International Journal of Medical Laboratory

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Background and Aims: The indiscriminate use of antibiotics can lead to antibiotic resistance in the treatment of infections caused by bacteria such as Pseudomonas aeruginosa. The presence of integrons in Pseudomonas is clearly associated with multidrug resistances. Therefore, this study aimed at tracking class I, II and III integrons of antibiotic-resistant isolates of Pseudomonas aeruginosa that were isolated from nosocomial infection.

Materials and Methods: In this study, 51 isolates of Pseudomonas aeruginosa were collected from different wards of Imam Khomeini hospital of Ahvaz since October of 2014 until March of 2015. After identification test and antibigram, coding genes of antibiotic resistance and class I, II and III integrons were detected by polymerase chain reaction (PCR) method.

Results: Tetracycline revealed the most resistance with 84% frequency in discreted isolates. In the encoding antibiotic resistance genes with a frequency of 94% was the most common blaTEM. Class I integron had 92% prevalence, class II Integron showed 52% prevalence and class III Integron demonstrated 17% prevalence.

Conclusions: In Pseudomonas aeruginosa, class I integron was more prevalent than other integrons and the integrase gene was probably one of the causes of multiple antibiotic resistance in this bacteria. Moreover, frequency of integron III  was  reported 17%.

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Background and Aims: Acinetobacter baumannii is regarded as an important nosocomial pathogen around the world, especially in the intensive care unit that today seems to be resistant to the most antibiotics. Therefore, this study aimed to trace classes 1, 2, and 3 integrin in the isolates resistant to Acinetobacter baumannii.

Materials and Methods: In this descriptive study, Acinetobacter baumannii of 67 patients in Ahvaz hospitals were all isolated and their antibiotic resistance pattern was determined by the disk diffusion. The presence of genes coding for antibiotic resistance as well as integrons (class 1, 2 and 3) were analyzed using polymerase chain reaction method.

Results: Out of 67 isolates, the most resistance was observed for the antibiotic tetracycline (89.5%) and the most sensitivity to antibiotic was reported for chloramphenicol, meropenem and nitrofurantoin (2.9%). The distribution of dfrA1, sul1, aac(3)-IV, tet(B), tet(A), aadA1, bla_CITM, vim, qnr, bla_SHV, sim, Oxa-24-like, Oxa-51-like, Oxa-58-like, Oxa-23-like, imp, cmlA and cat1 were 42 (62.6%), 40 (59.7%), 36 (53.7%), 34 (50.7%), 31 (46.2%), 17 (25.3%), 17 (25.3%), 16 (23.8%), 11 (16.4%), 11 (16.4%), 8(11.9%), 5(7.4%), 5(7.4%), 4 (5.9%),4 (5.9%), 4 (5.9%), 2 (2.9%), 1 (1.4%) respectively. Moreover, frequency of class 1, II and III integrons was 67 (100%), 22 (32.8%), and 3 (4.4%) respectively.

Conclusions: High prevalence of integrons among Acinetobater baumannii isolated strains in Ahvaz hospitals indicate the importance role of integrons in multidrug resistance in this bacteria. Therefore, unnecessary use of antibiotics are recommended to be avoided.

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Backgrounds and Aims: Mastitis is a mammalian disease which is considered important due to its potential economic damages. Trueperella pyogenesis is one of the important opportunistic pathogens of the mammary glands of cattle. This bacterium can produce acute mastitis infection in dairy cattle. In fact, this bacterium has several virulence genes which contribute to its pathogenicity. Therefore, this study aimed to determine the frequency of this bacterium in the sick cattle in addition to identifying the effective virulence gene in this disease and finally investigating the antibiotic resistance of T. pyogenes.

Materials and Methods: In total, 126 milk samples from mastitic cows, were collected and immediately transferred to the laboratory. Isolation and identification of T. pyogenes strains were performed using bacteriological methods. Moreover, antimicrobial susceptibility testing was performed using the disk diffusion technique polymerase chain reaction was used to detect plo, fimA, fimC, cbpA, nanH, and nanP virulence genes.

Results: T. pyogenes was detected in 46 milk samples. The expression of plo and fimA virulence genes was observed in all samples while fimC expression was detected in 84.7% of cases. The most resistance was observed against tetracycline (97.8%) and gentamicin (86.9%), whereasthe least resistance was reported for chloramphenicol (4.3%) and nitrofurantoin (10.9%).

Conclusions: T. pyogenes has been regarded as one of the bacteria causing mastitis disease in the cattle. Plo, fimA, and fimC virulence genes seem to be the main virulence factors of this bacterium.

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Background and Aims: The aim of this study was to determine the virulence and antibiotic resistance properties of Streptococcus agalactiae (S. agalactiae) and Streptococcus uberis (S. uberis) isolated from the ruminant’s sub-clinical mastitic milk in Iran.

Materials and Methods: Positive samples in the CMT test were cultured and S. agalactiae and S. uberis have been identified using biochemical tests and polymerase chain reaction (PCR). Virulence and antibiotic resistance genes were studied using PCR. A total of 350 milk samples were collected randomly from 4 major provinces of Iran. We chose 55 bovine, 43 ovine, and 32 caprine herds from these regions.

Results: Totally, 34.52% of bovine, 25% of ovine, and 25% of caprine milk samples were found to be contaminated with S. agalactiae and also, 27.38% of bovine, 25% of ovine, and 25% of caprine milk samples were found to be contaminated with S. uberis. The most commonly detected virulence genes of S. agalactiae were cfb (68.75%), scpB and pavA (43.75%). Also, the most commonly detected pathogenic genes of S. uberis were sua and hasB (83.33%), cfu (75.00%) and skc (70.83%). Totally, tetO (89.28%), ermA (82.14%), mefA (73.21%) and tetM (69.64%) were the most common antibiotic resistance genes in Streptococcus isolates. The most resistance were detected against tetracycline (87.5%) and erythromycin (83.92%), respectively.

Conclusions: Our results showed that animal milk samples should be controlled, especially in colder seasons of the year in order to study the presences of S. agalactiae and S. uberis.

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Background and Aims: Uropathogenic E.coli is one of the most known causes of urinary tract infections, which may lead to a high rate of morbidity and mortality in high risk patients. In this regard, the virulence factors such as bacterial adhesion molecules have a critical role. The current study was intended to determine the molecular properties of adhesion genes in Uropathogenic E.coli strains isolated from hospitalized patients in Babol, north of Iran.
Materials and Methods: During a nine-months of study, 90 Uropathogenic E.coli strains were confirmed by differential biochemical and microbiological standard tests, antimicrobial susceptibility test, and molecular polymerase chain reaction assay were obtained for evaluating the frequency of adhesion genes.
Results: According to the results, the highest rate of resistance and susceptibility were belonged to penicillin and imipenem respectively. On the other hand, the percentage of fimH gene among other virulence genes was reported to be 66%.
Conclusions: The present study showed that a high level of uropathogenic E.coli isolates which harbored the adhesion factors may lead to distribution of multiple antimicrobial resistance strains.