Extensive Drug Resistance Research Articles

Extensive drug-resistance in strains of Escherichia coli and Klebsiella pneumoniae isolated from paediatric urinary tract infections

ObjectivesUrinary tract infections (UTIs) in children are rapidly increasing worldwide and are commonly caused by extensively drug-resistant bacteria. This study determines the prevalence of UTIs in paediatric patients and evaluates the pattern of extensively drug-resistance in Escherichia coli and Klebsiellapneumoniae strains isolated from paediatric UTI patients. MethodsUropathogenic bacterial strains were isolated from paediatric patients with UTIs admitted to the Institute of Child Health, Lahore, Pakistan. Strains of both E. coli and K. pneumoniae were identified using biochemical characterisation and subjected to antibiotic susceptibility assays for 21 common antimicrobial drugs in order to determine their extensively drug-resistant profile. ResultsWe isolated 63 E. coli and 37 K. pneumoniae strains from 130 paediatric patients with UTIs over a period of six months. The antibiotic susceptibility assays showed that both the E. coli and K. pneumoniae strains exhibited a high degree of resistance against co-amoxiclav, cefuroxime, cefixime, cefotaxime, ceftazidime, ceftriaxone, ciprofloxacin, nalidixic acid, norfloxacin, pepedemic acid, and co-trimoxazole. However, several of the antimicrobial agents, including polymyxin B, colistin sulphate, chloramphenicol, nitrofurantoin, and fosfomycin, were found to retain their antimicrobial activities against both pathogens. The five highest antibiotic resistant strains were identified as E. coli strains ZK9, ZK40, and ZK60 and K. pneumoniae ZK32 and ZK89 using 16S rRNA gene sequencing. ConclusionOur study demonstrates that E. coli and K. pneumonia are the dominant extensively drug-resistant uropathogenic bacteria in community-acquired UTIs in our cohort. These uropathogens were found to be resistant to the majority of the routinely-used classes of β-lactams, pyridopyrimidines, quinolones, and fluoroquinolone antibiotics, and these findings may be useful for clinicians in their treatment of paediatric UTIs.

Prevalence, characteristics and antibiogram profile of Escherichia coli O157:H7 isolated from raw and fermented (nono) milk in Benin City, Nigeria

Background: Most Escherichia coli strains are harmless commensals, but some serotypes can cause serious food poisoning in their hosts, and are infrequently responsible for product recalls due to food contamination. The present study was carried out to determine the occurrence of E. coli O157:H7 and other E. coli strains from raw and fermented (nono) milk in Benin City, Nigeria.Methodology: A total of 66 (33 raw and 33 nono) milk samples were obtained from retailers from 3 different stations in Aduwawa market, Benin City, Nigeria between January and June, 2017. Samples were analysed by cultural methods for faecal coliforms using M-Fc agar, E. coli using Chromocult coliform agar, and E. coli O157:H7 using sorbitol MacConkey agar supplemented with cefixime and potassium tellurite. Presumptive E. coli andE. coli O157:H7 isolates were confirmed by polymerase chain reaction (PCR) assay using specific primers. Antimicrobial susceptibility profile of confirmed isolates was performed using the Kirby-Bauer disk diffusion method, with zones of inhibition interpreted according to the guidelines of Clinical and Laboratory Standards Institute (CLSI). Data were analysed using the SPSS version 21.0.Results: From the 66 nono and raw milk samples assessed in this study, all (100%) were phenotypically positive for E. coli O157:H7. A total of 19 E. coli O157:H7 and 41 other strains of E. coli were confirmed by PCR. The resistance profile of the 19 E. coli O157:H7 isolates showed 100% (19/19) resistance to penicillin G and ampicillin; 94.7% (18/19) to chloramphenicol; 89.5% (17/19) to erythromycin; and 78.9% (15/19) to sulfamethoxazole and oxytetracycline, while the sensitivity profile showed that 100% (19/19) E. coli O157:H7 isolates were sensitive to gentamicin and ofloxacin. The resistance profile of other 41 E. coli isolates showed 100% (41/41) resistance to penicillin G and ampicillin; 97.6% (40/41) to chloramphenicol; and 92.7% (38/41) to erythromycin, while 97.6% (40/41) were sensitive to gentamicin and kanamycin. Ten E. coli O157:H7 isolates (52.6%) showed extensive drug resistance pattern to 11 antibiotics in 7 antimicrobial classes with multiple antibiotic resistance (MAR) index of 0.46.Conclusion: Findings from the present study clearly indicated that the safety and quality of fresh and fermented milk were not satisfactory and could be of public health concern.
 Key words: Nono, Escherichia coli; Pathotypes, Resistance index, Public health, Milk

Evaluation of Colistin and Tigecycline Susceptibility Testing Methods for Klebsiella pneumoniae and Acinetobacter baumannii Clinical Isolates

Background: The evolution of nosocomial infections by multidrug resisitance (MDR) and extensive drug resistance (XDR) Acinetobacter baumannii and klebsiella pneumoniae are considered a major health problem owing to the relatively limited treatment options. Colistin and tigecycline are increasingly used as a last choice for treatment of these infections. The most accurate antibiotic susceptibility methods for colistin and tigecycline are still challenging. Objectives: The aim of the current study was to detect colistin and tigecycline antibiotic susceptibility of K. pneumoniae and A. baumanii and evaluate disk diffusion (DD), E- test and VITEK 2 automated system compared to broth dilution (BD) test. Methodology: This study was performed on 35 K. pneumoniae and 15 A. baumanii clinical isolates collected from patients admitted to Benha University Hospitals. The isolated strains were identified by the standard laboratory technique with subspecies identification by VITEK 2 automated system. Colistin and tigecycline antibiotic susceptibility for K. pneumoniae and A. baumanii were evaluated by E-test, disk diffusion and VITEK 2 compared to BD as the reference method. Results: Through the study of the studied k. pneumoniae and A. baumanii strains, The essential and categorical agreements of colistin suscebtibility were (82% & 80 %) for E-test, (92% & 98%) for VITEK 2 and categorical agreement for DD was 54%. The essential and categorical agreements of tigecycline suscebtibility were (96% & 98%) for E-test, (88% &78%) for VITEK 2 and categorical agreement for DD was 74%. Conclusion: For colistin, VITEK 2 is considered a reliable method to detect colistin susceptibility while E-test and disk diffusion showed a poor performance. For tigecycline, E-test showed the best performance compared to the gold standard test while shortcomings of automated VITEK 2 and manual DD were observed.

Molecular characteristics of drug-resistance Mycobacterium tuberculosis strains isolated from extra pulmonary tuberculosis sites

ObjectivesChina is the second high tuberculosis (TB) burden country in the world. This article was to determinate the molecular characteristic of drug resistance Mycobacterium tuberculosis (DRTB) strains from extra pulmonary tuberculosis (EPTB). MethodsThe medical records of patients with EPTB were reviewed and collected from 2006 to 2016. The drug sensitivity of all samples was studied. All multiple drug resistance (MDR) and extensive drug resistance (XDR) strains were included. The detection of the deletion of region of difference 105 (RD105) and mycobacterial interspersed repetitive-unit variable-number tandem-repeat (MIRU-VNTR) were used to discriminate the molecular type of EPTB strains. Results162 DRTB isolates were from patients with EPTB including 104 male and 58 female. Beijing genotype had a significant correlation with the patterns of DR (P<0.05), re-treatment patients (P<0.05) and gender (P<0.05). The history of treatment had a statistically significant correlation with patterns of DR (P<0.05) and gender (P<0.05). Patterns of DR had no correlation with gender (P>0.05). Of 162 strains Beijing family strains represented 91.4%. The cluster rate was 17.9% and clustering ratio was 11.1%. Beijing family genotype is predominant in the patients with EPTB. The cluster rate and clustering ratio was low. ConclusionsBeijing family genotype is predominant and highly epidemic in the patients with drug resistance extra pulmonary tuberculosis (DR-EPTB). The cluster rate and clustering ratio was low. Genotype of re-treatment male patient with DR-EPTB is more likely Beijing family genotype.

Emerging Trends of Resistance of Typhoid Fever in Paediatric Population: A Hospital Based Study

Objective: To evaluate the current trends of typhoid fever resistance in the local community.Methodology: This descriptive cross-sectional study, conducted at UMDC/ Creek General Hospital from February to August 2019. Patients of Korangi and Landhi included. A total of 68 patients included, diagnosed clinically and positive blood cultures. The data was analyzed on SPSS 20.0. Results: The average age of patients in this study was 5.16±3.449 years and weight of about 15.88±7.77 Kg. M:F ratio was approximately 1:1. Outpatient admissions were 49(72.1%) and emergency admissions were 19 (27.9%). The duration of symptoms was about 10.91±5.092 days. Out of these 68 patients, 57 (83.8%) had a history of medication for the same disease. The most common co-morbid was un-boiled water intake (66%), followed by malaria (12%). The most common clinical presentations were persistent fever (100%), anorexia (83.8%) and abdominal pain (80.9%). Blood culture and sensitivity showed that MDR/XDR is present in 60 (88.2%) patients. Sensitivity to first-line drugs was found in 1/10th of the study population while sensitivity to Meropenem and Azithromycin was approximately 90%. The complication occurred only in 2 patients (2.9%). Almost all patients recovered and there is no recurrence of symptoms in any of the patients following treatment with fever clearance time of 5.26±1.32 days only.Conclusion: This study revealed extensive drug resistance strains of Salmonella typhi in the studied population. This study reported increased use of unhealthy drinking water intake and prior medication which is one of the causes of this emerging resistance. Key words: Typhoid fever, Enteric Fever, Resistance, Multidrug resistance (MDR), Extensive drug resistance (XDR)

Efficacy of sub-MIC level of meropenem and ciprofloxacin against extensive drug-resistant (XDR) Pseudomonas aeruginosa isolates of diabetic foot ulcer patients.

The increasing emergence of extensive drug-resistant bacteria (XDR) among chronic diabetic foot ulcer patients (DFU) possess serious threat which leads to foot amputation. The ideal measurement estimations of the presently accessible medications are getting insufficient against extensive drug-resistant strains. For quite a long-time piperacillin monotherapy, Piperacillin-tazobactam, ceftazidime, Carbapenem class of anti-toxin, ceftalozane-Tazobactam, and so on, has been the suggested therapy towards persistent instances of diabetic foot ulcer but because of the resistance mechanism of the potent pathogens the potency and usage of the antibiotic concentration regime is under the radar. Based on this hypothesis two isolates namely VIT PC 7 &VIT PC 9 were found to be resistant to all five classes of antibiotics exhibiting extensive drug resistance (XDR). The whole-genome sequence of Pseudomonas aeruginosa VIT PC 7 and VIT PC 9 data showed the presence of various RND efflux related genes and antibiotic resistance genes. The broth microdilution assay showed minimum inhibitory concentration (MIC) for ciprofloxacin and meropenem, Synergistic test was performed through checkerboard analysis and sub-MIC concentration of ciprofloxacin/meropenem was deduced using ∑ FICI, Time kills analysis was done for varying time interval to check the maximum reduction in CFU/ml of the bacterial cells, sub-MIC level of meropenem and ciprofloxacin showed inhibitory activity at lower concentration respectively. In vitro time-kill analysis showed the decrease in the number of cells, suggesting that the synergistic antimicrobial combinations are effective in decreasing the MIC level, and combinational test involving sub-MIC level of antibiotics also showed maximum reduction in biofilm forming cells, portraying the effectiveness of both the drugs. Accordingly, an expansion in the antimicrobial spectrum can be accomplished by utilizing the ideal measurements of ciprofloxacin/meropenem in persistent condition like diabetic foot ulcer, sub-MIC level of ciprofloxacin/meropenem could be a promising choice for anticipation against the ongoing drug-resistant crisis.

Detection of Capsular Polysaccharide Virulence Genes rmpA and magA of Klebsiella Pneumonia Isolate from Diabetic Foot Ulcer Patient in Najaf Governorate in Iraq

Klebsiella Pneumoniae is an opportunistic pathogen, which mostly cause nosocomial infections. K.Pneumoniae utilizes a variety of virulence factors, especially capsule polysaccharide, lipopolysaccharide,fimbriae, outer membrane proteins and determinants for iron acquisition and nitrogen source utilization,for survival and immune evasion during infection. A total of (36) clinical swab specimens isolated frompatient with diabetic foot ulcer in Al-Sdder Medical City (Central Diabetic Foot) in Najaf Governorate,Iraq from November 2019 to February 2020 , for detection some virulence capsular polysaccharide genessuch as rmpA and magA that related with K1 serotype of K . pneumonia and associated with antibioticresistance pattern in patient of diabetic foot ulcer. Antibiotic susceptibility test of K. Pneumoniae isolatesagainst (20) of commonly used antibiotic showed there 25 (69%) of K. pneumonia isolate from diabeticfoot patient were Multi-drug resistance (MDR),while11(31%) were extensive-drug resistance (XDR). Theresults of amplified product demonstrated that K1 serotype of K . Pneumonia was positive in 23 (64%)of totally clinical specimen than other types of serotype ( Non-K1 serotype). (magA) gene that associatedwith hypermucoid viscosity was positive in 21 (58%) of total specimens while (rmpA) gene that regulate ofcapsular polysaccharide of K .pneumonia was positive in 22 (62%) of totally samples

Extensive drug resistance during low-level HIV viraemia while taking NNRTI-based ART supports lowering the viral load threshold for regimen switch in resource-limited settings: a pre-planned analysis from the SESOTHO trial.

WHO guidelines on ART define the HIV-1 viral load (VL) threshold for treatment failure at 1000 copies/mL. The Switch Either near Suppression Or THOusand (SESOTHO) trial, conducted in Lesotho from 2017 to 2020, found that patients with persistent viraemia below this threshold (100-999 copies/mL) benefit from switching to second-line ART. This pre-planned nested study assesses the prevalence of resistance-associated mutations (RAMs) in SESOTHO trial participants. The SESOTHO trial [registered at ClinicalTrials.gov (NCT03088241)] enrolled 80 persons taking NNRTI-based first-line ART with low-level HIV-1 viraemia (100-999 copies/mL) and randomized them (1:1) to switch to a PI-based second-line regimen (switch) or continue on first-line therapy (control). We sequenced relevant regions of the viral pol gene using plasma samples obtained at enrolment and 36 weeks. RAMs were classified with the Stanford HIV Drug Resistance Database. Sequencing data were obtained for 37/80 (46%) participants at baseline and 26/48 (54%) participants without viral suppression to <50 copies/mL at 36 weeks (21 control participants and 5 switch participants). At baseline, 31/37 (84%) participants harboured high-level resistance to at least two drugs of their current regimen. At 36 weeks, 17/21 (81%) control participants harboured resistance to at least two drugs of their current regimen, while no PI-associated resistance was detected in the 5 switch participants with ongoing viraemia. Among persons with low-level viraemia while taking NNRTI-based first-line ART enrolled in the SESOTHO trial, the majority harboured HIV-1 with RAMs that necessitate ART modification. These findings support lowering the VL threshold triggering a switch to second-line ART in future WHO guidelines.

Identification of drug resistance mutations among Mycobacterium bovis lineages in the Americas.

Identifying the Mycobacterium tuberculosis resistance mutation patterns is of the utmost importance to assure proper patient’s management and devising of control programs aimed to limit spread of disease. Zoonotic Mycobacterium bovis infection still represents a threat to human health, particularly in dairy production regions. Routinary, molecular characterization of M. bovis is performed primarily by spoligotyping and mycobacterial interspersed repetitive units (MIRU) while next generation sequencing (NGS) approaches are often performed by reference laboratories. However, spoligotyping and MIRU methodologies lack the resolution required for the fine characterization of tuberculosis isolates, particularly in outbreak settings. In conjunction with sophisticated bioinformatic algorithms, whole genome sequencing (WGS) analysis is becoming the method of choice for advanced genetic characterization of tuberculosis isolates. WGS provides valuable information on drug resistance and compensatory mutations that other technologies cannot assess. Here, we performed an analysis of the most frequently identified mutations associated with tuberculosis drug resistance and their genetic relationship among 2,074 Mycobacterium bovis WGS recovered primarily from non-human hosts. Full-length gene sequences harboring drug resistant associated mutations and their phylogenetic relationships were analyzed. The results showed that M. bovis isolates harbor mutations conferring resistance to both first- and second-line antibiotics. Mutations conferring resistance for isoniazid, fluoroquinolones, streptomycin, and aminoglycosides were identified among animal strains. Our findings highlight the importance of molecular surveillance to monitor the emergence of mutations associated with multi and extensive drug resistance in livestock and other non-human mammals.

Anti-mycobacterial Activity of 22 Iranian Endemic or Rare Plant Extracts Against Multi-drug and Extensively Drug-resistant Mycobacterium tuberculosis.

Due to side-effects and low efficacy of common drugs on new resistant strains of Mycobacterium tuberculosis (Mtb), investigation on novel drugs and natural compounds from rich sources of endemic plants is required. Thus, in the present study, the anti-mycobacterial effects of 22 Iranian endemic or rare plant extracts on multi-drug resistance (MDR) and extensively-drug resistance (XDR) Mtb isolates were evaluated. Twenty-two Iranian endemic and rare plant species from 9 families were collected and extracted by methanol. Their inhibitory-effects were then evaluated against Mtb H37Rv strain, seven clinical MDR-TB, and two XDR-TB isolates using the resazurin microtiter assay (REMA) method. The best of them were then fractionalized by five different polar solvents (Petroleum- Ether, Dichloromethane, Ethyl-Acetate, n-butanol, and water). To find anti-mycobacterial fractions, the inhibitory effect of isolated fractions was tested on Mtb H37Rv. Out of the 22 plants, 14 plant extracts demonstrated anti-mycobacterial activity with minimum inhibitory concentration (MIC) ranging from 4 to 30μg/mL against Mtb H37Rv. Eight plant extracts also exhibited anti-mycobacterial activity against MDR and XDR clinical strains of Mtb by MICs, i.e., 15-60μg/ml. Crinitaria grimmii and Linum album were the best antimycobacterial plants. Among fractions of Crinitaria grimmii, dichloromethane and n-butanol, and for Linum album, dichloromethane and Ethyl-Acetate fractions displayed more anti-mycobacterial effect as compared to crude extract on Mtb. The present study confirms the potential role of some plants to treat respiratory diseases as our results have demonstrated that these plants exhibit anti-mycobacterial activity in the acceptable range against Mtb. Thus, these plants could be good sources and alternatives of plant metabolites for anti-TB-drug development.

Emerging carbapenem-resistant Klebsiella pneumoniae sequence type 16 causing multiple outbreaks in a tertiary hospital in southern Vietnam.

The emergence of carbapenem resistance in Klebsiella pneumoniae represents a major global public health concern. Nosocomial outbreaks caused by multidrug-resistant K. pneumoniae are commonly reported to result in high morbidity and mortality due to limited treatment options. Between October 2019 and January 2020, two concurrent high-mortality nosocomial outbreaks occurred in a referral hospital in Ho Chi Minh City, Vietnam. We performed genome sequencing and phylogenetic analysis of eight K. pneumoniae isolates from infected patients and two environmental isolates for outbreak investigation. We identified two outbreaks caused by two distinct lineages of the international sequence type (ST) 16 clone, which displayed extensive drug resistance, including resistance to carbapenem and colistin. Carbapenem-resistant ST16 outbreak strains clustered tightly with previously described ST16 K. pneumoniae from other hospitals in Vietnam, suggesting local persistence and transmission of this particular clone in this setting. We found environmental isolates from a hospital bed and blood pressure cuff that were genetically linked to an outbreak case cluster, confirming the potential of high-touch surfaces as sources for nosocomial spread of K. pneumoniae . Further, we found colistin resistance caused by disruption of the mgrB gene by an ISL3-like element, and carbapenem resistance mediated by a transferable IncF/bla OXA-181 plasmid carrying the ISL3-like element. Our study highlights the importance of coordinated efforts between clinical and molecular microbiologists and infection control teams to rapidly identify, investigate and contain nosocomial outbreaks. Routine surveillance with advanced sequencing technology should be implemented to strengthen hospital infection control and prevention measures.

Treatment outcomes in new pulmonary tuberculosis cases depending on the main genotypes of &lt;i&gt;Mycobacterium tuberculosis&lt;/i&gt; in the Republic of Sakha (Yakutia)

The objective: to study treatment efficacy in new pulmonary tuberculosis patients depending on the genotypes of M. tuberculosis in the Republic of Sakha (Yakutia). Subjects and methods . The authors studied the clinical course and outcomes of 312 bacteriologically confirmed new pulmonary tuberculosis cases among patients admitted to hospital in 2010-2014. Molecular genetic tests included deletion analysis of RD105 and RD207 regions of DNA of the pathogen followed by MIRU-VNTR genotyping at 24 loci. Results. In the Republic of Sakha (Yakutia), the Bejing and S genotypes are of epidemic importance, these genotypes prevail among drug resistance mycobacteria. Tuberculosis caused by the Bejing genotype had multiple (MDR) and extensive drug resistance (XDR) in 30.6% of cases, its subtype CC2/W148 - in 85.3%. The S genotype was accompanied by MDR/XDR in 69.7% of cases, subtype S256 - in 78.9%. The treatment of patients was highly efficient according to the criteria of sputum conversion (92%) and cavities healing (89.4%). The lowest rates were observed in case of tuberculosis caused by the Bejing and S genotypes due to their subtypes CC2/W148 and S256. Clinical cure of new pulmonary tuberculosis caused by the Bejing genotype was achieved in 73.4% of cases, by subtype CC2/W148 - in 41.2% with a significantly higher proportion of treatment failures and lethal outcomes of tuberculosis than in other subtypes of this genotype. With the S genotype, the clinical cure was achieved in 72.7% of patients, with no significant difference in the incidence of unfavorable outcomes in patients with subtype S256.

Epidemiology of Biofilm Producing Acinetobacter baumannii Nosocomial Isolates from a Tertiary Care Hospital in Egypt: A Cross-Sectional Study.

ObjectiveThis cross-sectional study aims to determine the prevalence and associated risk factors of biofilm-producing A. baumannii nosocomial isolates from a tertiary care hospital, as well as to investigate any possible association of biofilm formation with the distribution of biofilm-related genotypes and antibiotic resistance phenotypes.MethodsA total of 94 non-duplicate A. baumannii nosocomial isolates were identified, their biofilm formation was quantitatively detected using the modified microtiter plate assay, and their susceptibilities to different antibiotics were determined using the breakpoint method. Isolates were then subjected to PCR assays targeting bap, ompA and blaPER-1 genes.ResultsThe majority (70.1%) of isolates were biofilm producers. The most prevalent biofilm gene was ompA (63.8%), followed by bap (13.8%) and blaPER-1 (10.6%). The presence of multi- and extensive-drug resistance (MDR and XDR) was significantly associated with biofilm producers (p = 0.017 and 0.002, respectively). The length of hospital stay (aOR= 0.023), the presence of ompA gene (aOR = 0.286) or bap gene (aOR = 0.346), ampicillin/sulbactam resistance (aOR = 1), and the presence of MDR (aOR = −0.329) or XDR (aOR = −0.252) were considered significant risk factors associated with biofilm-producing isolates.ConclusionThe high prevalence of biofilm-producing MDR and XDR nosocomial isolates in this study is worrisome and alarming. Characterization of risk factors could help control the continuous selection and transfer of this serious A. baumannii phenotype inside hospitals and improve the quality of patients’ care.

Unveiling the Potential Threat of Bacterial Oral Flora of Snake in Snake Bite Envenomation

Abstract Snakebite is an acute life-threatening and time-limited medical emergency. There is comparatively less evidence regarding the infections caused by pathogens present in the snake's oral flora that induce cellulites secondary to snake bite. Here, we report a case of 15-year-old male patient infected with Acinetobacter baumannii–induced sepsis who underwent hemodialysis posthemotoxic envenomation; inflicted by hemotoxic snake, Russell's viper (Daboia russelii) at right index finger, and he was treated with 20 vials of antisnake venom. He had acute kidney injury and underwent 10 cycles of hemodialysis. He had incidence of cellulites with sepsis, and pus culture showed the presence of A. baumannii isolates with extensive drug resistance. He was treated with piperacillin-tazobactam, vancomycin, imipenem, and colistin for the improvement of his health status. Thus, the management of snake bite–induced sepsis, bacterial susceptibility study of oral flora in local venomous snakes has to be studied.

A retrospective analysis of pathogen profile, antimicrobial resistance and mortality in neonatal hospital-acquired bloodstream infections from 2009-2018 at Tygerberg Hospital, South Africa.

Analysis of hospital-acquired bloodstream infection (HA-BSI) trends is important to monitor emerging antimicrobial resistance (AMR) threats and guide empiric antibiotic choices. A retrospective 10-year review of neonatal HA-BSI was performed at Tygerberg Hospital's neonatal unit in Cape Town, South Africa. Neonatal clinical and laboratory data from 2014 to 2018 (Period 2) was compared with published data from 2009 to 2013 (Period 1). The neonatal unit's HA-BSI rate declined between periods from 3.9/1000 inpatient-days in Period 1 to 3.3/1000 inpatient-days in Period 2 (p = 0.002). Pathogen yield and blood culture contamination rate were unchanged (11.0% to 10.4%, p = 0.233; 5.1% to 5.3%, p = 0.636 respectively). Gram-negative pathogens predominated (1047/1636; 64.0%); Klebsiella species, Staphylococcus aureus, Serratia marcescens, Enterococcus species and Acinetobacter baumannii were the most frequent pathogens. Extended spectrum beta-lactamase production was observed in 319/432 (73.8%) of Klebsiella species, methicillin resistance in 171/246 (69.5%) of Staphylococcus aureus and extensive drug resistance in 115/137 (83.9%) of Acinetobacter species (2009-2018). The crude mortality rate of neonatal HA-BSI episodes increased from Period 1 to Period 2 from 139/717 (19.4%) to 179/718 (24.9%) (p = 0.014), but HA-BSI attributable mortality remained unchanged (97/139 [69.8%] vs 118/179 [65.9%], p = 0.542). The in-vitro activity of piperacillin-tazobactam and amikacin declined during Period 2 (74.6% to 61.4%; p<0.001). Although HA-BSI rates declined in the neonatal unit, antimicrobial resistance rates in BSI pathogens remained high. Continuous BSI surveillance is a valuable tool to detect changes in pathogen and AMR profiles and inform empiric antibiotic recommendations for neonatal units in resource-limited settings.

Factors associated with time to sputum culture conversion of rifampicin-resistant tuberculosis patients in Klaipeda, Lithuania in 2016-2019: a cohort study.

The global proportion of successful treatment outcomes of Multidrug-Resistant/Rifampicin-Resistant Tuberculosis (MDR/RR-TB) remains unacceptably low. Time to culture conversion is important in making treatment-related decisions and is used as an interim predictor of pulmonary MDR/RR-TB treatment success. No previous studies have been conducted to assess determinants of time to culture conversion for MDR/RR-TB patients in Lithuania. Secondary analysis of data of culture-positive MDR/RR-TB patients, treated in Republican Klaipeda Hospital between 1st July 2016 and 1st July 2019 was performed. Culture conversion was defined as two consecutive negative cultures on solid media submitted at least 30 days apart. Factors associated with culture conversion were estimated by crude and multivariable Cox regression accounting for competing risks.In total, 115 consecutive patients starting treatment were included in the study. Of them, the majority was male (86/115; 74.8%) with a mean age of 48 (standard deviation (SD) ±12) years and Human Immunodeficiency Virus (HIV) negative (105/115; 91.3%). Nearly two-thirds (72/115; 62.6%) had XDR (extensive drug resistance) or MDR/RR-TB with additional resistance to second-line injectables or fluoroquinolones. Of 115 culture-positive patients at baseline, 103 (89.6%) patients achieved culture conversion during 12 months of treatment. The median time to culture conversion was 1.1 months (interquartile range: 0.9-1.8). Patients aged ≥60 years compared with <40 years [adjusted hazard ration (aHR): 0.40, 95% confidence interval (CI): 0.18-0.86], smokers (aHR: 0.39, 95% CI: 0.2-0.73), patients with positive sputum smear microscopy at baseline (aHR: 0.40, 95% CI: 0.25-0.63), cavities on initial chest X-ray (aHR: 0.56, 95% CI: 0.35-0.88) and resistance to at least one fluoroquinolone drug (aHR: 0.52, 95% CI: 0.32-0.84) were slower to culture convert. In conclusion, we recommend providing additional counseling, treatment adherence interventions and scale up the use of new and repurposed TB drugs to patient groups at risk of worse interim treatment outcome: patients aged 60 and above, with resistance to fluoroquinolones, smear-positive, smokers, or with signs of extensive disease evident on initial chest radiography.

Risk factors for nephrotoxicity associated with polymyxin B therapy in Chinese patients.

Background The widespread application of Polymyxin B, an active agent against multidrug resistance and extensive drug resistance Gram-negative bacteria, is majorly impeded by nephrotoxicity. Studies on the safety of polymyxin B in Chinese patients have not been widely reported. Objective This study aimed to explore the risk factors for polymyxin B-associated nephrotoxicity and guide its optimal place in therapy. Setting A tertiary care hospital located in eastern China. Methods This being a retrospective cohort study, we evaluated adult patients who received ≥ 72h of polymyxin B therapy from January 2018 to December 2019. However, patients who received polymyxin B therapy for less than 3 days or received renal replacement therapy at baseline were excluded. Pertinent information was retrieved from medical records. All statistical analysis was performed in SPSS version 22.0. Main outcome measure(s) The main outcome measures included the proportion of patients who developed nephrotoxicity when subjected to polymyxin B treatment and the independent risk factors for nephrotoxicity. Results A total of 119 patients received polymyxin and met the overall inclusion criterion. Of the 119, 46 patients (38.7%) developed nephrotoxicity. Through multiple logistic regression analysis, we found three variables as independent risk factors for nephrotoxicity, including co-morbidities of malignancy (OR 4.55; 95% CI 1.44-14.41; P = 0.010), co-infection with other microorganisms (OR 4.15; 95% CI 1.48-11.63; P = 0.007), and polymyxin B daily dose (OR 1.02; 95% CI 1.00-1.03; P = 0.026). Conclusion This retrospective cohort study identified three risk factors for polymyxin B-associated nephrotoxicity therapy in Chinese patients. These include malignancy, co-infection with other microorganisms, and polymyxin B daily dose.

Prevalence and Predictors of Antimicrobial Resistance Among Enterococcus spp. From Dogs Presented at a Veterinary Teaching Hospital, South Africa.

Background: While surveillance of antimicrobial drug resistance is ongoing in human medicine in South Africa, there is no such activity being performed in veterinary medicine. As a result, there is a need to investigate antimicrobial resistance among enterococci isolated from dogs in South Africa to improve understanding of the status of antimicrobial drug resistance given its public and veterinary public health importance. This study investigated antimicrobial resistance and factors associated with resistance profiles of enterococci isolated from dogs presented for veterinary care at a veterinary teaching hospital in South Africa.Methods: In total 102 Enterococcus isolated between 2007 and 2011 by a bacteriology laboratory at a teaching hospital were included in this study. Antimicrobial susceptibility of the isolates was determined against a panel of 18 antimicrobials using the Kirby Bauer disc diffusion technique. Univariate analysis was used to assess simple associations between year, season, breed group, age group, sex, and specimen as covariates and extensive drug resistance (XDR) as the outcome. Variables that were significant in the univariate analysis at a generous p-value ≤ 0.2 were included in the multivariable logistic models to investigate predictors of XDR.Results: All the Enterococcus isolates were resistant to at least one antimicrobial. High proportions of isolates were resistant against lincomycin (93%), kanamycin (87%), orbifloxacin (85%), and aminogycoside-lincosamide (77%). Ninety three percent (93%), 35.3, and 8.8% of the isolates exhibited multi-drug, extensive-drug and pan-drug resistance, respectively. Only year was significantly (p = 0.019) associated with extensive-drug resistance.Conclusion: Given the zoonotic potential of Enterococcus spp., the high antimicrobial resistance and multi-drug resistance observed in this study are a public health concern from one health perspective. The identified resistance to various antimicrobials may be useful in guiding clinicians especially in resource scarce settings where it is not always possible to perform AST when making treatment decisions.

Molecular analysis of blaSHV, blaTEM, and blaCTX-M in extended-spectrum β-lactamase producing Enterobacteriaceae recovered from fecal specimens of animals.

Colonization of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae as animal gut microbiota is a substantial global threat. This study aimed to determine the molecular characterization of blaSHV, blaTEM, and blaCTX-M variants in animals, as well as to evaluate the antimicrobial resistance conferred by these genes. We prospectively analyzed 1273 fecal specimens of farm and domestic animals for the isolation of enterobacteria that had the ESBL phenotype by using biochemical methods. The extracted genes were amplified by polymerase chain reaction and sequenced for the characterization of blaSHV, blaTEM, and blaCTX-M variants. The drug-resistance spectrum and hierarchical clusters were analyzed against 19 antibacterial agents. Out of 245 (19.2%) ESBL enterobacteria, 180 (75.5%) Escherichia coli and 34 (13.9%) Klebsiella pneumoniae were prevalent species. A total of 73.9% blaCTX-M, 26.1% blaTEM, and 14.2% blaSHV were found among the enterobacteria; however, their association with farm or domestic animals was not statistically significant. The distribution of bla gene variants showed the highest number of blaCTX-M-1 (133; 54.3%), followed by blaCTX-M-15 (28; 11.4%), blaTEM-52 (40; 16.3%), and blaSHV-12 (22; 9%). In addition, 84.5% of the enterobacteria had the integrons intI1. We observed ±100% enterobacteria resistant to cephalosporin, 7 (2.9%) to colistin (minimum inhibitory concentration breakpoint ≥4 μg/mL), 9 (3.7%) to piperacillin-tazobactam, 11 (4.5%) to imipenem, 14 (5.7%) to meropenem, and 18 (7.3%) to cefoperazone-sulbactam, without statistically significant association. Animal gut microbiota contain a considerable number of blaCTX-M, blaTEM, blaSHV, and integrons, which are a potential source of acquired extensive drug resistance in human strains and leaves fewer therapeutic substitutes.

Detection of blaCTX-M Genes among Extended Spectrum Beta Lactamase producing Pseudomonas aeruginosa isolated from Clinical Specimens in Erbil

Pseudomonas aeruginosa is one of the most common opportunistic pathogens that cause infections. The drug resistance in Pseudomonas aeruginosa may relate to the production of broad spectrum beta lactamase enzymes. This study aimed to detect multidrug resistant, extensively drug resistant and pan drug resistant isolates of Pseudomonas aeruginosa and to determine the frequency of extended spectrum beta lactamases enzymes by using a reliable test for detection blaCTX-M1, blaCTX-M2 and blaCTX-M3 genes in Pseudomonas aeruginosa. Pseudomonas aeruginosa isolated from different clinical samples, including sputum, wound, burn and urine. Identification and antibiotic susceptibility test were made by VITEK® 2 automated system. Identification confirmed by 16S ribosomal ribonucleic acid. The bacterial deoxyribonucleic acid was extracted and specific primers were used for detection blaCTX-M1, blaCTX-M2 and blaCTX-M3 genes. 62 Pseudomonas aeruginosa strains were obtained from 650 different clinical specimens (9.54 %). Of the 62 Pseudomonas aeruginosa isolates, the highest resistances were related to the antibiotics of ticarcillin, ticarcillin/clavulanic acid, piperacillin, piperacillin/tazobactam, ceftazidime and cefepime (100 %). However, the lowest resistance was observed to meropenem, imipenem (3.23 %), amikacin, ciprofloxacin (6.45 %) and gentamycin, tobramycin (19.35 %). Out of 62 bacterial isolates, 46 (74.19 %) were multidrugresistance strains, 2 (3.23 %) were extensive drug-resistance and no pan drug resistance was isolated. The gene frequency of blaCTX-M1 was 12 (19.35 %) and blaCTX-M2 5 (8.06 %), all specimens were negative for blaCTX-3 gene. This study highlights the increased prevalence of multidrug resistant Pseudomonas aeruginosa. The blaCTX-M genes provide Pseudomonas aeruginosa with an additional powerful resistance mechanism with potentially serious clinical implications, including limitation of the therapeutic options. The incidence of extended spectrum beta lactamases varies with geographic location and time.