53 research outputs found
Phenotypic Characterization of Escherichia Coli Isolated From Urine and Stool from Short Term and Long Term Catheterized Patients
Background: Uropathogenic strains of Escherichia coli possess a number of phenotypic characters which allow them to colonize the catheter and cause infection of the same and the chances of colonization by these micro-organisms increase with the duration of catheterization. Objectives: This study was carried out to understand the differences between the phenotypic characters between the strains of E.coli isolated from the urine and gut of short term catheterized (STC) and long term catheterized (LTC) patients. Materials and Methods: Urine from the catheter and stool sample was processed by standard methods. The following special tests like α-hemolysis, haemagglutination, cell surface hydrophobicity, serum bactericidal assay, biofilm formation and congo red binding assay were performed to detect the phenotypic characters of the isolated E.coli. Antibiotic susceptibility testing was performed by Kirby Bauer method as per the Clinical Laboratory Standards Institute. Results: Majority (93.75%, 75% and 81.25%) of the E.coli isolates from urine of LTC patients were positive for MRHA, cell surface hydrophobicity and resistant to serum killing respectively, while majority (93.75%) of the urine isolates from short term catheterization. On congo red agar, the majority (80% and 60%) of isolates producing rdar type of colony and biofilm respectively,were isolated from urine of long term catheterized patients. ESBL production was noted in 68.75% of the urine isolates from long term catheterized patients. Conclusion: Serum resistance and biofilm formation are significant assays in terms of differentiating between the short term and long term catheterization and by elucidating these mechanisms better, it may become easier to combat and prevent such infections
The trends of isolation and antimicrobial susceptibility of group B Streptococcus in urine culture: a 7-years cross sectional study
Background: Group B Streptococcus (GBS)/Streptococcus agalactiae (S. agalactiae) is a common rectovaginal colonizer, thereby a potential agent of neonatal and maternal infection. This study estimates the trends of isolation of GBS, its antimicrobial profile in urine culture and the demographic characteristics of these patients over a 7-year period.
Methods: A record-based study was conducted, which included all the urine culture reports of GBS/S. agalactiae from January 2014 to December 2020. The trend of occurrence of GBS bacteriuria, demographic characteristics and antimicrobial susceptibility pattern were analyzed.
Results: Out of 137 urine samples which grew GBS/S. agalactiae, 55(40.15%) were from antenatal women. Most of the isolates were from females (72.26%), with a male preponderance noted among the elderly population (age>60 years). The predominant age group affected were adults between 20 to 59 years. The majority of the isolates (60.58%) were susceptible to all the four tested antibiotics, namely, ciprofloxacin, nitrofurantoin, ampicillin and vancomycin. Ciprofloxacin resistance was observed in 32.85% (45/137) isolates, 5.84% (8/137) isolates were resistant to ampicillin and 2.92% (4/137) were resistant to nitrofurantoin.
Conclusions: All the isolates were susceptible to vancomycin. GBS/S. agalactiae is an important agent of bacteriuria in antenatal women as well as in non-pregnant population, especially the elderly males. Emerging resistance to various group of antibiotics warrants routine susceptibility testing
Characterization of ceftriaxone-resistant Aeromonas spp. isolates from stool samples of both children and adults in Southern India
Background: Aeromonas species can cause a wide spectrum of illnesses
varying from intestinal to extra intestinal and vary in their
susceptibility to different antibiotics. The current study was
undertaken to characterize the third generation cephalosporin-resistant
strains of Aeromonas spp. which were isolated from stool specimens.
Methods: Out of a total of 2780 stool samples, 29 Aeromonas spp. were
identified, out of which, 9 were resistant to ceftriaxone by the
Kirby-Bauer antibiotic testing method. These strains were subjected to
minimum inhibitory concentration (MIC) determination by agar dilution
for ceftriaxone. Phenotypic and genotypic testing of AmpC
beta-lactamase and extended spectrum beta-lactamase (ESBL) were
performed. Gene transfer was carried out to demonstrate
transmissibility of these genetic elements by conjugation experiments.
Results: Out of the 29 strains, 9 showed MIC of 654 \u3bcg/ml.
Seven out of 9 showed presence of blaCTX-M, while 2 more strains showed
the presence of inducible AmpC beta-lactamase and presence of MOX gene.
Gene transfer experiments showed that these elements were transmissible
to recipient ( Escherichia coli J53 strain) in the presence of
ceftriaxone. Conclusions: Dissemination of these resistance
determinants like plasmids is pivotal in the spread of these resistance
genes into the aquatic environment into organisms like Aeromonas. This
may further limit the future use of antibiotics for the treatment of
diarrhoeal diseases. Hence, detection and antibiotic susceptibility
testing of Aeromonas spp. should be performed when isolated from stool
samples
Exacerbation of ulcerative colitis due to Edwardsiella tarda infection
Infectious gastroenteritis can lead to exacerbations of inflammatory bowel disease (IBD) such as ulcerative colitis, which warrants appropriate and timely control with the initiation of specific antibacterial therapy. Herein, we discuss a patient who had presented with an exacerbation of ulcerative colitis due to an infectious gastroenteritis caused by Edwardsiella tarda and had responded to the appropriate antibacterial therapy. This study outlines the importance of a culture of stool samples in all cases of IBD with acute exacerbations
Increasing Antimicrobial Resistance of Vibrio cholerae O1 Biotype El Tor Strains Isolated in a Tertiary-care Centre in India
The antimicrobial susceptibility patterns are on constant change with
the recent emergence of multidrugresistant strains of most bacteria.
Results of recent studies in India showed that most isolates of Vibrio
cholerae O1 were resistant to the commonly-used antibiotics. The
study was conducted to determine the antibiotic susceptibility patterns
of V. cholerae O1 isolated during 2008-2010 at the hospital of the
Jawaharlal Nehru Institute of Post Graduate Medical Education and
Research, Puducherry, India. In total, 154 strains of V. cholerae O1
from 2,658 stool specimens were reported during January
2008\u2013December 2010\u201434 in 2008, 2 in 2009, and 118 in 2010.
The isolates of V. cholerae O1 were subjected to antimicrobial
susceptibility testing using the Kirby-Bauer method. The antibiotic
disks tested were tetracycline (30 \u3bcg), furazolidone (100
\u3bcg), ampicillin (10 \u3bcg), ceftriaxone (30 \u3bcg), and
ciprofloxacin (5 \u3bcg). Escherichia coli ATCC 25922 was used as
the control organism. The minimum inhibitory concentrations (MICs) of
ceftriaxone, ciprofloxacin, and tetracycline were determined using the
agar dilution method for all the strains. The E-test method was used
for the strains which had either intermediate resistance or were
resistant to the antibiotics by the agar dilution method. The results
of the agar dilution corroborated the results of the E-test. The MIC of
ceftriaxone in 151 strains was <2 \u3bcg/mL while it was 16
\u3bcg/mL in three strains; the latter three strains were resistant to
ceftriaxone by the disc-diffusion test. The MIC of ciprofloxacin in 150
strains was <0.5 \u3bcg/mL while the MIC of tetracycline was <1
\u3bcg/mL. In the remaining four strains, the MIC of tetracycline was
>32 \u3bcg/mL, and the MIC of ciprofloxacin was >8 \u3bcg/mL.
These four strains were resistant to both tetracycline and
ciprofloxacin by the disc-diffusion test and were exclusive of the
three ceftriaxone-resistant strains. The majority of the isolates were
obtained from children aged 0-5 year(s)\u201470.3% (83 of 118) and
41.2% (14 of 34) were reported in 2010 and 2008 respectively. Since
treating severe cases of cholera with antibiotics is important, the
continuing spread of resistance in V. cholerae to the most important
agents of therapy is a matter of concern. Also, chemoprophylaxis with
antimicrobial agents is likely to become even more difficult
Clinical and Microbiological Profiles of Shigellosis in Children
Shigellosis presents with varied clinical features are dictated by the
species involved, virulence factors of the strain, and the host immune
status. We studied the species, virulence genes, and antibiotic
susceptibility pattern of the Shigella strains isolated from 33
children aged less than 12 years, with clinical features of
shigellosis. Identification and antibiotic sensitivity of Shigella
species were done using disc diffusion and E-test. Multiplex PCR was
done for the detection of virulence genes (ipaH, ial, set1A, set1B,
sen, and stx) and ESBL genes. Parents of the children were interviewed
using structured questionnaire to assess the severity of the disease;
26 (79%) of the isolates were Shigella flexneri . Ciprofloxacin and
ceftriaxone resistance was seen in 23 (69%) and 3 (9%) Shigella
isolates respectively. Two ceftriaxone-resistant strains were found to
harbour blaCTX gene and the third blaTEM gene. Virulence gene ipaH was
detected in 100% of strains while ial, sen, set1A, and set1B were
detected in 85%, 61%, 48%, and 48% respectively
A study of virulence and antimicrobial resistance pattern in diarrhoeagenic Escherichia coli isolated from diarrhoeal stool specimens from children and adults in a tertiary hospital, Puducherry, India
Background: Emergence of atypical enteropathogenic Escherichia coli
(EPEC) and hybrid E. coli (harboring genes of more than one DEC
pathotypes) strains have complicated the issue of growing antibiotic
resistance in diarrhoeagenic Escherichia coli (DEC). This ongoing
evolution occurs in nature predominantly via horizontal gene transfers
involving the mobile genetic elements like integrons notably class 1
integron. This study was undertaken to determine the virulence pattern
and antibiotic resistance among the circulating DEC strains in a
tertiary care center in south of India. Methods: Diarrhoeal stool
specimens were obtained from 120 children (< 5 years) and 100 adults
(> 18 years), subjected to culture and isolation of diarrhoeal
pathogens. Conventional PCR was performed to detect 10 virulence and 27
antimicrobial resistance (AMR) genes among the E. coli isolated.
Results: DEC infection was observed in 45 (37.5%) children and 18 (18%)
adults, among which [18 (40%), 10 (10%)] atypical EPEC was most
commonly detected followed by [6 (13.3%), 4 (4%)] ETEC, [5 (11.1%) 2
(2%)] EAEC, [(3 (6.6%), 0 (0%)] EIEC, [3 (6.6%), 0 (0%] typical EPEC,
and [4 (8.8%), 1 (1%)] STEC, and no NTEC and CDEC was detected. DEC
co-infection in 3 (6.6%) children, and 1(1%) adult and sole hybrid DEC
infection in 3 (6.6%) children was detected. The distribution of
sulphonamide resistance genes (sulI, sulII, and sulIII were 83.3 and
21%, 60.41 and 42.1%, and 12.5 and 26.3%, respectively) and class 1
integron (int1) genes (41.6 and 26.31%) was higher in DEC strains
isolated from children and adults, respectively. Other AMR genes
detected were qnrS, qnrB, aac(6\u2019)Ib-cr, dhfr1, aadB, aac(3)-IV,
tetA, tetB, tetD, catI, blaCTX, blaSHV, and blaTEM. None harbored qnrA,
qnrC, qepA, tetE, tetC, tetY, ermA, mcr1, int2, and int3 genes.
Conclusions: Atypical EPEC was a primary etiological agent of diarrhea
in children and adults among the DEC pathotypes. Detection of high
numbers of AMR genes and class 1 integron genes indicate the importance
of mobile genetic elements in spreading of multidrug resistance genes
among these strains
Fibre laser development for sensor applications
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Pathogenesis and Laboratory Diagnosis of Childhood Urinary Tract Infection
Urinary tract infection (UTI) is one of the most common infections of childhood. The clinical presentations are mostly non-specific or mild. As any episode of UTI can potentially damage the kidneys, timely diagnosis and treatment are necessary to prevent renal damage. Incidence of UTI varies depending on the age, gender, and race of the child. UTIs in children are commonly caused by bacteria, though viruses, fungi, and parasites are also occasionally involved. The pathogenesis of UTI is complex where several host and pathogen factors influence the course of the disease and its outcome. Urine culture is still considered the gold standard method for the diagnosis of UTI. The means of obtaining urine samples from children for culture involves urethral catheterisation and suprapubic aspiration. The conventional methods of antibiotic susceptibility testing are labour intensive and time exhaustive. With the advent of technology, many automated platforms are available which are rapid, involve less volume of the culture or the sample, and have high accuracy
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