Presence Of Mcr-1 Gene Research Articles

Molecular Detection of MCR-1 Gene Colistin Resistance in Klebsiella pneumoniae Isolated from Clinical Samples in Khartoum State Hospitals, Sudan 2021

Background: Antimicrobial Resistance is a major concern because a resistant infection may kill, and can spread to others, and imposes huge costs to individuals and society. The prevalence of MCR-1 resistance gene in Sudan possesses potential threat for treatment of patient especially when hospitalized. This study was implemented to determine the prevalence of MCR-1 Resistance gene in Khartoum state Hospitals in K. pneumoniae, isolates from clinical specimens using Polymerase Chain Reaction (PCR) technique. Methods: In this study, one hundred Klebsiella pneumoniae isolates from clinical specimens the study was (31%) were males, while (69 %) were females. There were aged from (17 to 40) years with (Mean = 27.4 and SD = 6.598). The isolated organisms were stored in 20% Glycerol Peptone Media. Samples were cultured and Re-identified using conventional methods. And tested to antimicrobial susceptibility test using Kirby baur disk diffusion Method. Results: 11% were Resistance for AST to colistin. then presence of MCR-1 gene was investigated by Polymerase Chain Reaction (PCR) technique. Out of 100 of Klebsiella pneumoniae Isolates, 4(4%) show positive MCR-1 Three of them from these 11% Resistance and only one from other 89 sensitive the data computerized and analyzed through SPSS 23. All statistical tests have done using chi-Square and the association of Colistin Resistance with MCR-1 gene were significant p-value (<0.05). The Colistin Resistance is an alarm from staff holders because it is considered as main treatment for ICU infections.

The first record of mcr-1 gene for colistin resistance in pigs from Serbia: should we be worried?

Colistin is being used as a last-resort drug to treat infections caused by multidrug-resistant (MDR) bacteria in humans. In veterinary medicine, colistin has been used for the treatment and prevention of infectious diseases. In the first study of mcr genes by multiplex PCR in healthy pigs from Serbia, we discovered mcr-1 in 4.85% out of 350 fecal samples. The presence of mcr-1 gene was detected on three farms located less than 100 km apart from each other, predominantly in piglet samples. The results point to the necessity of monitoring of colistin resistance and the mcr genes in food producing animals as well as restricting colistin usage on farms.

Molecular Detection of Colistin Resistance mcr-1 Gene in Multidrug-Resistant Escherichia coli Isolated from Chicken.

Zoonotic and antimicrobial-resistant Escherichia coli (hereafter, E. coli) is a global public health threat which can lead to detrimental effects on human health. Here, we aim to investigate the antimicrobial resistance and the presence of mcr-1 gene in E. coli isolated from chicken feces. Ninety-four E. coli isolates were obtained from samples collected from different locations in Bangladesh, and the isolates were identified using conventional microbiological tests. Phenotypic disk diffusion tests using 20 antimicrobial agents were performed according to CLSI-EUCAST guidelines, and minimum inhibitory concentrations (MICs) were determined for a subset of samples. E. coli isolates showed high resistance to colistin (88.30%), ciprofloxacin (77.66%), trimethoprim/sulfamethoxazole (76.60%), tigecycline (75.53%), and enrofloxacin (71.28%). Additionally, the pathotype eaeA gene was confirmed in ten randomly selected E. coli isolates using primer-specific polymerase chain reaction (PCR). The presence of mcr-1 gene was confirmed using PCR and sequencing analysis in six out of ten E. coli isolates. Furthermore, sequencing and phylogenetic analyses revealed a similarity between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, indicating that the six tested isolates were colistin resistant. Finally, the findings of the present study showed that E. coli isolated from chicken harbored mcr-1 gene, and multidrug and colistin resistance. These findings accentuate the need to implement strict measures to limit the imprudent use of antibiotics, particularly colistin, in agriculture and poultry farms.

Occurrence of Beta-Lactamases in Colistin-Resistant Enterobacterales Strains in Poland - a Pilot Study.

Sixty-five colistin-resistant Enterobacterales isolates recovered from different clinical specimens were analyzed. The strains were collected in 12 hospitals all over Poland within a period of nine months. Strains were analyzed for eight genes from the mcr family. The presence of mcr-1 gene was detected in three Escherichia coli strains. The 45/65 isolates were identified as ESBL producers. CTX-M-1-like enzymes were the most common ESBLs (n = 40). One E. coli and seven Klebsiella pneumoniae strains produced carbapenemases, with the NDM being produced by five isolates. Among all the strains tested, four and five were resistant to new drugs meropenem/vaborbactam and ceftazidime/avibactam, respectively.

Surveillance of plasmid-mediated mcr-1, mcr-3, mcr-4 and mcr-5 genes in human isolates, in Aveiro, Portugal

Background: Colistin belongs to polymyxins family, with broad-spectrum activity against Gram-negative bacteria, including most Enterobacteriaceae and it is considered last resource for Multidrug resistant (MDR) or Extensively drug-resistant phenotype therapy. The emergence of colistin resistance has caused great concern and resistance mediated by the plasmid-borne mcr genes has been detected worldwide. The aim of this study was to evaluate the presence of mcr-like genes in strains from patients attending the Centro Hospitalar do Baixo Vouga, E.P.E., Portugal. Methods and materials: All isolates included in this study were non-duplicate and identified with the automated method VITEK2® (BioMèrieux, France), antimicrobial susceptibility testing was performed, and the advanced expert system suggestions were taken in consideration. Strains identified as colistin-resistant were confirmed by MICRONAUT-S broth microdilution Colistin MIC test (Merlin Diagnostika). The NG-Test MCR-1 (NG, Biotech, France), was used to detect the presence of the MCR-1 enzyme. Polymerase chain reaction technique was used to screen the presence of the colistin resistance plasmid-mediated mcr-1, mcr-3, mcr-4 and mcr-5 genes using primers described previously. The presence of IncX4 replicon was inspected in all mcr-like-carrying strains. Results: During the timeframe of this study (2017–2019) a total of 6189 strains were isolated, among them 13 exhibited non-intrinsic resistance to colistin (six Klebsiella pneumoniae, four Escherichia coli, two Enterobacter cloacae and one Pseudomonas aeruginosa). Seven strains were recovered from inpatients and six from outpatient samples. Patients age range from 56 to 89 years-old. mcr-1 gene was detected in two strains from patients from orthopedics ward - Escherichia coli (Ec536586) and Klebsiella pneumoniae (Kp574799). IncX4 plasmid was not detected in strains. Conclusion: Resistance in most of the strains included in this study could not be explained by the presence of mcr-1 gene. One can hypothesize that it may be due to chromosomal mutations that have already been described in Enterobacteriaceae and also in P. aeruginosa. Further studies will be undertaken to screen for the presence of other acquired genes. Since the prevalence rate of carbapenem-resistant Enterobacteriaceae has been increasing in our region, we highlight the importance of a Surveillance Program to monitor the spread of the plasmid-mediated colistin resistance genes into MDR Gram-negative bacteria.

Research note: Occurrence of mcr-encoded colistin resistance in Escherichia coli from pigs and pig farm workers in Vietnam.

WHO considers colistin as a highest priority critically important drug for human health, and occurrence of colistin-resistant bacteria in livestock is of health concern. The current study determined occurrence of colistin-resistant Escherichia coli in pigs and workers at pig farms in Vietnam, and investigated the genetic background for resistance. Colistin-resistant E. coli were detected from pigs in 53/116 (45.7%) farms, and from workers taking care of the pigs in 21/94 (22.3%) farms. Colistin-resistant isolates showed MIC to colistin between 4-16mg/L, they were multidrug resistant (99%) and resistance was caused by the presence of mcr-1 genes in 97/102 (95.1%) E. coli from pigs and in 31/34 (91.1%) isolates from humans. mcr-1 is considered a plasmid-encoded gene, but this was not confirmed in the current investigation. In total, one pig isolate carried both mcr-1 and mcr-3 genes, whereas mcr-2, mcr-4 and mcr-5 genes were not detected. Shared resistance profiles between pig and human isolates on the same farm was only observed in four farms. The study showed that commensal E. coli from pigs in Vietnam constitute a reservoir for colistin-resitant E. coli, however, further studies are needed to confirm that mcr genes are associated with plasmids and their importance for human health.

Colistin susceptibility among multidrug resistant Gram-negative bacilli isolated from Tertiary hospital in Egypt

Colistin is considered as the last resort for treatment of bacterial infections caused by carbapenem-resistant Gram-negative bacilli (GNB). Colistin resistance can increase due to the spread of plasmid-borne mcr-1 gene. This study aimed to determine colistin susceptibility and to detect the presence of mcr-1 gene in the clinical isolates of GNB recovered from different clinical samples collected from Ain Shams University Hospital, Cairo, Egypt. About thirty-five GNB isolates were recovered from the different clinical samples that were collected during the period from February-April, 2019. These isolates were subjected to antibiotic susceptibility testing using disc diffusion assay, and Colistin susceptibility through the E-test. In addition, conventional Polymerase chain reaction (PCR) was carried out for detection of mcr-1 gene among the colistin GNB resistant isolates. Most of the GNB isolates (60 %) were recovered from blood samples. Klebsiella pneumoniae (K. pneumoniae) was the most common isolated bacterium; that was represented by 24 isolates (68%). Out of the 35 GNB, only five isolates (14.3 %) were resistant to colistin by E-test, with MIC >256 𝜇g/ ml. The mcr-1 gene was detected only in one Pseudomonas aeruginosa (P. aeruginosa) isolate. This study concluded the low frequency of mcr-1 gene among the current GNB isolates. However, a large scale study is recommended to detect colistin resistance among GNB.

Detection of colistin resistant Gram negative bacilli in intensive care unit patients admitted to Ain Shams University Hospitals.

Background: Colistin is the last choice for serious infections caused by multidrug-resistant Gram negative bacteria and one of the prominent causes for spreading the resistance is Plasmid-borne Mobile Colistin Resistance (mcr). Broth microdilution method (BMD) is the reference tool for Colistin MIC determination, but it has many obstacles, so commercial BMD methods had been developed that are more user-friendly than the reference method and (Liofilchem ® ComASPTM) is one of them, which we used to determine Colistin MIC in this study. Objective: to detect Colistin resistant gram negative bacilli by ComASPTM Colistin (formerly Sensi Test™Colistin) among Intensive Care Unit (ICU) patients admitted to Ain Shams university hospitals and to Screen the presence of mcr-1 gene by Polymerase Chain Reaction (PCR) in Colistin resistant isolates. Methodology: This Observational cross-sectional study was performed in the Medical Microbiology and Immunology Department, Faculty of Medicine, Ain Shams University between June 2019 to November 2019. One hundred isolates of Gram negative bacilli were obtained from patients admitted at different Intensive Care units of Ain Shams University Hospitals. Full identification was done by conventional microbiological methods, Then MIC was measured for all isolated organisms by using commercial BMD ComASPTM colistin, PCR was done for Colistin resistant isolates to detect mcr-1 gene. Results: 60% of the Gram negative bacilli (GNB) isolates were K.pneumoniea.Colistin resistance was 14% among 100 (GNB), 35.7% of these Colistin resistant were K.pneumoniea obtained from urine samples. Prevalence of mcr-1 gene was 7.1%. Conclusion: Commercial BMD ComASPTM Colistin is simple and uncomplicated method for detection Colistin susceptibility.

Investigation of colistin resistance gene mcr in gut bacteria from patients with acute diarrheal

Objective: To investigate the presence of colistin resistance gene mcr in gut bacteria from patients with acute diarrhea. Methods: Fresh stool samples were collected from 150 outpatients with acute diarrhea in the intestinal clinic of Henan Provincial People's Hospital, and were directly detected for the presence of mcr by PCR after enrichment in the broth.The mcr-producing bacteria were further isolated and identified by MALDI-TOF MS (Bruker Biotyper). Antimicrobial susceptibility of these isolates was conducted by micro-broth dilution method.The presence of other antimicrobial genes were investigated by PCR and sequencing. Results: Among the 150 cases of acute diarrhea, 4 patients(2.7%) were positive for mcr-1 gene, and only 1(0.7%) contained both mcr-1 and mcr-3.Four isolates of Escherichia coli and one isolate of Aeromonas veronii were obtained from the mcr positive cases.The presence of mcr-1 gene was found in all of the E. coli isolates, and the mcr-3 gene was identified in A. veronii. Conclusions: Our study demonstrated the relatively low prevalence of colistin resistant gene in the faeces of acute diarrhea outpatients, and mcr-1 is the dominant colistin resistant gene.The presence of mcr-3 gene was also found in the clinical sample, and it indicats the coexistence of mcr-1 and mcr-3 in the intestinal tract of diarrhea patient.We should pay attention to the potential transmission of these resistance genes and further investigations are urgently needed.

High Prevalence of Colistin Resistance and mcr-1 Gene in Escherichia coli Isolated from Food Animals in China.

The objective of this study was to determine the minimal inhibitory concentration of colistin for Escherichia coli from food animals and the possible underlying colistin resistance mechanisms. During 2007–2014, 4,438 E. coli isolates of food animal origins were collected. The susceptibility of colistin was tested by the agar dilution method. Mutations in pmrA, pmrB, and mgrB and the presence of mcr-1 gene were determined by PCR and DNA sequencing. Complementation experiments were carried out to evaluate the contribution of the mutations to colistin resistance. There was a high frequency of colistin resistance in E. coli from pigs on farm (24.1%) and at slaughter (24.3%) in 2013–2014, followed by chickens on farm (14.0%) and at slaughter (9.5%). The resistance frequency of E. coli in cow isolates was the lowest (0.9%). MIC distribution for colistin showed that most isolates (75.2%) were distributed at 0.25 mg/L–0.5 mg/L, followed by 4 mg/L–8 mg/L (16.8%). Compared with the isolates from pigs and chickens recovered during 2013–2014, E. coli isolates collected during 2007–2008 (5.5%) and 2010–2011 (12.4%) showed significantly lower frequency of colistin resistance (P < 0.05). DNA sequencing and complementation experiments failed to detect any insertion inactivation or mutation in pmrA, pmrB, and mgrB associated with colistin resistance. However, 91.0% colistin-resistant isolates were positive for mcr-1. The high frequency of colistin resistance and mcr-1 gene among E. coli isolates from food animals in China urged the need to minimize potential risks of colistin resistance development and the spread of mcr-1 gene.