scholarly journals Identification and detection of pathogenic bacteria from patients with hospital-acquired pneumonia in southwestern Iran; evaluation of biofilm production and molecular typing of bacterial isolates

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Farzad Mazloomirad ◽  
Sajad Hasanzadeh ◽  
Asghar Sharifi ◽  
Gordafarin Nikbakht ◽  
Narges Roustaei ◽  
...  
Keyword(s):  
Molecular Typing ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Typing Method ◽  
Gram Negative ◽  
E Coli ◽  
Type Iii ◽  
Hospital Acquired Pneumonia ◽  
Southwestern Iran ◽  
Hospital Acquired

Abstract Background Hospital-acquired pneumonia (HAP) is the second most common nosocomial infection in intensive care units (ICUs). The present study aims to determine the prevalence of pathogenic bacteria, their biofilm formation, and molecular typing from patients with HAP in southwestern Iran. Methods Fifty-eight patients with HAP participated in this cross-sectional study. Sputum and endotracheal aspirate were collected from each patient for isolation and detection of bacteria. Biofilm formation was evaluated using Congo red agar or Microtiter plate assay. The antimicrobial susceptibility patterns of the isolates were investigated. The multiplex polymerase chain reaction (M-PCR) technique was used to determine the Staphylococcal Cassette Chromosome mec (SCCmec) types of methicillin-resistant Staphylococcus aureus (MRSA) strains. All S. aureus isolates were typed using the agr typing method. A repetitive element sequence-based PCR (rep-PCR) typing method was used for typing of Gram-negative bacteria. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software version 15 and the chi-square test. Results Bacteria were isolated in 52 (89.7%) of patients. Acinetobacter baumannii (A. baumannii) was the most prevalent organism (37%), followed by S. aureus, Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli). Using the PCR method, 56 bacteria were detected. A. baumannii was the most prevalent (35.7%) organism. A. baumannii and P. aeruginosa were biofilm-producing. All Gram-negative isolates were colistin-sensitive, and most of the A. baumannii isolates were multidrug-resistant (MDR). MRSA was identified in 12 (80%) S. aureus isolates, and 91.6% of MRSA were SCCmec type III. The agr type III was the most predominant. The rep-PCR analysis showed seven different patterns in 20 A. baumannii, six patterns in 13 P. aeruginosa, and four patterns in 6 E. coli. Conclusion A. baumannii was more prevalent than S. aureus in ventilator-associated pneumonia (VAP), while S. aureus is a major pathogen in non-ventilator hospital-acquired pneumonia (NV-HAP), possibly due to the tendency of the former to aquatic environments. Based on the rep-PCR typing method, it was concluded that bacteria were transmitted from patients or healthcare workers among different wards. Colistin can be used as a treatment in Gram-negative MDR isolates.

scholarly journals Identification and Detection of Pathogenic Bacteria From Patients With Hospital Acquired Pneumonia in Southwest of Iran; Evaluation of Biofilm Production and Molecular Typing of Bacterial Isolates

2021 ◽  
Author(s):  
Farzad Mazloomirad ◽  
Sajad Hasanzadeh ◽  
Asghar Sharifi ◽  
Gordafarin Nikbakht ◽  
Narges Roustaei ◽  
...  
Keyword(s):  
Molecular Typing ◽  
Pathogenic Bacteria ◽  
Culture Method ◽  
Microtiter Plate ◽  
Clinical Samples ◽  
Pcr Analysis ◽  
Typing Method ◽  
Cross Sectional ◽  
Gram Negative ◽  
Biofilm Production

Abstract BackgroundHospital acquired pneumonia (HAP) HAP is the most second nosocomial infection and the most common infection in the intensive care unit. The aim of the present study was to determine the prevalence of pathogenic bacteria, their biofilm formation and molecular typing in sputum samples from patients with HAP in southwest of Iran.MethodsIn this cross-sectional study, 58 patients with HAP were included in this study. Clinical samples including sputum andendotracheal aspirate collected from each patient under aseptic conditions and were sent to the Microbiology Laboratory.Isolation and detection of bacteria were performed by culture and polymerase chain reaction methods.Biofilm formation was evaluated using by Congo red Agar or microtiter plate assay.A rep- PCR typing method was used for typing of gram-negative bacteria. MRSA isolates were typed using SCCmec typing method. Data were analyzed by SPSS software version 15 and chi-square test.ResultsUsing culture method, bacteria identified in 52 (89.7 %) of patients. Acinetobacter baumannii was the most prevalent (37%) organism and followed by Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. All of the A. baumannii and P. aeruginosa were biofilm producer. 12 cases (80%) of S. aureus isolates were MRSA and 91.6% of MRSA were SCCmec type III. The rep -PCR analysis showed 7 different patterns in 20 A. baumannii, 6 patterns in 13 P. aeruginosa and 4 patterns in 6 E. coli. Most of the A. baumanii isolates were multi drug resistant. ConclusionA. baumanii was more prevalent in VAP, while S. aureus as a major pathogen in N- VAP that maybe related to tendency of A. baumannii to the aquatic environment. Biofilm production ability in bacteria increased antibiotic resistance, development of chronic and persistent infection in HAP. Based on rep- PCR typing method we concluded that bacteria transmitted from patients or health care workers among different wards of hospital. Colistin can be used as a treatment in gram negative MDR isolates.

scholarly journals Factors influencing mortality in hospital-acquired pneumonia caused by Gram-negative bacteria in China

2019 ◽  
Vol 12 (5) ◽  
pp. 630-633 ◽  
Author(s):  
Ding-Yun Feng ◽  
Yu-Qi Zhou ◽  
Xiao-Ling Zou ◽  
Mi Zhou ◽  
Wen-Bin Wu ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Factors Influencing ◽  
Hospital Acquired Pneumonia ◽  
Hospital Acquired

Microbiology of Ventilator–Associated Pneumonia Compared With That of Hospital-Acquired Pneumonia

2007 ◽  
Vol 28 (7) ◽  
pp. 825-831 ◽  
Author(s):  
David J. Weber ◽  
William A. Rutala ◽  
Emily E. Sickbert-Bennett ◽  
Gregory P. Samsa ◽  
Vickie Brown ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Empirical Therapy ◽  
Ventilator Associated Pneumonia ◽  
Gram Positive ◽  
Similar Frequency ◽  
Gram Negative ◽  
Hospital Acquired Pneumonia ◽  
Hospital Acquired ◽  
Gram Positive Cocci ◽  
Ventilated Patients

Objective.Nosocomial pneumonia is the leading cause of mortality attributed to nosocomial infection. Appropriate empirical therapy has been associated with improved survival, but data are limited regarding the etiologic agents of hospital-acquired pneumonia in non-ventilated patients (HAP). This evaluation assessed whether the currently recommended empirical therapy is appropriate for both ventilator-associated pneumonia (VAP) and HAP by evaluating the infecting flora.Design.Prospectively collected hospitalwide surveillance data was obtained by infection control professionals using standard Centers for Disease Control and Prevention definitions.Setting.A tertiary care academic hospital.Patients.All patients admitted from 2000 through 2003.Results.A total of 588 episodes of pneumonia were reported in 556 patients: 327 episodes of VAP in 309 patients, and 261 episodes of HAP in 247 Patients. The infecting flora in ventilated patients included gram-positive cocci (32.0% [oxacillin-susceptible Staphylococcus aureus {OSSA}, 9.25%; oxacillin-resistant Staphylococcus aureus {ORSA}, 17.75%]), gram-negative bacilli (59.0% {Pseudomonas aeruginosa, 17.50%; Stenotrophomonas maltophilia, 6.75%; Acinetobacter species, 7.75%), and miscellaneous pathogens (9.0%). The infecting flora in nonventilated patients included gram-positive cocci (42.59% [OSSA, 13.33%; ORSA, 20.37%]), gram-negative bacilli (39.63% [P. aeruginosa, 9.26%; S. maltophilia, 1.11%; Acinetobacter species, 3.33%), and miscellaneous pathogens (17.78%).Conclusions.Our data demonstrated that patients with HAP, compared with those with VAP, had a similar frequency of infection with ORSA but less commonly had infections due to P. aeruginosa, Acinetobacter species, and S. maltophilia. However, the overall frequency of infection with these pathogens was sufficiently high to warrant the use of empirical therapy likely to be active against them. Our data supports using the currently recommended empirical therapy for both HAP and VAP.

Escherichia coli tol and rcs genes participate in the complex network affecting curli synthesis

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2487-2497 ◽  
Author(s):  
Anne Vianney ◽  
Grégory Jubelin ◽  
Sophie Renault ◽  
Corine Dorel ◽  
Philippe Lejeune ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Membrane Integrity ◽  
Regulatory Proteins ◽  
Gram Negative Bacteria ◽  
Dependent Manner ◽  
Dominant Effect ◽  
Gram Negative ◽  
E Coli

Curli are necessary for the adherence of Escherichia coli to surfaces, and to each other, during biofilm formation, and the csgBA and csgDEFG operons are both required for their synthesis. A recent survey of gene expression in Pseudomonas aeruginosa biofilms has identified tolA as a gene activated in biofilms. The tol genes play a fundamental role in maintaining the outer-membrane integrity of Gram-negative bacteria. RcsC, the sensor of the RcsBCD phosphorelay, is involved, together with RcsA, in colanic acid capsule synthesis, and also modulates the expression of tolQRA and csgDEFG. In addition, the RcsBCD phosphorelay is activated in tol mutants or when Tol proteins are overexpressed. These results led the authors to investigate the role of the tol genes in biofilm formation in laboratory and clinical isolates of E. coli. It was shown that the adherence of cells was lowered in the tol mutants. This could be the result of a drastic decrease in the expression of the csgBA operon, even though the expression of csgDEFG was slightly increased under such conditions. It was also shown that the Rcs system negatively controls the expression of the two csg operons in an RcsA-dependent manner. In the tol mutants, activation of csgDEFG occurred via OmpR and was dominant upon repression by RcsB and RcsA, while these two regulatory proteins repressed csgBA through a dominant effect on the activator protein CsgD, thus affecting curli synthesis. The results demonstrate that the Rcs system, previously known to control the synthesis of the capsule and the flagella, is an additional component involved in the regulation of curli. Furthermore, it is shown that the defect in cell motility observed in the tol mutants depends on RcsB and RcsA.

scholarly journals Antibiotic susceptibility of intra-abdominal infection isolates from Indian hospitals during 2008

2010 ◽  
Vol 59 (9) ◽  
pp. 1050-1054 ◽  
Author(s):  
Stephen P. Hawser ◽  
Robert E. Badal ◽  
Samuel K. Bouchillon ◽  
Daryl J. Hoban ◽  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Gram Negative ◽  
E Coli ◽  
Abdominal Infection ◽  
Intra Abdominal Infection ◽  
Abdominal Infections ◽  
Hospital Acquired ◽  
Very High

A total of 542 clinical isolates of aerobic Gram-negative bacilli from intra-abdominal infections were collected during 2008 from seven hospitals in India participating in the Study for Monitoring Antimicrobial Resistance Trends (SMART). Isolates were from various infection sources, the most common being gall bladder (30.1 %) and peritoneal fluid (31.5 %), and were mostly hospital-associated isolates (70.8 %) as compared to community-acquired (26.9 %). The most frequently isolated pathogens were Escherichia coli (62.7 %), Klebsiella pneumoniae (16.7 %) and Pseudomonas aeruginosa (5.3 %). Extended-spectrum β-lactamase (ESBL) rates in E. coli and K. pneumoniae were very high, at 67 % and 55 %, respectively. Most isolates exhibited resistance to one or more antibiotics. The most active drugs were generally ertapenem, imipenem and amikacin. However, hospital-acquired isolates in general, as well as ESBL-positive isolates, exhibited lower susceptibilities than community-acquired isolates. Further surveillance monitoring of intra-abdominal isolates from India is recommended.

scholarly journals The Ax21 protein influences virulence and biofilm formation in the nosocomial pathogen Stenotrophomonas maltophilia

2017 ◽  
Author(s):  
Shi-qi An ◽  
Ji-liang Tang
Keyword(s):  
Antibiotic Resistance ◽  
Plant Pathogen ◽  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Xanthomonas Oryzae ◽  
Nosocomial Pathogen ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Hospital Acquired Infection ◽  
Hospital Acquired

Stenotrophomonas maltophilia is an antibiotic resistant Gram-negative pathogen, which is associated with hospital-acquired infection. The genome encodes a protein highly related to the Ax21 protein of Xanthomonas oryzae pv. oryzae that is implicated in interactions of this plant pathogen with rice. Here we show that loss by mutation of Ax21 influences a variety of functions in Stenotrophomonas maltophilia, to include virulence, antibiotic resistance and biofilm formation in this nosocomial pathogen.

scholarly journals Biosynthesized Zinc Oxide Nanoparticles Disrupt Established Biofilms of Pathogenic Bacteria

2022 ◽  
Vol 12 (2) ◽  
pp. 710
Author(s):  
Fohad Mabood Husain ◽  
Faizan Abul Qais ◽  
Iqbal Ahmad ◽  
Mohammed Jamal Hakeem ◽  
Mohammad Hassan Baig ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Pathogenic Bacteria ◽  
Oxide Nanoparticles ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Zno Nps ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Global emergence and persistence of the multidrug-resistant microbes have created a new problem for management of diseases associated with infections. The development of antimicrobial resistance is mainly due to the sub-judicious and unprescribed used of antimicrobials both in healthcare and the environment. Biofilms are important due to their role in microbial infections and hence are considered a novel target in discovery of new antibacterial or antibiofilm agents. In this article, zinc oxide nanoparticles (ZnO-NPs) were prepared using extract of Plumbago zeylanica. ZnO-NPs were characterized and then their antibiofilm activity was tested against Gram-positive and Gram-negative bacteria. The ZnO-NPs were polydispersed, and the average size was obtained as 24.62 nm. The presence of many functional groups indicated that phytocompounds of P. zeylanica were responsible for the synthesis, capping, and stabilization of ZnO-NPs. Synthesized NPs inhibited the biofilm formation of E. coli, S. aureus, and P. aeruginosa by 62.80%, 71.57%, and 77.69%, respectively. Likewise, concentration-dependent inhibition of the EPS production was recorded in all test bacteria. Microscopic examination of the biofilms revealed that ZnO-NPs reduced the bacterial colonization on solid support and altered the architecture of the biofilms. ZnO-NPs also remarkably eradicated the preformed biofilms of the test bacteria up to 52.69%, 59.79%, and 67.22% recorded for E. coli, S. aureus, P. aeruginosa, respectively. The findings reveal the ability of green synthesized zinc oxide nanoparticles to inhibit, as well as eradicate, the biofilms of Gram-positive and Gram-negative bacteria.

scholarly journals Survey of Toxin–Antitoxin Systems in Erwinia amylovora Reveals Insights into Diversity and Functional Specificity

Toxins ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 206
Author(s):  
Teja Shidore ◽  
Quan Zeng ◽  
Lindsay Triplett
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Erwinia Amylovora ◽  
Plasmid Stability ◽  
Hidden Markov ◽  
Cytoskeletal Proteins ◽  
Type Ii ◽  
Functional Specificity ◽  
E Coli

Toxin–antitoxin (TA) systems are diverse genetic modules with demonstrated roles in plasmid stability, stress management, biofilm formation and antibiotic persistence. However, relatively little is known about their functional significance in plant pathogens. In this study we characterize type II and IV TA systems in the economically important plant pathogen Erwinia amylovora. Hidden Markov Model (HMM) and BLAST-based programs were used to predict the identity and distribution of putative TA systems among sequenced genomes of E. amylovora and other plant-associated Erwinia spp. Of six conserved TA systems tested for function from E. amylovora, three (CbtA/CbeA, ParE/RHH and Doc/PhD) were validated as functional. CbtA was toxic to E. amylovora, but not to Escherichia coli. While the E. coli homolog of CbtA elicits the formation of lemon-shaped cells upon overexpression and targets cytoskeletal proteins FtsZ and MreB, E. amylovora CbtA led to cell elongation and did not interact with these cytoskeletal proteins. Phylogenetic analysis revealed that E. amylovora CbtA belongs to a distinct clade from the CbtA of pathogenic E. coli. This study expands the repertoire of experimentally validated TA systems in plant pathogenic bacteria, and suggests that the E. amylovora homolog of CbtA is functionally distinct from that of E. coli.

Effect of Trans-Cinnamaldehyde on preformed biofilm and biofilm formation of Escherichia coli isolated from urine specimens

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Eman Adel El-Haddad ◽  
Soha Abdel Rahman El-Hady ◽  
Amira Esmail Abdel Hamid ◽  
Hisham Abdel Majeed Fahim
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Defense Mechanisms ◽  
Colorimetric Assay ◽  
Biofilm Inhibition ◽  
Hospital Acquired Infection ◽  
E Coli ◽  
Before And After ◽  
Tract Infections ◽  
Hospital Acquired

Abstract Introduction Bacteria in most environments exist as communities of sessile cells in a selfproduced polymeric matrix known as biofilms. Biofilms are responsible for more than 80% of infections, including urinary tract infections (UTI). UTI is the most common hospital acquired infection, caused mainly by Escherichia coli (E.coli). E. coli can readily form biofilm in such infections, specially in the presence of indwelling urinary catheter. It’s difficult to eradicate bacteria in biofilms, since they are shielded from the host defense mechanisms as phagocytes and antibodies, as well as antibiotics. Searching for alternative or adjuvant substances for prevention and eradication of biofilm associated infections are therefore urgently needed. Aim of the work Studying the efficacy of the trans-cinnamaldehyde (TC) for preventing E. coli biofilm formation. Materials and methods Thirty isolates of E.coli were obtained from urine samples. To test the effect of TC on E.coli biofilm formation and preformed biofilms, microtitre plates (MTP) were inoculated with the isolated E.coli and were treated with different concentrations of TC and incubated at 37° C. A colorimetric assay was used to assess biofilm inhibition and inactivation and optical densities (OD) were compared before and after adding different TC concentrations. Results The mean OD of the isolated E.coli biofilms was 1.3 and significantly decreased when mixed with TC different concentrations. TC had high activity in inhibition of preformed E.coli biofilms, where no biofilm was detected on MTP treated with 1.25% and 1.5% TC. Conclusion TC inhibited the biofilm forming ability of E.coli isolates could fully inactivate formed biofilms, suggesting its possibility to be used as an anti-biofilm agent or adjuvant in preventing and treating UTI caused by biofilm producing E.coli.

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