scholarly journals Upstream region of OprD mutations in imipenem-resistant and imipenem-sensitive Pseudomonas isolates

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masoumeh Kiani ◽  
Akram Astani ◽  
Gilda Eslami ◽  
Mansoor Khaledi ◽  
Hamed Afkhami ◽  
...  

AbstractThe current study was aimed at investigating the prevalence of the mutations upstream of the oprD coding region and its promoters among imipenem-resistant and sensitive Pseudomonas aeruginosa isolated from educational hospitals in Yazd City, Iran. All isolates were identified by the conventional biochemical tests. Then, the antibiotic resistance of these isolates was determined using the disk diffusion method according to the CLSI guidelines. Also, the E.test was performed to determine the minimum inhibitory concentrations (MIC) of imipenem. The mutations of this gene were recognized by the amplification of this region and subsequently sequenced. Sequencing of the genomic region upstream of oprD these regions were done in the 29 clinical strains. Statistical analysis was done by the statistical software SPSS-18. Seventy (77.7%) of isolates had MIC ≥ 16 and were resistant to imipenem. Mutations of the upstream of the oprD gene and its promoters were seen in 25 (86.2%) isolates and 4 isolates had no mutation. One isolate had a base substitution A→Cat nt 25 in the coding region and this isolate had a point mutation leading to an amino acid change at positions 9 (I→L). Our study results indicated that none of the strains had mutation in Shine-Dalgarno and the point mutations were the most common mutations upstream of the oprD coding region among P. aeruginosa isolates. Mutations were observed in imipenem-resistant isolates and it seems this mechanism is effective in resistance of isolates to imipenem and this confirmed that the indiscriminate use of antibiotic should be controlled.

2021 ◽  
Author(s):  
Masoumeh Kiani ◽  
Akram Astani ◽  
Nahid Rezaei Khozani ◽  
Mansoor Khaledi ◽  
Hamed Afkhami ◽  
...  

Abstract The current study was aimed at investigating the prevalence of the mutations upstream of the oprD coding region and its promoters among imipenem-resistant and sensitive Pseudomonas aeruginosa isolated from educational hospitals in Yazd City, Iran. All isolates were identified by the conventional biochemical tests. Then, the antibiotic resistance of these isolates was determined using the disk diffusion method according to the CLSI guidelines. Also, the E.test was performed to determine the minimum inhibitory concentrations (MIC) of imipenem. The mutations of this gene were recognized by the amplification of this region and subsequently sequenced. Sequencing of the genomic region upstream of oprD these regions were done in the 29 clinical strains. Statistical analysis was done by the statistical software SPSS-18. Seventy (77.7%) of isolates had MIC ≥ 16 and were resistant to imipenem. Mutations of the upstream of the oprD gene and its promoters were seen in 25 (86.2%) isolates and 4 isolates had no mutation. One isolate had a base substitution A→Cat nt 25 in the coding region and this isolate had a point mutation leading to an amino acid change at positions 9 (I→L). Our study results indicated that none of the strains had mutation in Shine-Dalgarno and the point mutations were the most common mutations upstream of the oprD coding region among P. aeruginosa isolates. Mutations were observed in imipenem-resistant isolates and it seems this mechanism is effective in resistance of isolates to imipenem and this confirmed that the indiscriminate use of antibiotic should be controlled.


2020 ◽  
Author(s):  
Masoumeh Kiani ◽  
Akram Astani ◽  
Hamed Afkhami ◽  
Mansoor Khaledi ◽  
Javad Fathi ◽  
...  

Abstract Background: The current study was aimed to investigate the prevalence of the mutations of the oprD gene among imipenem-resistant and -sensitive Pseudomonas aeruginosa isolated from educational hospitals in Yazd, Iran.Methods: In this study, 90 P. aeruginosa isolates were collected from different clinical samples and transferred to the Department of Microbiology, Shahid Sadoghi University of Medical Science, during 2015 to 2016. All isolates were identified by the conventional biochemical tests and antibiotic resistance was determined using disk diffusion method. E. test was performed to determine the minimum inhibitory concentrations (MIC) of imipenem. The mutations of upstream of the oprD coding region and its promoters and 54 primary nucleotide of this gene were recognized by the amplification of this region and subsequently sequenced.Results: Seventy (77.7%) of isolates had MIC≥16 and were resistant to imipenem. The results showed that the rate of resistance to imipenem is increasing. Mutations of the upstream of the oprD gene and its promoters were seen in 25 (86.2%) of isolates and 4 strains had no mutation. All of the imipenem-resistant isolates had mutations. One isolate had a base substitution A→ C at nt 25 in coding region and this isolate had a point mutation leading to an amino acid change at positions 9 (I→L). Conclusion: The results showed that imipenem resistance is increasing in P. aeruginosa, also indicated that the point mutations were the most common cause of the inactivation of upstream of the oprD coding region among P. aeruginosa isolates, it seems this mechanism is effective in resistance of isolates to imipenem.


2020 ◽  
Vol 10 (1) ◽  
pp. 1-4
Author(s):  
Omor Ahmed Chowdhury ◽  
Md Raihan Ahmed ◽  
Md Raihan Dipu ◽  
Md Aftab Uddin

The use of earphones has increased in recent times throughout the world especially among the different level of students such as school, college or university who have a higher tendency of sharing these among them. Unlike airline headsets, headphones and stethoscope ear-pieces, ear phones are often shared by multiple users and can be a potential medium for transmission of pathogens, which can give rise to various ear related infections. The objective of this study was to detect the pathogenic bacteria from the ear-phones used by the students of Stamford University Bangladesh. A total of 16 ear-phone swabs were collected by sterile cotton swabs. The swabs were inoculated onto blood agar and incubated aerobically overnight at 37oC. Microscopic observation and standard biochemical tests were performed to confirm the identification of all the bacterial isolates. Six presumptively identified Staphylococcus spp. (38%) were tested against six different types of antibiotics following Kirby-Bauer disk diffusion method. Isolates were found to be 84% resistant against Cotrimoxazole and demonstrated 100% sensitivity to Vancomycin and Ciprorofloxacin. The findings of this study suggest the users to disinfect their respective ear phones and not to exchange them as they may act as a potential source to transfer pathogenic and antibiotic resistant bacteria among the ear phone users. Stamford Journal of Microbiology, Vol.10 (1) 2020: 1-4


2021 ◽  
Vol 36 (1) ◽  
pp. 1-14
Author(s):  
A.Z. Nhidza ◽  
C. Gufe ◽  
J. Marumure ◽  
Z. Makuvara ◽  
T. Chisango ◽  
...  

The presence of Salmonella in food products and emergence of antibiotic resistance are the major challenges facing public health policies. A total of 2749 crocodile meat samples obtained from the Central Veterinary Laboratories in Zimbabwe were screened for Salmonella specieswere collected from three Zimbabwean commercial farms between the year 2012 and 2019 for a retrospective observational study to determine the prevalence and magnitude of antibiotics resistant Salmonella species in crocodile meat. The isolation of Salmonella was in accordance with the ISO 6579:2002 and the antibiotic susceptibility testing was carried out based on Clinical and Laboratory Standard Institute’s recommendations by means of the Kirby-Bauer disk diffusion method. SILAB Database was used to determine the prevalence of Salmonella species. Prevalence was stratified by year and farms. Twenty Salmonella isolates were identified using biochemical tests, and 15 were confirmed by polymerase chain reaction (PCR). Antimicrobial susceptibility profiles of the confirmed Salmonella isolates were examined using 14 antibiotics. The overall prevalence of Salmonella species in crocodile meat samples was 0.5%. The prevalence of Salmonella species ranged from 0.04% to 0.44% in the crocodile meat samples and annual prevalence ranged from 0.01% to 1%. The highest prevalence of Salmonella (4.4%) was recorded in the year 2012. Salmonella isolates from one of the three tested farms were resistant to Erythromycin (73.33%), Ampicillin (80%), and Penicillin G (100%). Generally, Salmonella isolates displayed lower resistance to Cefepime, Ceftriaxone, Amikacin, Tetracycline, Ertapenem, Florfenicol, and Erythromycin (0-53.33%) whereas all Salmonella isolates showed susceptibility to Cefepime, Ceftriaxone, Ertapenem, and Florfenicol. Although the study indicates low prevalence of Salmonella species in crocodile meat, there is a need for strict implementation of Hazard Analysis Critical Control Point (HACCP) to reduce contamination rates in meat and its products


2008 ◽  
Vol 52 (No. 4) ◽  
pp. 169-174
Author(s):  
M. Holasova ◽  
R. Karpiskova ◽  
S. Karpiskova ◽  
V. Babak ◽  
J. Schlegelova

With a microdilution method, using the commercial diagnostic test Sensititre Susceptibility Plates for Campylobacter MIC (Trek Diagnostic Systems, Cleveland, OH, USA), disk diffusion and agar dilution method, resistance to six antimicrobial agents were examined in a reference strain <i>Campylobacter jejuni</i> ATCC 33560 and 73 thermo-tolerant isolates of <i>Campylobacter</i> spp. For the microdilution method and all tested antimicrobial agents, our determined values of microbiological breakpoints of resistant strains were suggested as the minimum inhibitory concentration (MIC<sub>R</sub>) for ciprofloxacin &ge; 0.5, erythromycin &ge; 4, gentamicin &ge; 4, nalidixic acid &ge; 32 and tetracycline &ge; 4 &mu;g/ml. On the basis of our study results, strains resistant to clindamycin were MIC<sub>R</sub> &ge; 2 &mu;g/ml for the dilution methods and a zone diameter R ≤ 16 mm for the disk diffusion method. Comparison of the results of the resistance examination, a microdilution method and disk diffusion method with the reference agar dilution method, showed that all compared methods yielded identical results with the exception of the resistance determination in erythromycin and nalidixic acid. The errors were mostly the result of the interpretation criteria for MIC<sub>R</sub> of agar dilution method and different conditions of cultivation used. However, the compared methods, provide results comparable with the reference method having greater convenience of measurement.


Author(s):  
Pakhshan A. Hassan ◽  
Adel K. Khider

Acinetobacter baumannii is an opportunistic pathogen that is reported as a major cause of nosocomial infections. The aim of this study was to investigate the biofilm formation by A. baumannii clinical and soil isolates, to display their susceptibility to 11 antibiotics and to study a possible relationship between formation of biofilm and multidrug resistance. During 8 months period, from June 2016 to January 2017, a total of 52 clinical and 22 soil isolates of A. baumannii were collected and identified through conventional phenotypic, chromo agar, biochemical tests, API 20E system, and confirmed genotypically by PCR for blaOXA-51-like gene. Antibiotic susceptibility of isolates was determined by standard disk diffusion method according to Clinical and Laboratory Standard Institute. The biofilm formation was studied using Congo red agar, test tube, and microtiter plate methods. The clinical isolates were 100% resistance to ciprofloxacin, ceftazidime, piperacillin, 96.15% to gentamicin, 96.15% to imipenem, 92.31% to meropenem, and 78.85% to amikacin. The soil A. baumannii isolates were 100% sensitive to imipenem, meropenem, and gentamicin, and 90.1% to ciprofloxacin. All A. baumannii isolates (clinical and soil) were susceptible to polymyxin B. The percentage of biofilm formation in Congo red agar, test tube, and microtiter plate assays was 10.81%, 63.51%, and 86.48%, respectively. More robust biofilm former population was mainly among non-MDR isolates. Isolates with a higher level of resistance tended to form weaker biofilms. The soil isolates exhibited less resistance to antibiotics than clinical isolates. However, the soil isolates produce stronger biofilms than clinical isolates.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Zahra Hashemizadeh ◽  
Nahal Hadi ◽  
Samane Mohebi ◽  
Davood Kalantar-Neyestanaki ◽  
Abdollah Bazargani

Abstract Objectives Molecular typing such as spa typing is used to control and prevent Staphylococcus aureus widespread in hospitals and communities. Hence, the aim of this study was to find the most common types of S. aureus strain circulating in Shiraz via spa and SCCmec typing methods. Results Total of 159 S. aureus isolates were collected from two tertiary hospitals in Shiraz. Isolates were identified by biochemical tests. Antimicrobial susceptibility tests were performed by standard disk diffusion method and then genetic analysis of bacteria was performed using SCCmec and spa typing. In this study 31.4% of the isolates were methicillin-resistant S. aureus. The majority of isolates were SSCmec type III. Spa type t030 was the most prominent type among MRSA strains. For the first time in Iran, spa003, t386, t1877, t314, t186, t1816, t304, t325, t345 were reported in this study. It was shown that there is a possibility that these spa types are native to this region. Our findings showed that SCCmec II, III and IV disseminate from hospital to community and vice versa. Thus, effective monitoring of MRSA in hospital and community is necessary.


2020 ◽  
Vol 12 (01) ◽  
pp. 56-67
Author(s):  
Amit Banik ◽  
Valarie W. Lyngdoh ◽  
Elantamilan Durairaj ◽  
Anil C. Phukan ◽  
Raghavendra Kotal

Abstract Purpose Blood is one of the most important connective tissues of human body. Bloodstream infection can range from inapparent bacteremia till fulminant septic shock with high mortality. Presence of microbes in blood whether continuously, intermittently, or transiently is a grave risk to every organ of body. Culture of blood is a vital tool to diagnose such infections. Drug susceptibility patterns help in rationalizing therapy. Objective The aim of the study is to perform bacteriological analysis and assess drug sensitivity patterns of blood culture isolates and compare in light of other associated variables. Design Retrospective observational study was conducted from January 2009 to December 2013 at a tertiary care hospital at Shillong, India. Blood samples were collected with aseptic guidelines and cultured for 7 days. Growths were identified by standard biochemical tests and subjected to sensitivity testing according to Modified Kirby Bauer disk diffusion method. Data for source of blood collection and duration of incubation were noted and compared. Results A total of 658 (11.2%) pathogens were isolated from 5,867 bacteremia-suspected patient blood specimens. Contamination was observed at the rate of 1.21%. Gram-negative organisms were the predominant pathogens recovered, Klebsiella pneumoniae being the most common. No significant difference was observed between the number of organisms isolated within or beyond 48 hours. Acinetobacter baumannii and K. pneumoniae have significantly higher chances (p < 0.05) of isolation from central line catheters compared with peripheral venipuncture. Conclusion Successful treatment of sepsis depends on early diagnosis and proper antimicrobial therapy. Local knowledge of bacteriological profile and antimicrobial sensitivity patterns helps rationalize empiric treatment strategies.


2018 ◽  
Vol 10 (03) ◽  
pp. 332-337 ◽  
Author(s):  
Amit Banik ◽  
Sanjeev H. Bhat ◽  
Abhay Kumar ◽  
Agnijeet Palit ◽  
Kandregula Snehaa

ABSTRACT PURPOSE: Bloodstream infection can range from inapparent bacteremia until fulminant septic shock with high mortality. Microorganisms present in circulating blood whether continuously, intermittently, or transiently are a threat to every organ in the body. Culture of blood is a vital tool to diagnose such infections. Drug susceptibility patterns help in rationalizing therapy. OBJECTIVE: The objective of this study was to perform bacteriological analysis and assess drug sensitivity patterns of isolates from blood stream infections. DESIGN: Retrospective observational study was conducted from May 2015 to February 2017 at a tertiary care hospital, Port Blair, India. Blood samples were collected with aseptic guidelines and cultured for 7 days. Growths were identified using standard biochemical tests and subjected to sensitivity testing according to Modified Kirby–Bauer’s disk diffusion method. Data for the source of blood collection and duration of incubation were noted and compared. RESULTS: A total of 270 (14.24%) pathogens were isolated from 1895 bacteremia suspect patient blood specimens. Contamination was observed at a rate of 1.63%. Gram-positive cocci (60.37%) were predominant organisms recovered followed by Gram-negative Bacilli (36.29%) and Yeasts (3.33%). Staphylococcus aureus, CoNS, and Acinetobacter spp. were the primary pathogens isolated. Aminoglycosides, carbapenems, and glycopeptides were the most effective drugs for treating bacteremia. CONCLUSIONS: Successful treatment of sepsis depends on early diagnosis and proper antimicrobial therapy. Local knowledge of bacteriological profile and antimicrobial sensitivity patterns helps rationalize empiric treatment strategies.


2020 ◽  
Vol 30 (2) ◽  
pp. 219-226
Author(s):  
S. S. Sobina ◽  
M. O. Zolotov ◽  
A. V. Lyamin ◽  
D. D. Ismatullin ◽  
A. V. Zhestkov

According to the World Health Organization (WHO), diseases caused by Streptococcus pneumoniae are one of the most dangerous diseases, that can be completely prevented by vaccination. Studies conducted in various regions of the Russian Federation and other countries have revealed certain features in the prevalence of pneumococcus strains, resistant to different antibacterial drugs, which requires local studies among patients of different age groups.The aim of the study was to determine the level of sensitivity of S. pneumoniae, isolated from adult patients, to antibacterial drugs (ABD) and the dynamics of resistance to ABD in Samara for the period of 2015–2019.Methods. A retrospective analysis of data from the microbiological department of clinical diagnostic laboratories of the Clinics of Samara State Medical University, Healthcare Ministry of Russia for 2015–2019 was carried out. The microorganism resistance to several groups of ABD was studied – macrolides (erythromycin, azithromycin, clarithro mycin), cephalosporins (ceftriaxone, cefotaxime), fluoroquinolones (levofloxacin) and penicillin. The sensitivity was determined by the disk diffusion method. Statistical processing was performed using the SPSS Statistic 22.0 program. When comparing groups, the χ2 criterion was used; to compare small groups (n < 5), the exact Fisher test was used.Results. Since 2017, there has been a tendency to increase the frequency of pneumococcus isolation in the carrier group. At the same time, a 3-fold decrease in S. pneumoniae excretion from patients with ENT pathology occurred. The highest sensitivity was detected for cephalosporins – 100% sensitivity of all S. pneumoniae strains, detected from ENT organs and during carriage. There is a low level of pneumococcus resistance to levofloxacin. The general sensitivity to ABD from penicillin group is 96.4–98.8%, while the most common resistant strains were found in patients with respiratory tract damage. The highest resistance of S. pneumoniae was revealed to ABD from the macrolide group with a tendency to increase from 4.6% in 2016 to 14.0% in 2019.Conclusion. According to the study results, a rather low level of resistance of S. pneumoniae to most ABD groups, with the exception of macrolides, was demonstrated in Samara. The greatest number of ABD-insensitive pathogens was isolated in patients with pathology of the bronchopulmonary system. A mandatory microbiological examination of the sputum of such patients is necessary with a determination of the sensitivity of the isolated microorganisms to ABD and subsequent correction of therapy upon the identification of resistant strains. Given the increasing resistance of S. pneumoniae in carriers, it is necessary to vaccinate patients in this group. 


Sign in / Sign up

Export Citation Format

Share Document