isolates from pediatric patients in a tertiary-care hospital in Yangon, Myanmar for one-year period (2020). The most frequently recovered species was Escherichia coli, followed by Klebsiella pneumoniae and Staphylococcus aureus, all of which accounted for 43% of clinical isolates, while 25% of isolates comprised non-fermenter, including Pseudomonas sp. and Acinetobacter sp. Phenotypically determined ESBL (extended-spectrum beta-lactamase)-positive rates in E. coli, K. pneumoniae, and Enterobacter sp. were 82%, 88%, and 65%, respectively. High rates of multiple drug resistance were noted for E. coli (84%), K. pneumoniae (81%), and Acinetobacter sp. (65%), associated with carbapenem resistance in 48%, 42%, and 59% of isolates, respectively. In contrast, S. aureus isolates exhibited low resistance rates (<30%) to most of antimicrobials, with 22% being resistant to oxacillin/cefoxitin. Fluoroquinolone resistance was found in most of bacterial species with different prevalence rates. The present study revealed the current status on prevalence of bacterial species causing infections in pediatric patients in Myanmar, highlighting the significance to monitor AMR among children.

Phenotypic and genotypic characterization of antimicrobial resistance in clinical isolates of Vibrio cholerae over a decade (2002-2016)

PurposeEmergence and spread of resistance among Vibrio cholerae have become a global public health problem. In India, no consolidated data is available on antimicrobial susceptibility patterns and antibiotic resistance genes. MethodsA total of 110 representative isolates obtained over a period of 14 years were included. Antimicrobial susceptibility was tested by disc diffusion and micro broth dilution. Presence of 13 antimicrobial resistance genes was ascertained by using PCR. ResultsAntimicrobial resistance fluctuated for most of the antibiotics. Resistance to cotrimoxazole in our study was 92.72% and the SXT element was present in all isolates. Resistance to nalidixic acid, tetracycline, and cefotaxime was found to be 98.18%, 7.27%, and 10.9% respectively. Resistance to ampicillin saw a fluctuating trend with a recent fall. Resistance to ciprofloxacin and azithromycin was 12.72% and 29% by MIC. blaTEM was the most common ESBL gene (94.5%). Other were blaCMY (26.36%) and blaNDM (2.7%). We report blaCTX-M-15 and blaOXA-48 and ermB for the first time in the world. Newer antimicrobials like prulifloxacin and rifaximin were tested for the first time from India. ConclusionsOur study has shown very high levels of resistance to older antibiotics and the emergence of resistance to some of the newer classes of antibiotics. There is an urgent need for increased surveillance studies, rational use of the antimicrobials and preventive measures to control the disease.

Prevalence of antimicrobial resistance in Gram-negative clinical isolates from a major secondary hospital in Kuwait: a retrospective descriptive study.

Building an antimicrobial resistance (AMR) surveillance system in a country requires analysis of available data on AMR in clinical isolates. This study's objective was to determine the AMR prevalence of Gram-negative bacterial (GNB) isolates cultured from clinical specimens at a major general hospital in Kuwait. A retrospective descriptive study was conducted on AMR profiles of GNB clinical isolates (n=5290) between January and December 2018. Data were extracted from the laboratory information system in the hospital. The GNB organisms (i.e., Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) were isolated from five main locations at the hospital (i.e., intensive care units [ICUs], surgical wards, medical wards, pediatric wards, and outpatient polyclinics). Overall, high AMR prevalence (>50%) against ampicillin, cefuroxime, cefotaxime, ceftazidime, ciprofloxacin, and trimethoprim/sulfamethoxazole, were observed across the GNB organisms. However, low resistance prevalence (<10%) were observed against amikacin, ertapenem, meropenem, and piperacillin/tazobactam. In general, AMR prevalence in E. coli isolates from ICU, medical and surgical wards was significantly (p<0.05) higher compared to other locations, whereas, AMR prevalence in P. aeruginosa isolates from pediatric ward was higher (p<0.05) compared to other locations. The overall multidrug resistance (MDR) prevalence was 38.7% (95% CI: 37.4-40.0). The highest MDR prevalence was among E. coli isolates from respiratory specimens (48%); wounds, bones, or other tissues (47.7%); and body fluids (47.1%). Similarly, MDR prevalence in K. pneumoniae, P. aeruginosa, and A. baumannii isolated from respiratory specimens was significantly (p<0.05) higher compared to other specimen types. The most frequent MDR phenotypes in the four GNB organisms and across the different specimen types included three antimicrobial drug classes: penicillins, cephalosporins, and fluroquinolones. Our findings demonstrate high AMR prevalence among common Gram-negative bacteria at this major hospital. Monitoring data on antimicrobial susceptibility of common bacterial organisms is critical for assessing trends in AMR at hospitals and for informing policy decisions.

Assessment of animal diseases caused by bacteria resistant to antimicrobials: cattle.

In this opinion, the antimicrobial resistant bacteria responsible for transmissible diseases that constitute a threat to the health of cattle have been assessed. The assessment has been performed following a methodology based on information collected by an extensive literature review and expert judgement. Details of the methodology used for this assessment are explained in a separate opinion. A global state of play on antimicrobial resistance in clinical isolates of Escherichia coli (non‐VTEC), Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Pasteurella multocida, Mannheimia haemolytica, Histophilus somni, Mycoplasma bovis, Moraxella bovis, Fusobacterium necrophorum and Trueperella pyogenes is provided. Among those bacteria, EFSA identified E. coli and S. aureus with ≥ 66% certainty as being the most relevant antimicrobial resistant bacteria in cattle in the EU based on the available evidence. The animal health impact of these most relevant bacteria, as well as their eligibility for being listed and categorised within the animal health law framework will be assessed in separate scientific opinions.

Assessment of animal diseases caused by bacteria resistant to antimicrobials: sheep and goats.

In this opinion, the antimicrobial‐resistant bacteria responsible for transmissible diseases that constitute a threat to the health of sheep and goats have been assessed. The assessment has been performed following a methodology based on information collected by an extensive literature review and expert judgement. Details of the methodology used for this assessment are explained in a separate opinion. A global state of play on antimicrobial resistance in clinical isolates of Staphylococcus aureus, Escherichia coli (non‐VTEC), Pseudomonas aeruginosa, Dichelobacter nodosus, Moraxella ovis, Mannheimia haemolytica, Pasteurella multocida, Mycoplasma ovipneumoniae, Mycoplasma agalactiae, Trueperella pyogenes, Streptococcus uberis, Bibersteinia trehalosi, Campylobacter fetus, Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum, Fusobacterium necrophorum is provided. Among those bacteria, EFSA identified E. coli with ≥ 66% certainty as being the most relevant antimicrobial‐resistant bacteria in sheep and goat in the EU based on the available evidence. The animal health impact of these most relevant bacteria, as well as their eligibility for being listed and categorised within the animal health law framework will be assessed in separate scientific opinions.

Assessment of animal diseases caused by bacteria resistant to antimicrobials: rabbits.

In this opinion, the antimicrobial‐resistant bacteria responsible for transmissible diseases that constitute a threat to the health of farmed rabbits have been assessed. The assessment has been performed following a methodology based on information collected through an extensive literature review and expert judgement. Details of the methodology used for this assessment are explained in a separate opinion. A global state of play on antimicrobial resistance in clinical isolates of Pasteurella multocida, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bordetella bronchiseptica, Clostridium difficile, Clostridium perfringens and Clostridium spiroforme is provided. Among these bacteria, none were identified as being the most relevant antimicrobial‐resistant bacteria in rabbits in the EU due to the very limited scientific evidence available.

Australian Gonococcal Surveillance Programme Annual Report, 2020.

The Australian Gonococcal Surveillance Programme (AGSP), established in 1981, has continuously monitored antimicrobial resistance in clinical isolates of Neisseria gonorrhoeae for more than 40 years. In 2020, a total of 7,222 clinical isolates of gonococci from patients in the public and private sectors, in all jurisdictions, were tested for in vitro antimicrobial susceptibility by standardised methods. Current treatment recommendations for gonorrhoea, for the majority of Australia, continues to be dual therapy with ceftriaxone and azithromycin. In 2020, decreased susceptibility (DS) to ceftriaxone (minimum inhibitory concentration [MIC] value ≥ 0.06 mg/L) was found nationally in 0.9% of isolates. There was one isolate, reported from Victoria in 2020, that was resistant to ceftriaxone (MIC value ≥ 0.25 mg/L). Resistance to azithromycin (MIC value ≥ 1.0 mg/L) was found nationally in 3.9% of N. gonorrhoeae isolates, continuing a downward trend observed and reported since 2017. Isolates with high-level resistance to azithromycin (MIC value ≥ 256 mg/L) are identified sporadically in Australia; in 2020, there was one such isolate reported in Queensland. In 2020, penicillin resistance was found in 27% of gonococcal isolates nationally, and ciprofloxacin resistance in 36%; however, there is considerable variation by jurisdiction. In some remote settings, penicillin resistance remains low, and this drug continues to be recommended as part of an empiric therapy strategy. In 2020, in remote Northern Territory, no penicillin resistance was reported, and in remote Western Australia 5/116 of gonococcal isolates (4.3%) were penicillin resistant. There was one ciprofloxacin-resistant isolate reported from remote Northern Territory, and ciprofloxacin resistance rates remain comparatively low in remote Western Australia (4/116; 3.4%).

Antimicrobial Resistance and the Spectrum of Pathogens in Dental and Oral-Maxillofacial Infections in Hospitals and Dental Practices in Germany.

Data on microbiological profiles in odontogenic infections are scarce. This study aimed to analyze the spectrum of pathogens and antimicrobial resistance in clinical isolates from dental and oral-maxillofacial clinical settings in Germany. We analyzed 20,645 clinical isolates (dental practices: n = 5,733; hospitals: n = 14,912) from patients with odontogenic infections using data (2012–2019) from the German Antimicrobial-Resistance-Surveillance (ARS) system. A total of 224 different species from 73 genera were found in clinical isolates from dental practices, and 329 different species from 97 genera were identified in isolates from hospital patients. In both hospitals and dental practices Streptococcus spp. (33 and 36%, respectively) and Staphylococcus spp. (21 and 12%, respectively) were the most frequently isolated microorganisms. In Streptococcus spp. isolates from hospitals, penicillin and aminopenicillin resistance proportions were 8.0% (95%CI 4.7–14.9%) and 6.9% (95%CI 4.7–9.9%), respectively. Substantially lower resistance proportions of penicillin and aminopenicillin were observed in dental practices [2.6% (95%CI 1.4–4.7%) and 2.1% (95%CI 1.1–4.0%), respectively]. Among Staphylococcus aureus isolates from hospital patients methicillin resistance proportions were 12.0% (95%CI 9.7–14.8%), which was higher than in isolates from dental practices (5.8% (95%CI 4.1–8.1%)]. High clindamycin and macrolide resistance proportions (>17%) were observed in Streptococcus spp. and Staphylococcus aureus isolates. In Klebsiella spp. isolates carbapenem resistance proportions were <1%. In sum, substantial antibiotic resistance was observed in isolates from odontogenic infections, which calls for strengthened efforts in antibiotic stewardship and infection prevention and control measures in both hospitals and dental practices.

Population-level faecal metagenomic profiling as a tool to predict antimicrobial resistance in Enterobacterales isolates causing invasive infections: An exploratory study across Cambodia, Kenya, and the UK.

BackgroundAntimicrobial resistance (AMR) in Enterobacterales is a global health threat. Capacity for individual-level surveillance remains limited in many countries, whilst population-level surveillance approaches could inform empiric antibiotic treatment guidelines.MethodsIn this exploratory study, a novel approach to population-level prediction of AMR in Enterobacterales clinical isolates using metagenomic (Illumina) profiling of pooled DNA extracts from human faecal samples was developed and tested. Taxonomic and AMR gene profiles were used to derive taxonomy-adjusted population-level AMR metrics. Bayesian modelling, and model comparison based on cross-validation, were used to evaluate the capacity of each metric to predict the number of resistant Enterobacterales invasive infections at a population-level, using available bloodstream/cerebrospinal fluid infection data.FindingsPopulation metagenomes comprised samples from 177, 157, and 156 individuals in Kenya, the UK, and Cambodia, respectively, collected between September 2014 and April 2016. Clinical data from independent populations included 910, 3356 and 197 bacterial isolates from blood/cerebrospinal fluid infections in Kenya, the UK and Cambodia, respectively (samples collected between January 2010 and May 2017). Enterobacterales were common colonisers and pathogens, and faecal taxonomic/AMR gene distributions and proportions of antimicrobial-resistant Enterobacterales infections differed by setting. A model including terms reflecting the metagenomic abundance of the commonest clinical Enterobacterales species, and of AMR genes known to either increase the minimum inhibitory concentration (MIC) or confer clinically-relevant resistance, had a higher predictive performance in determining population-level resistance in clinical Enterobacterales isolates compared to models considering only AMR gene information, only taxonomic information, or an intercept-only baseline model (difference in expected log predictive density compared to best model, estimated using leave-one-out cross-validation: intercept-only model = -223 [95% credible interval (CI): -330,-116]; model considering only AMR gene information = -186 [95% CI: -281,-91]; model considering only taxonomic information = -151 [95% CI: -232,-69]).InterpretationWhilst our findings are exploratory and require validation, intermittent metagenomics of pooled samples could represent an effective approach for AMR surveillance and to predict population-level AMR in clinical isolates, complementary to ongoing development of laboratory infrastructures processing individual samples.

Inverse correlation between biofilm production efficiency and antimicrobial resistance in clinical isolates of Pseudomonas aeruginosa

This study assessed the correlation between biofilm formation in Pseudomonas aeruginosa strains with both the level of antibiotic resistance, and the number of virulence- and biofilm-related genes encoded. A total of sixty-six, non-replicate and prospectively collected P. aeruginosa strains were identified and tested. Potential ampD mutations that may impose resistance to extended-spectrum β-lactam (ESBL) agents were further explored. Of the sixty-six tested isolates, 40 demonstrated the multidrug resistance (MDR) phenotype, while twenty-six were non-MDR strains. An inverse correlation was observed between antibiotic resistance and the potential capacity to form biofilms. In addition, no correlation was observed between novel ampD mutations and the tendency for MDR isolates to acquire a β-lactam-resistant phenotype. The present study emphasizes the need for enhanced infection preventive measures in various hospital units, since both MDR and non-MDR P. aeruginosa isolates exhibited a high level of biofilm-forming capacity and the presence of virulence-associated genes.

Australian Gonococcal Surveillance Programme Annual Report, 2020.

The Australian Gonococcal Surveillance Programme (AGSP), established in 1981, has continuously monitored antimicrobial resistance in clinical isolates of Neisseria gonorrhoeae for more than 40 years. In 2020, a total of 7,219 clinical isolates of gonococci from patients in the public and private sectors, in all jurisdictions, were tested for in vitro antimicrobial susceptibility by standardised methods. Current treatment recommendations for gonorrhoea, for the majority of Australia, continues to be dual therapy with ceftriaxone and azithromycin. In 2020, decreased susceptibility (DS) to ceftriaxone (minimum inhibitory concentration [MIC] value ≥ 0.06 mg/L) was found nationally in 0.9% of isolates. There was one isolate, reported from Victoria in 2020, that was resistant to ceftriaxone (MIC value ≥ 0.25 mg/L). Resistance to azithromycin (MIC value ≥ 1.0 mg/L) was found nationally in 3.9% of N. gonorrhoeae isolates, continuing a downward trend observed and reported since 2017. Isolates with high-level resistance to azithromycin (MIC value ≥ 256 mg/L) are identified sporadically in Australia; in 2020, there was one such isolate reported in Queensland. In 2020, penicillin resistance was found in 27% of gonococcal isolates nationally, and ciprofloxacin resistance in 36%; however, there is considerable variation by jurisdiction. In some remote settings, penicillin resistance remains low, and this drug continues to be recommended as part of an empiric therapy strategy. In 2020, in remote Northern Territory, no penicillin resistance was reported, and in remote Western Australia 5/116 of gonococcal isolates (4.3%) were penicillin resistant. There was one ciprofloxacin-resistant isolate reported from remote Northern Territory, and ciprofloxacin resistance rates remain comparatively low in remote Western Australia (4/116; 3.4%).

High Levels of Antibiotic Resistance in Isolates From Diseased Livestock.

Overuse of antimicrobials in livestock health and production beyond therapeutic needs has been highlighted in recent years as one of the major risk factors for the acceleration of antimicrobial resistance (AMR) of bacteria in both humans and animals. While there is an abundance of reports on AMR in clinical isolates from humans, information regarding the patterns of resistance in clinical isolates from animals is scarce. Hence, a situational analysis of AMR based on clinical isolates from a veterinary diagnostic laboratory was performed to examine the extent and patterns of resistance demonstrated by isolates from diseased food animals. Between 2015 and 2017, 241 cases of diseased livestock were received. Clinical specimens from ruminants (cattle, goats and sheep), and non-ruminants (pigs and chicken) were received for culture and sensitivity testing. A total of 701 isolates were recovered from these specimens. From ruminants, Escherichia coli (n = 77, 19.3%) predominated, followed by Staphylococcus aureus (n = 73, 18.3%). Antibiotic sensitivity testing (AST) revealed that E. coli resistance was highest for penicillin, streptomycin, and neomycin (77–93%). In addition, S. aureus was highly resistant to neomycin, followed by streptomycin and ampicillin (68–82%). More than 67% of E. coli isolates were multi-drug resistant (MDR) and only 2.6% were susceptible to all the tested antibiotics. Similarly, 65.6% of S. aureus isolates were MDR and only 5.5% were susceptible to all tested antibiotics. From non-ruminants, a total of 301 isolates were recovered. Escherichia coli (n = 108, 35.9%) and Staphylococcus spp. (n = 27, 9%) were the most frequent isolates obtained. For E. coli, the highest resistance was against amoxicillin, erythromycin, tetracycline, and neomycin (95–100%). Staphylococcus spp. had a high level of resistance to streptomycin, trimethoprim/sulfamethoxazole, tetracycline and gentamicin (80–100%). The MDR levels of E. coli and Staphylococcus spp. isolates from non-ruminants were 72.2 and 74.1%, respectively. Significantly higher resistance level were observed among isolates from non-ruminants compared to ruminants for tetracycline, amoxicillin, enrofloxacin, and trimethoprim/sulfamethoxazole.

Antimicrobial resistance in clinical isolates of Ureaplasma spp. from samples in Germany.

Ureaplasma urealyticum and U parvum are mollicutes species that colonize the urogenital tract of many asymptomatic persons but are also thought to be associated with symptomatic infections. Using 170 strains isolated between 2016 and 2019 in a German university hospital, resistance was tested by a combination of commercial tests, molecular methods and determination of minimal inhibitory concentrations. Rates of resistance to macrolides, tetracyclines and fluoroquinolones were 0%, 4.1% and 7.1%, respectively.

Potential public health impact of the development of antimicrobial resistance in clinical isolates of Pseudomonas aeruginosa on repeated exposure to biocides In vitro

Background: Antimicrobial resistance (AMR) is a real threat having the potential of impacting public health immensely. Biocides may contribute to AMR as they are routinely used in household formulations, often in suboptimal concentrations. Gram-negative bacteria like Pseudomonas aeruginosa (P. aeruginosa) can adapt to biocides such as chlorhexidine and cetrimide (CHX + CET) on repeated exposure and develop cross-resistance to antibiotics. Aim and Objective: The aim was to test CHX + CET laboratory-adapted clinical isolates of P. aeruginosa for the development of cross-resistance to antipseudomonal antibiotics. Materials and Methods: Ten clinical isolates of P. aeruginosa were included in the study. The initial antibiotic susceptibility pattern was noted before they were exposed to increasing concentrations of CHX + CET over several days. Briefly, 10 μl of bacterial suspension was inoculated into 10 ml of nutrient broth with the biocide and incubated at 37°C for 48 h. New series of tubes with increasing concentration of biocide were inoculated with growth from the previous tube every 48 h. Till, no further growth was obtained. Antibiotic susceptibility testing for antipseudomonal antibiotics by the disc diffusion as well as the minimum inhibitory concentration (MIC) by VITEK 2 bacterial identification system was performed and repeated before and after exposure to the biocide. The difference in the zone diameter and MIC was noted. Results: Significant difference (P < 0.05) in the mean of the zone size before and after exposure to CHX + CET was noted. Furthermore, there was an increase in MIC postexposure to the biocide. Conclusions: P. aeruginosa on exposure to biocides developed antibiotic resistance.

Changing pattern of antimicrobial resistance in clinical isolates from pyogenic infections in tertiary care hospital at Western Rajasthan, India

Background: Pyogenic wound infections are one of the most common clinical entities caused and aggravated by the invasion of pathogenic organisms. Despite the advancements in diagnostic techniques, treatment of pyogenic infections in the developing countries is challenging due to the emergence of multidrug-resistant (MDR) pathogens. This study was done to know the changing pattern of antimicrobial resistance in clinical isolates from pyogenic infections in patients attending a tertiary care hospital at Western Rajasthan, India. Methods and materials: This cross-sectional study was conducted at the Department of Microbiology in a tertiary care hospital during 2014–2015. Clinical specimens such as pus, wound aspirate, sterile body fluids except for CSF, wound swab, necrotic tissue, and surgical drainage were collected aseptically from suspected patients with pyogenic wound infections and processed. Bacterial isolates were identified by standard bacteriological methods and antibiotic susceptibility testing was done by Kirby-Bauer disc diffusion method as per CLSI guidelines. Results: Out of the total of 1190 clinical specimens processed, 231 (19.41%) specimens were from pyogenic infections; 108 (46.75%) specimens were culture positive. Gram-negative pathogens were 34%, followed by gram-positive pathogens which were 23%. Eleven percent were skin commensal flora. S. aureus (23%), E. coli (14%), Klebsiella spp. (7.4%), and Pseudomonas spp. (9.2%) were the common pathogens isolated. Staphylococcus aureus was resistant to Penicillin-G (100%), Erythromycin (56%) followed by Ciprofloxacin (28%). Among Enterobacteriaceae, Escherichia coli and Klebsiella spp. were resistant to Ampicillin (93.75%). and Amoxy-clave (93.75%) followed by ceftriaxone (81.25%). The majority of Pseudomonas isolates were susceptible to most of the antimicrobials. Conclusion: S.aureus and members of enterobacteriaceae are developing more resistance against commonly used antimicrobials, in comparison to Pseudomonas, which is commonly considered as a most resistant pathogen. This changing pattern is important in making the antibiotic policy.

Involvement of AcrAB and OqxAB Efflux Pumps in Antimicrobial Resistance of Clinical Isolates of Klebsiella pneumonia

Introduction: Infections caused by multidrug-resistant Klebsiella pneumonia characterize a major warning throughout the world owing to enhanced mortality and treatment limitations. Efflux pumps have an important role as a mechanism of antibiotic resistance in K. pneumoniae. In the current study, the role of AcrAB and OqxAB efflux pumps to antibiotic resistance was investigated in clinical isolates of K. pneumonia. Materials and Methods: During August 2017-October 2018, 110 clinical strains of K. pneumoniae were obtained from patients referred to the hospitals in Tehran. After microbiological/biochemical identification, and antimicrobial susceptibility test was performed using the disc diffusion method. Then, the minimum inhibitory concentration of ciprofloxacin-resistant K. pneumoniae strains was measured by the broth microdilution method. For investigating the efflux pump mediated drug resistance in K. pneumoniae, the presence, and prevalence of efflux genes (acrA/acrB and oqxA/oqxB) were examined by the Polymerase Chain Reaction (PCR) technique. Results: The results showed that resistance to ciprofloxacin, norfloxacin, gentamicin, kanamycin, cefotaxime, trimethoprim, chloramphenicol, and colistin was 19.09%, 21.81%, 10.0%, 9.09%, 44.54%, 25.45%, 11.81%, and 61.81%, respectively, in K. pneumoniae clinical isolates. The PCR technique demonstrated that the prevalence of acrA/acrB and oqxA/oqxB genes are 58 (52.72%) and 52 (47.27%), respectively. Conclusions: The results of this study reveal that the AcrAB and OqxAB efflux pumps have a major role in the antibiotic resistance of multidrug resistance K. pneumoniae isolates. Therefore, due to the easy transfer of antimicrobial resistance genes, the accurate detection of resistance genes by molecular methods is essential to control the spread of resistant strains.

Genomic Prediction of Antimicrobial Resistance: Ready or Not, Here It Comes!

Next-generation sequencing (NGS) technologies are being used to predict antimicrobial resistance. The field is evolving rapidly and transitioning out of the research setting into clinical use. Clinical laboratories are evaluating the accuracy and utility of genomic resistance prediction, including methods for NGS, downstream bioinformatic pipeline components, and the clinical settings in which this type of testing should be offered. We describe genomic sequencing as it pertains to predicting antimicrobial resistance in clinical isolates and samples. We elaborate on current methodologies and workflows to perform this testing and summarize the current state of genomic resistance prediction in clinical settings. To highlight this aspect, we include 3 medically relevant microorganism exemplars: Mycobacterium tuberculosis, Staphylococcus aureus, and Neisseria gonorrhoeae. Last, we discuss the future of genomic-based resistance detection in clinical microbiology laboratories. Antimicrobial resistance prediction by genomic approaches is in its infancy for routine patient care. Genomic approaches have already added value to the current diagnostic testing landscape in specific circumstances and will play an increasingly important role in diagnostic microbiology. Future advancements will shorten turnaround time, reduce costs, and improve our analysis and interpretation of clinically actionable results.