High Percentage Of Resistance Research Articles

1617. Mecillinam susceptibility against Enterobacterales isolated from urinary tract infections from US patients in 2018

BackgroundMecillinam is a unique amidinopenicillin antibiotic, being the first and the only compound in its class. In contrast to other beta-lactams, it has a unique mechanism of action whereby it exerts its antibacterial activity through binding to penicillin binding protein 2. Pivmecillinam is the oral-prodrug of mecillinam and recommended as a first line therapy in the IDSA guidelines for uncomplicated urinary tract infections (uUTI), despite not yet being available in the USA. To support the clinical development of mecillinam and pivmecillinam in the USA for the treatment of both complicated UTI and uUTI this study investigated the activity of mecillinam against Enterobacterales isolates from the USA during 2018.MethodsA total of 1,090 isolates from urinary tract infections from patients in the USA were tested. Activity of antibiotics was tested by CLSI methodology and susceptibility interpreted according to CLSI guidelines.ResultsSusceptibility and activity of each antibiotic are shown in the Table. Mecillinam MIC50 and MIC90 were 0.25 and 4 µg/mL, respectively and 94.5% of isolates were susceptible. Fosfomycin MIC50 and MIC90 were 2 and 32 µg/mL, respectively and 95.7% of isolates were susceptible. The other four comparator antibiotics showed MIC90 values >8 µg/mL and a 70.5 – 79.9% susceptible isolates. The highest MIC90 against all isolates combined was 64 µg/mL for nitrofurantoin and the highest percentage of resistance was obtained with trimethoprim-sulfamethoxazole with 29.5%. Resistance towards ceftriaxone and ciprofloxacin was 19.6% and 26.1%, respectively.Table ConclusionOverall, mecillinam showed the lowest MIC90 and a comparable susceptibility profile (94.5 % susceptible and 4.0 % resistant) to fosfomycin (i.e. 95.7% and 2.0% resistant) susceptible isolates). Resistance to ceftriaxone, ciprofloxacin and trimethoprim/sulfamethoxazole around or above 20% is concerning for their clinical usage to treat urinary tract infections. These encouraging susceptibility data warrant further studies to support the clinical development of mecillinam/pivmecillinam for the treatment of UTI in the USA.DisclosuresStephen Hawser, PhD, Tetraphase Pharmaceuticals (Scientific Research Study Investigator) Cedric Charrier, PhD, IHMA (Employee)Utility Therapeutics (Independent Contractor) Cyntia De Piano, PhD, IHMA (Employee)Utility Therapeutics (Independent Contractor) Morton Alexander, PhD, Utility Therapeutics (Employee, Shareholder) Anne Santerre Henriksen, MS, Maxel Consulting ApS (Employee)Utility Therapeutics (Independent Contractor)

Prevalence and characterization of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus isolated from bulk tank milk in Shandong dairy farms

Staphylococcus aureus (S. aureus) is one of the most common pathogens that cause mastitis in dairy cows. The emergence of methicillin-resistant S. aureus (MRSA) constitutes a serious public health concern due to its ability to colonize and infect humans and animals. In this study, the prevalence and antimicrobial resistance of S. aureus and MRSA were investigated from bulk tank milk (BTM) in Shandong dairy farms. A total of 418 pooled BTM samples from 418 different dairy farms were collected. The prevalence of S. aureus was 28.9% (121/418), while the MRSA prevalence was 0.7% (3/418). The strains exhibited high percentages of resistance to penicillin (74.4%) and erythromycin (58.7%), and 91.7% of the isolates were found to be resistant to at least one antimicrobial agent. Moreover, 55.4% (67/121) of isolates were multidrug-resistant (MDR). The most predominant virulence genes were sed (13.2%, 16/121) and sec (8.3%, 10/121), which encode Staphylococcal enterotoxins (sed and sec). Multilocus sequence typing (MLST) was employed to identify 18 different sequence types (STs). The predominant STs were ST50 (13.2%, 16/121) and ST398 (12.4%, 15/121), while ST97, ST2779, and ST3191 were observed in MRSA isolates. Staphylococcal protein A gene (spa) typing identified spa types t034 (12.4%, 15/121) and t189 (9.9%, 12/121) most frequently among S. aureus isolates, while t002, t267, and t437 were observed in MRSA isolates. The results of this study indicated that S. aureus isolates had a relatively high prevalence rate in BTM, and these isolates harbored multiple virulence and exhibited multiple antimicrobial resistance. Meanwhile, our results confirm the lurking threat of MRSA in raw milk and suggest the need for surveillance programs starting at the farm level.

Comparison of the Diagnostic Performance of qPCR, Sanger Sequencing, and Whole-Genome Sequencing in Determining Clarithromycin and Levofloxacin Resistance in Helicobacter pylori.

Helicobacter pylori antibiotic resistance is increasing worldwide, emphasizing the urgent need for more rapid resistance detection prior to the administration of H. pylori eradication regimens. Macrolides and fluoroquinolones are widely used to treat H. pylori. In this study, we aimed to compare the diagnostic performance of A) 23SrDNA qPCR (with melting curve analysis) and an in-house developed gyrA qPCR followed by Sanger sequencing with a commercial IVD-marked hybridization probe assay (for 23SrDNA and gyrA) using 142 gastric biopsies (skipping culturing) and B) the same two qPCR for 23SrDNA and gyrA (including Sanger sequencing) with whole-genome sequencing (WGS) and phenotypic characterization of clarithromycin and levofloxacin resistance using 76 cultured isolates. The sensitivity of both qPCRs was 100% compared to that of the commercial IVD-marked hybridization probe assay for the detection of H. pylori in gastric biopsies (without resistance testing). The specificity of the qPCR gyrA followed by Sanger sequencing was 100%, indicating that the best sequence identity was always H. pylori. The results show good agreement between molecular tests, especially between qPCR (inclusive Sanger sequencing) and WGS. Discrepancies (concerning mutated or wild type of positive H. pylori gastric biopsies) were observed between Sanger sequencing of the gyrA gene and the corresponding commercial hybridization probe assay, mostly because the high sequence diversity of the gyrA gene even at positions adjacent to the relevant codons of 87 and 91 interfered with obtaining correct results from the hybridization probe assay. Interestingly, we found several mixed sequences, indicating mixed populations in the gastric biopsies (direct detection without culturing). There was a high percentage of both levofloxacin and clarithromycin resistance in gastric biopsies (both between 22% and 29%, direct detection in gastric biopsies). Therefore, we recommend analyzing both targets in parallel. We confirmed that phenotypic resistance is highly correlated with the associated mutations. We concluded that the two qPCR followed by Sanger sequencing of the gyrA gene is a fast, cost-effective and comprehensive method for resistance testing of H. pylori directly in gastric biopsies.

Prevalence of antimicrobial resistance among gram-negative clinical isolates from a general hospital in Kuwait

Background: The impact of antimicrobial resistance on public health is a major issue worldwide. The objective of this study was to determine the antimicrobial resistance patterns of clinical gram-negative bacterial (GNB) isolates originated from different samples and locations at a general hospital in Kuwait. Methods and materials: A retrospective data of antimicrobial susceptibility testing of GNB from 2017–2018 were extracted from the microbiology laboratory at a general hospital in Kuwait. The data included the patient ID, location where the samples were collected (ICU, medical, pediatric, surgical, and out-patient clinics), specimen type, bacterial isolates (Acinetobacter spp., Enterobacter spp., E. coli, K. Pneumoniae, and P. aeruginosa), and the antimicrobial resistance profile. The susceptibility testing was performed using Vitek 2 and MicroScan systems. Results: Antimicrobial resistance profiles from a total of 6135 GNB isolates were obtained. In general, high resistance percentages (>50%) towards ampicillin, aztreonam, ciprofloxacin, trimethoprim/sulfamethoxazole, and cephalosporins drugs (ceftazidime, cefpodoxime, cefotaxime, and cefuroxime) was observed across the different bacterial species. However, low resistance (<10%) was generally observed against amikacin, amoxicillin/clavulanic acid, ertapenem, fosfomycin, nitrofurantoin, meropenem, piperacillin/tazobactam, and tigecycline. The proportion of antibiotic resistant bacteria by locations varied greatly by the microorganism isolated. For instance, E. coli isolates from medical and surgical wards had higher resistance prevalence compared to the other locations; whereas P. aeruginosa isolates from pediatric ward had higher resistance prevalence to antibiotics compared to other locations. The highest overall resistance (across all bacterial isolates) was detected in urine and wound samples. For instance, in urine samples, 22% and 26.3% of E. coli and K. Pneumoniae were resistant to amoxicillin/clavulanic acid. The prevalence of resistance to at least one antibiotic was high particularly among E. coli, K. Pneumoniae, and P. aeruginosa at 78.2%, 91.0%, and 73.6%, respectively. Moreover, the prevalence of multi-drug resistance among E. coli, K. Pneumoniae, and P. aeruginosa was 50.3%, 51.3%, and 48.7%, respectively. Conclusion: Monitoring the antibiotic susceptibility data of common bacterial organisms is vital to assess the status and trends of antibiotic resistance at hospital setting, to evaluate effective intervention strategies, and to select appropriate antibiotic treatment.

Extended spectrum β-lactamase producing Salmonella from broiler chickens, sewage and workers of broiler farms in Bangladesh

Background: Salmonella is known to be one of the most important pathogens causing gastroenteritis in human. Poultry act as a reservoir of this pathogen and it can be transmitted to the human through improper handling of poultry in poultry farm. The emergence of extended spectrum β-lactamase (ESBL) producing Salmonella in poultry poses high risk to human health especially in farm workers as well as environments. Therefore, a cross-sectional study was conducted to determine the prevalence of ESBL producing Salmonella in broiler chickens, farm sewage and farm workers and to investigate the presence of ESBL encoding genes. Methods and materials: One hundred and fifty samples comprising of cloacal swabs (n = 50) from broiler chickens, farm sewage water (n = 50) and hand wash water of farm workers (n = 50) were collected from 50 broiler farms of Mymensingh and Gazipur districts in Bangladesh. Salmonella was isolated using Xylose Lysine Deoxycholates (XLD) agar after pre-enriched into buffered peptone water. Salmonella was identified using five biochemical tests and confirmed by PCR. ESBL producing Salmonella were detected by double disk synergistic test and the presence of ESBL encoding genes were identified by multiplex PCR. Results: Salmonella was detected with an overall prevalence of 66%. Among the three types of samples collected, the highest prevalence, 82%, was observed for cloacal swabs. Hand wash water collected from farm workers exhibited the lowest Salmonella prevalence of 44%. Among the Salmonella isolates, 86.9% were found as ESBL producer comprising of 80.5% in broiler chickens, 88.9% in sewage water and 95.5% in hand wash water of farm workers. Within the ESBL encoding genes, blaTEM was the most predominant and found in all the isolates. Furthermore, blaCTXM-1 and blaCTXM-2 were found in one cloacal swab and one farm sewage water sample, respectively. But none of the isolates were found to be positive for blaSHV. Conclusion: High resistance percentage of ESBL Salmonella found in our study should be taken as a precautionary warning for the spread of it in broiler production industry and introduction into the poultry food chain. Further studies should be conducted to determine the source of AMR genes and how they are being transferred between different sources.

Occurrence and Antimicrobial Susceptibility Profiles of Multidrug-Resistant Aeromonads Isolated from Freshwater Ornamental Fish in Chiang Mai Province.

Antimicrobials are commonly used to prevent and treat disease in the ornamental fish industry. However, the indiscriminate and comprehensive overuse of unregulated antimicrobials without appropriate diagnostic examination could contribute to the development of antimicrobial-resistant strains of bacterial pathogens. Moreover, human infections caused by pathogens transmitted from fish or the aquatic environment are quite common. The frequent detection of antimicrobial resistance in ornamental fish and their environments are inevitable so as to decrease the transfer of antimicrobial-resistant bacteria from aquatic sources to other environments. This study evaluated the prevalence of common bacteria species and the antimicrobial susceptibility profile in ornamental fish that were sold in an ornamental fish shop in Chiang Mai, Thailand. Aeromonas spp. were the most dominant of the isolated species from the ornamental fish samples and accounted for 68.09% of the total. Other species detected included Vibrio spp., Pseudomonas spp., and Citrobacter spp. A high percentage of resistance to amoxicillin (93.75%), oxytetracycline (79.69%), and erythromycin (75.00%) was observed among the Aeromonas spp. The antimicrobial resistance information for ornamental fish is very limited, and the results from this study indicate that the Aeromonas spp. are highly resistant to several important antibiotics. The results suggest that additional steps should be taken to educate store owners to reduce the indiscriminate use of these antibiotics to decrease the antimicrobial resistance in ornamental fish to potentially improve public health.

Prevalence of Bacteria in Primary Schools

Pathogenic microorganisms are serious threats in schools, where contact with many microorganisms occur frequently throughout the school day. Classrooms are considered an optimal place for contact between microorganisms and young children. The aim of the current study was to study the prevalence of bacteria isolated in samples from different sites in primary schools and to show whether schools are sanitized and clean for children or it is just the core reason for their illness. The study was done in a highly standard private school and a public school in order to study the effect of variance in the social classes on the cleanliness of the schools. Different colonies were separated and identified by staining techniques and biochemical tests. Thirteen different types of bacteria with different amounts were isolated from 176 samples collected from different surfaces. It was found that the number of bacteria in public school is higher than that of the private school. The distribution of bacterial strains isolated from the two schools averaged 37.1% for Staphylococcus sp. followed by 11.3% for Enterobacter sp. and then 7.3%, 7.1% and 6.3% for Yersinia sp. Streptococcus sp. and Micrococcus sp. respectively. Other strains ranged between 5.9% to 1.5%. Bacterial isolates were tested for their susceptibility by well diffusion test against three commercial disinfectants commonly used for surface and hand cleaning in schools, namely; Clorox, Renol and Dettol. The highest percentage of resistance was seen against Renol (50%) followed by Dettol (38%) and was identified to be Escherichia coli, while least resistance occurring among all isolates was noticed against Clorox (18%). Children in private and public schools are at high risk of catching serious bacterial infections and they are surrounded by a cram of microorganisms. The current research shows that new ways must be developed to improve our schools’ hygiene to make it a healthier and safer place to learn in.

Antimicrobial Resistance Profiles of Escherichia coli from Diarrheic Weaned Piglets after the Ban on Antibiotic Growth Promoters in Feed.

This study aimed to survey the antimicrobial resistance profiles of 690 pathogenic Escherichia coli isolates obtained from Korean pigs with symptoms of enteric colibacillosis between 2007 and 2017, while assessing the change in antimicrobial resistance profiles before and after the ban on antibiotic growth promoters (AGPs). Following the Clinical and Laboratory Standards Institute guidelines, the antimicrobial resistance phenotype was analyzed through the disk diffusion method, and the genotype was analyzed by the polymerase chain reaction. After the ban on AGPs, resistance to gentamicin (from 68.8% to 39.0%), neomycin (from 84.9% to 57.8%), ciprofloxacin (from 49.5% to 39.6%), norfloxacin (from 46.8% to 37.3%), and amoxicillin/clavulanic acid (from 40.8% to 23.5%) decreased compared to before the ban. However, resistance to cephalothin (from 51.4% to 66.5%), cefepime (from 0.0% to 2.4%), and colistin (from 7.3% to 11.0%) had increased. We confirmed a high percentage of multidrug resistance before (95.0%) and after (96.6%) the ban on AGPs. The AmpC gene was the most prevalent from 2007 to 2017 (60.0%), followed by the blaTEM gene (55.5%). The blaTEM was prevalent before (2007–2011, 69.3%) and after (2012–2017, 49.2%) the ban on AGPs. These results provide data that can be used for the prevention and treatment of enteric colibacillosis.

Antibiotic Resistance Crisis in Urinary Tract Infections Utis in Egypt

Abstract Introduction/Objective Bacterial adaptation to antibiotics has been very successful. Over the past decade, the increase in antibiotic resistance has generated considerable medical problems. UTIs are one of the most common community-onset infections. The emergence of resistance to all classes of antibiotics in previously susceptible bacterial pathogens is a major challenge to infectious disease medicine. Thus, it is important that we forcefully implement strategies to reduce the rate of appearance and spread of resistant bacteria to allow new drug discovery to catch up with bacterial resistance development. Objectives: Methods The aim of this study is to predict the percentage of urine cultures antibiotic resistance in patients with UTIs in Egypt. Subjects and methods: A total of 200 subjects were enrolled in this study from The Delta region in Egypt; 38% males and 62% females with a median age of 39 years and 35 years respectively. Identification of the isolated organisms was identified by the cultural characters (Morphological characters of the purified bacterial isolates were carried out according to the colony characters, Gram stain reaction and biochemical tests for each organism using a standard semi-automated technique Results 98 cultures (49%) were observed to have resistance to 3- 5 classes of antibiotics including, 98% Cephalosporins, 85% β-lactam inhibitors and 71% fluoroquinolones; 66 females (57 gram -ve stain and 9 gram +ve stain) and 33 males (27gm -ve stain, 6gm +ve stain). 82 cultures (41%) were not resistant to any classes.; 32 males (28 gram -ve stain and 3 gram +ve stain) and 50 females (45 gram -ve stain and 5 gram +ve stain). 19 cultures (9.5%) were observed to be resistant to all antibiotics.; 12 males (11 gram -ve stain and 1 gram +ve stain) and 7 females (2 gram -ve stain and 5 gram +ve stain). Conclusion This study highlights the highest antibiotic resistance associated with urinary tract infection in Egypt as well as the classification of the organisms. The high resistance percentage is due to the overuse of antibiotics by public and inappropriate antibiotic prescribing. Antibiotics are unregulated and available over the counter without a prescription in Egypt which makes it easily accessible. We recommend regulating the use of antibiotics and lunch antimicrobial stewardship programs in Egypt.

Sobrevivência e perfil de resistência a antimicrobianos de isolados de Salmonella sp. em dejeto suíno armazenado

This study aimed determine the survival and antimicrobial resistance profile of Salmonella sp. samples isolated from swine manure systems plats with capacity for a minimum period of 120 days of wastewater. Of the 63-manure sample analyzed, Salmonella sp. was recovered only in nine (14.28%) of them, with serovars Typhimurium (79.4%), Panama (11.8%) and Derby (5.9%) and one isolate (2.9%) characterized as S. enterica. The presence at least one sample of Salmonella was determined in six systems, with the greatest number of isolations occurring at 120 days of storage. The antimicrobial resistance profile proved to be variable, and all samples were sensitive to amikacin, gentamicin, amoxicillin, neomycin and ciprofloxacin. Resistance to four or more antimicrobials was present in 20.6% of the isolates. There was a higher percentage of resistance after 120 days of storage in the systems and total multidrug resistance index (MAR) was 0.2. The role that waste treatment plays in the level of resistance of bacteria inhabiting the gastrointestinal tract is still controversial. While some studies point to a bneficial effect, represented by reduction of the resistance level of the samples during treatment, others affirm that the passage through the systems would provide the exchange of genes between bacterial strains resulting in an increase in multiresistance. This fact was observed in the present study, considering that the MAR index above o.2 is considered risk, since these microrganisms could act as reservoirs of resistance genes for other bacteria, including those in contact with the human population. Based on the results, it was concluded that samples of Salmonella survive after 120 days of storage of swine manure, with a tendency to increase in the resistance profile afther this period.

Detection of Antibiotic Resistance Genes in Some Multiple Antibiotic Resistant E. coli from Apparently Healthy Pregnant Women

The emerging drug resistance, especially among the Escherichia coli (E.coli) isolates from pregnant women, spread rapidly within the community. Urinary tract infection (UTI) is a well-known bacterial infection posing serious health problem in pregnant women. Also, multi-drug resistance is becoming rampant, and it is of serious public health concern. Treatment of E. coli is now a challenge due to continuous increase in resistance towards commonly prescribed antibiotics, thus posing a threat to treatment. Hence, the aim of the study is to determine antibiotic resistance genes in some multiple antibiotic resistant E.coli from apparently healthy pregnant women in Osun State. A cross-sectional study design was used to collect 150 mid-stream urine samples from apparently healthy pregnant women from March, 2018 to September, 2018. A well structured questionnaire and informed consent were used for data collection. Standard loop technique was used to place 0.001 ml of urine on Cysteine Lactose Electrolyte Deficient (CLED) medium, Blood agar, MacConkey agar and incubated at 37 °C for 24 h. A standard agar disc diffusion method was used to determine antimicrobial susceptibility pattern of the isolates. The molecular detection of the resistant genes was done using PCR techniques. The ages of women enrolled in this study ranges from 22 to 42 years (mean ± standard deviation = 31 ± 4.7 years). Escherichia coli showed high percentage of resistance to ampicillin and low resistance to ciprofloxacin and penicillin. All the E. coli isolates were sensitive to levofloxacin, and most were resistant to Meropenem. Multiple drug resistance was observed in all the isolates. Resistance genes in VIM 390bp, bla ctx-M 585bp and TEM 517bp were detected in some of the representative E. coli isolates profiled. This study identified the presence of Multi-drug resistance genes in E. coli associated UTI among pregnant women in Osogbo.

Propranolol, chlorpromazine and diclofenac restore susceptibility of extensively drug-resistant (XDR)-Acinetobacter baumannii to fluoroquinolones.

Nosocomial infections caused by extensively drug-resistant (XDR) or Pan-Drug resistant (PDR) Acinetobacter (A.) baumannii have recently increased dramatically creating a medical challenge as therapeutic options became very limited. The aim of our study was to investigate the antibiotic-resistance profiles and evaluate the various combinations of ciprofloxacin (CIP) or levofloxacin (LEV) with antimicrobial agents and non-antimicrobial agents to combat antimicrobial resistance of XDR A. baumannii. A total of 100 (6.25%) A. baumannii clinical isolates were recovered from 1600 clinical specimens collected from hospitalized patients of two major university hospitals in Upper Egypt. Antimicrobial susceptibility tests were carried out according to CLSI guidelines. Antimicrobial susceptibility testing of the respective isolates showed a high percentage of bacterial resistance to 19 antimicrobial agents ranging from 76 to99%. However, a lower percentage of resistance was observed for only colistin (5%) and doxycycline (57%). The isolates were categorized as PDR (2; 2%), XDR (68; 68%), and multi-drug resistant (MDR) (30; 30%). Genotypic analysis using ERIC-PCR on 2 PDR and 32 selected XDR isolates showed that they were not clonal. Combinations of CIP or LEV with antibiotics (including, ampicillin, ceftriaxone, amikacin, or doxycycline) were tested on these A. baumannii non-clonal isolates using standard protocols where fractional inhibitory concentrations (-FICs) were calculated. Results of the respective combinations showed synergism in 23.5%, 17.65%, 32.35%, 17.65% and 26.47%, 8.28%, 14.71%, 26.47%, of the tested isolates, respectively. CIP or LEV combinations with either chlorpromazine (CPZ) 200 μg/ml, propranolol (PR) in two concentrations, 0.5 mg/ml and 1.0 mg/ml or diclofenac (DIC) 4 mg/ml were carried out and the MIC decrease factor (MDF) of each isolate was calculated and results showed synergism in 44%, 50%, 100%, 100% and 94%, 85%, 100%, 100%, of the tested isolates, respectively. In conclusion, combinations of CIP or LEV with CPZ, PR, or DIC showed synergism in most of the selected PDR and XDR A. baumannii clinical isolates. However, these combinations have to be re-evaluated in vivo using appropriate animal models infected by XDR- or PDR- A. baumannii.

Virulence, resistance, and genetic diversity of Vibrio parahaemolyticus recovered from commonly consumed aquatic products in Shanghai, China

Vibrio parahaemolyticus can cause severe gastroenteritis, septicaemia and even death in humans. Continuous monitoring of V. parahaemolyticus contamination in aquatic products is imperative for ensuring food safety. In this study, we isolated and characterized 561 V. parahaemolyticus strains recovered from 23 species of commonly consumed shellfish, crustaceans, and fish collected in July and August of 2017 in Shanghai, China. The bacterium was not isolated from two fish species Carassius auratus and Parabramis pekinensis. The results revealed a very low occurrence of pathogenic V. parahaemolyticus carrying the toxin genes trh (0.2%) and tdh (0.0%). However, high percentages of resistance to the antimicrobial agents ampicillin (93.0%), rifampin (82.9%), streptomycin (75.4%) and kanamycin (50.1%) were found. A high incidence of tolerance to the heavy metals Hg2+ (74.7%) and Zn2+ (56.2%) was also observed in the isolates. ERIC-PCR-based fingerprinting of MDR isolates (77.5%) revealed 428 ERIC-genotypes, demonstrating remarkable genetic variation among the isolates. The results of this study support the urgent need for food safety risk assessment of aquatic products.

Antimicrobial resistance pattern of Acinetobacter; a multicenter study, comparing European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI); evaluation of susceptibility testing methods for polymyxin

Introduction: Acinetobacter species in clinical isolates cause severe infections including meningitis, bloodstream infection, ventilator-associated pneumonia, and surgical site infections. Objectives: In the present study, we evaluated Acinetobacter drug resistance using both European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI) antimicrobial susceptibility test methods. Materials and Methods: Clinical specimens of 128 patients who were admitted in three referral tertiary care teaching hospitals were enrolled in 2014. Blood and other sterile fluid samples, endotracheal secretion, ulcer, urine and other clinical specimen cultures were included, and microbial resistance of Acinetobacter isolates was determined and compared with disk diffusion and E-test antimicrobial susceptibility methods, using both the EUCAST and CLSI standards. Cohen’s kappa coefficient was also reported. Results: The highest percentage of resistance (96.9%) was found for meropenem and imipenem antimicrobials, and the lowest resistance (82.8%) was found for amikacin. The highest kappa agreement coefficient was for ciprofloxacin (kappa coefficient = 0.783), and the lowest kappa was for amikacin (kappa coefficient = 0.21). Conclusion: According to the results, it is better to consider amikacin as a choice in combination with another effective antimicrobial for treatment of drug resistant Acinetobacter.

Prevalence and antibiotic susceptibility pattern of uropathogens in outpatients at a tertiary care hospital.

Globally, urinary tract infection (UTI) is considered a major public health concern and the second most common bacterial infection affecting individuals of different ages. Bacteria are responsible for about 95% of UTIs. The emergence of antimicrobial resistance in uropathogens may lead to poor treatment outcomes in individuals with UTIs. The knowledge of the microorganism involves and antibiograms are important for the empirical treatment of UTIs. A cross-sectional study was carried out over 7 months (January to July 2019) with a focus on the identification of bacterial pathogens causing UTI and the evaluation of their antibiogram. In total, 804 urine samples were collected from individuals with suspected UTIs and inoculated on recommended media. Isolation and identification of the bacterial strains were performed using standard microbiological protocols. Antibiotic susceptibility was carried out following CLSI recommended guidelines. Among the tested specimens, 290 (36.1%) had significant bacterial growth and 147 (50.7%) of the strains were isolated from female patients. The frequently identified isolates were Escherichia coli (68.9%), followed by Klebsiella pneumoniae (8.9%) and Staphylococcus aureus (6.7%). The highest percentages of resistance have been observed against tested antibiotics. The majority of the isolates were extended-spectrum β-lactamase producers (85.2%) and multidrug-resistant (98.3%). We observed that Gram-negative bacteria were the main cause of UTIs where the predominant microorganism was E. coli.

The Relation between Class I Integrons and Multidrug-Resistance in Extended-Spectrum Beta Lactamase Producing Escherichia coli Isolates.

Background: The emergence and development of multidrug resistant (MDR) strains is due to inappropriate use of antibiotics and horizontal gene transfer between bacteria. The MDR strains of E. coli are highly associated with the presence of integrons; also, extended-spectrum beta lactamase producing isolates are usually resistant to various antibiotics. This study aimed to determine the incidence of class 1 integrons and its association with drug resistance in ESBL producing E. coli isolated from patients who were suffering from UTI. Methods: this study was conducted on 232 hospitalized patients with UTI, from which 160 E. coli strains were isolated. Antibiotic susceptibility testing and screening for ESBL production were performed by Kirby-Bauer disk diffusion method on Mueller- Hinton agar. Confirmation for ESBL production was performed by combined disc diffusion test. All MDR ESBL producing E. coli isolates were examined by conventional PCR for the presence of intI1 gene and related gene cassettes. Results: One hundred sixty E. coli strains (69 %) were isolated from 232 hospitalized patients. The highest percentage of resistance was to azetronam (92%) followed by ceftazidime and cefotaxime (90%) then ciprofloxacin (79 %). seventy two E. coli isolates (45%) were found to be ESBL producers and out of them, 61 isolates (84.7 %) were MDR. Out of the 61 MDR ESBL-producing isolates, class I integron was identified in 56 isolates (91.8%). Conclusion: our findings indicate high prevalence of class 1 integrons and gene cassettes suggests possible risk for the dissemination of resistance genes and the spread of MDR bacteria

Antibiotic Resistance and Virulence Gene Characteristics of Methicillin-ResistantStaphylococcus aureus(MRSA) Isolated from Healthy Edible Marine Fish

Thirty-three (33) isolates of methicillin-resistant Staphylococcus aureus (MRSA) from healthy edible marine fish harvested from two aquaculture settings and the Kariega estuary, South Africa, were characterised in this study. The phenotypic antimicrobial susceptibility profiles to 13 antibiotics were determined, and their antibiotic resistance determinants were assessed. A multiplex PCR was used to determine the epidemiological groups based on the type of SCCmec carriage followed by the detection of staphylococcal enterotoxin-encoding genes sea-sed and the Panton Valentine leucocidin gene (pvl). A high antibiotic resistance percentage (67–81%) was observed for Erythromycin, Ampicillin, Rifampicin, and Clindamycin, while maximum susceptibility to Chloramphenicol (100%), Imipenem (100%), and Ciprofloxacin (94%) was recorded. Nineteen (58%) of the MRSA strains had Vancomycin MICs of ≤2 μg/mL, 4 (12%) with MICs ranging from 4–8 μg/mL, and 10 (30%) with values ≥16 μg/mL. Overall, 27 (82%) isolates were multidrug-resistant (MDR) with Erythromycin-Ampicillin-Rifampicin-Clindamycin (E-AMP-RIP-CD) found to be the dominant antibiotic-resistance phenotype observed in 4 isolates. Resistance genes such as tetM, tetA, ermB, blaZ, and femA were detected in two or more resistant strains. A total of 19 (58%) MRSA strains possessed SCCmec types I, II, or III elements, characteristic of healthcare-associated MRSA (HA-MRSA), while 10 (30%) isolates displayed SCCmec type IVc, characteristic of community-associated MRSA (CA-MRSA). Six (18%) of the multidrug-resistant strains of MRSA were enterotoxigenic, harbouring the see, sea, or sec genes. A prevalence of 18% (6/33) was also recorded for the luk-PVL gene. The findings of this study showed that marine fish contained MDR-MRSA strains that harbour SCCmec types, characteristic of either HA-MRSA or CA-MRSA, but with a low prevalence of enterotoxin and pvl genes. Thus, there is a need for continuous monitoring and implementation of better control strategies within the food chain to minimise contamination of fish with MDR-MRSA and the ultimate spread of the bug.

Distribution and prevalence of antibiotic resistant bacteria in fish farms in East Malaysia

Aims: Aquaculture has grown tremendously in Malaysia over the past decades. However, guaranteeing aquaculture sustainability is a big challenge in terms of maintaining continuous output with a safe environment. Furthermore, the cultured species should be free from antibiotic resistance bacterial and antibiotic residue. This study aimed to monitor the existence and prevalence of antibiotic resistant bacteria associated with aquaculture farms in Sarawak. Methodology and results: Samples of water, sediment and fish were collected from five aquaculture farms within Sarawak. The samples were plated on trypticase soy agar and incubated at 28 °C for 24 h. A total of 204 bacterial isolates were isolated and analysed by (GTG)5-fingerprinting to determine genetic similarity among the bacterial isolates, so that representatives could be selected from similar clonal isolates. Based on the (GTG)5 profiles, 50 representative isolates were chosen for species identification using 16S rRNA sequencing. The identified bacteria were tested against 25 antibiotics using standard disk diffusion method. The 16S rRNA analysis revealed that the isolates constitute of 14 genera of bacteria including Bacillus (38%), Exiguobacterium (16%), Enterobacter (14%), Aeromonas (6%), Acinetobacter (4%), Citrobacter (4%), Staphylococcus (4%), Achromobacter (2%), Chitinophaga (2%), Fictibacillus (2%), Plesiomonas (2%), Pseudomonas (2%), Pseudoxanthomonas (2%) and Stenotrophomonas (2%). The antibiotic resistance analysis revealed that the highest percentage of resistance was recorded against streptomycin (75.0%), followed by ampicillin (66.0%), ceftriaxone (50.0%), rifampin (43.3%), aztreonam (36.8%) and ceftazidime (31.6%). Resistance to more than two antibiotics was observed in 40.0% of isolates with an overall multiple antibiotic resistant (MAR) index ranging from 0 to 0.79. Conclusion, significant and impact of study: The variability of antibiotic resistance patterns exhibited by different bacterial species suggests a dependence on selective pressures exhibited in different geographical locations. Our results show that the occurrence of MAR bacteria in an aquaculture environment with unknown history of antibiotics usage in the aquaculture system is possible, indicating a need to continuously monitor the presence of antibiotic resistant bacteria in the aquaculture system.

Identification and Antimicrobial Susceptibility of Granulicatella adiacens Isolated from Periodontal Pocket

Background: Periodontal diseases often occur in developing and developed countries, affecting 20 – 50% of the world population. Periodontitis may also complicate systemic health and have a risk to cause endocarditis infection. Granulicatella adiacens, part ofnutritionally variant streptococci (NVS), was proven to cause many diseases, especially endocarditis infection. GA was a part of commensal bacteria but also found to be causing periodontitis by co-aggregating with Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. The frequent used of antibiotics nowadays has led to increased resistance, and this concern led us to examine susceptibilities among several antibiotics. This study was conducted to prove which antibiotic can eliminate Granulicatella adiacens for its potential risk. Methods and Material: Bacteriasamples were isolated from 28 patients with periodontitis. The samples were delivered to the microbiology laboratory to be cultured and purified. After purification, the samples were identified using GP VITEK 2 Compact and tested using the antibiotic disc to find out the susceptibility rates. Results: From 28 samples, 20 samples were identified containing Granulicatella adiacens. Those samples were tested on seven types of antibiotic which is ofloxacin, ceftriaxone, azithromycin, vancomycin, tetracycline, levofloxacin, and clindamycin. Sensitive isolates were found on 90% of ofloxacin and levofloxacin group, 85% of azithromycin group, 50% of vancomycin group, and less than 50% for three other groups. High resistance percentages were found on cefriaxone (55%), vancomycin (45%), clindamycin (40%), tetracycline (30%), and less than 15% for three other groups. Conclusion: Ofloxacin and levofloxacin were found to be the most sensitive antibiotic tested, while ceftriaxone was the worst antibiotic in eliminating Granulicatella adiacens.

Frequency of antibiotic resistant enteropathogenic Escherichia coli (EPEC) in bovine carcasses at a slaughterhouse in Brazil

Escherichia coli (E. coli) comes in second place among microorganisms involved in outbreaks of foodborne diseases in Brazil and is among the 4 most prominent worldwide. Due to its importance, the purpose of this work is to verify microbiological quality by the presence of E. coli in bovine carcasses. A total of 365 E. coli were isolated by swabs of 154 carcasses of cattle, slaughtered in the municipality of Mineiros – GO, Brazil. The frequency of E. coli in the samples collected was 81% (125/154). Of these E. coli, 16 had the gene eae, and none presented the genes stx1 or stx2, so were therefore classified as EPEC. Thus, the frequency of EPEC in the carcasses was 9.7% (15/154). The strains were classified as part of the A or B1 groups. As for antimicrobial resistance, the antibiotics with the highest percentages of resistance were Cephalothin with 82% (41/50), followed by Gentamicin and Amikacin with 26% (13/50) each. None of the samples showed any production of the extended-spectrum beta-lactamase enzyme, but three EPECs were classified as multi-drug resistant. The results demonstrate the presence of multi-resistant EPEC in bovine carcasses slaughtered in Mineiros city, Brazil.