Multiple drug resistant carbapenemases producing Acinetobacter baumannii isolates harbours multiple R-plasmids.

Background & objectives: The nosocomial human pathogen Acinetobacter baumannii has high propensity to develop resistance to antimicrobials and to become multidrug resistant (MDR), consequently complicating the treatment. This study was carried out to investigate the presence of resistant plasmids (R-plasmids) among the clinical isolates of A. baumannii. In addition, the study was performed to check the presence of common β-lactamases encoding genes on these plasmids. Methods: A total of 55 clinical isolates of A. baumannii were included in the study and all were subjected to plasmid DNA isolation, followed by PCR to check the presence of resistance gene determinants such as blaOXA-23, blaOXA-51, blaOXA-58 and blaIMP-1 on these plasmids that encode for oxacillinase (OXA) and metallo-β-lactamase (MBL) type of carbapenemases. Plasmid curing experiments were carried out on selected isolates using ethidium bromide and acridine orange as curing agents and the antibiotic resistance profiles were evaluated before and after curing. Results: All the isolates were identified as A. baumannii by 16SrDNA amplification and sequencing. Plasmid DNA isolated from these isolates showed the occurrence of multiple plasmids with size ranging from 500bp to ≥ 25 kb. The percentage of blaOXA-51 and blaOXA-23 on plasmids were found to be 78 and 42 per cent, respectively and 20 isolates (36%) carried blaIMP-1 gene on plasmids. Significant difference was observed in the antibiograms of plasmid cured isolates when compared to their parental ones. The clinical isolates became susceptible to more than two antibiotic classes after curing of plasmids indicating plasmid borne resistance. Interpretation & conclusions: Our study determined the plasmid mediated resistance mechanisms and occurrence of different resistance genes on various plasmids isolated from MDR A. baumannii. The present findings showed the evidence for antibiotic resistance mediated through multiple plasmids in A. baumannii clinical isolates. This indicates towards a need for preventive measures to avert the dissemination of plasmid resistance determinants in clinical environments.

Correlations between genotyping and antibiograms of clinical isolates of Pseudomonas aeruginosa from three different south Indian hospitals.

Purpose : To compare the molecular relationships and antibiograms of nosocomial isolates of Pseudomonas aeruginosa obtained from three different genres of hospitals located in Southern India, two located at Hyderabad (one private hospital and an ophthalmic hospital) and one in Puducherry (tertiary care teaching hospital). Each of these hospitals, which follow different infection control strategies and various problems associated with it, were investigated. Materials and Methods : Antibiograms generated by disk diffusion susceptibility testing for clinically relevant antibiotics and genotyping through fluorescent amplified fragment length polymorphism analysis (fAFLP) were the tools used in the study. Results: Molecular genotyping revealed a heterogeneous group of unrelated molecular clusters of P. aeruginosa strains having higher resistance that are apparently being endemic throughout the tertiary care teaching hospital. In eye care hospital, only a few distinct strains of P. aeruginosa predominating the study period were shown to be responsible for outbreaks. The third private hospital witnessed a group of resistant and persistent strains that might have clonally originated from a diverse collection of strains. Conclusions : The divergent kind of strains in our study suggests that there may be a direct link between the infection control practices followed in each hospital and kind of strains isolated in that particular setup. The study also emphasizes the need for maintaining infection control practices in hospitals with superior standards, failure of which might result in thriving of persistent P. aeruginosa clones in the hospitals.

Correlation between biofilm production and multiple drug resistance in imipenem resistant clinical isolates of Acinetobacter baumannii.

PURPOSE: To study the qualitative and quantitative methods for the investigation of biofilm formation and to examine the correlation between biofilm and antibiotic resistance among the clinical isolates of Acinetobacter baumannii . We also verified the association between biofilm and presence of extended spectrum beta-lactamases, particularly, bla PER-1 . METHODS: A total of 55 isolates were subjected to susceptibility testing by disc diffusion method for 13 clinically relevant antibiotics. Screening for biofilm production was done by both qualitative and quantitative methods through tube and microtitre plate assay respectively. The presence of bla PER-1 was checked by PCR. RESULTS: A. baumannii isolates showed very high resistance (>75%) to imipenem, cephotaxime, amikacin and ciprofloxacin. Only cefoperazone, netillin and norfloxacin were found to be effective agents. Results of microtitre and tube methods were concordant with 34 isolates (62%) showing biofilm formation. Resistance to four antibiotics such as amikacin (82% vs. 17.6%, P < 0.001), cephotaxime (88% vs. 11%, P P < 0.001), ciprofloxacin (70% vs. 29%, P =0.005) and aztreonam (38% vs. 11%, P =0.039) was comparatively higher among biofilm producers than non-biofilm producers. Microtitre assay additionally detected 14 weakly adherent isolates. Only 11 isolates had bla PER-1 gene and among these two were strong biofilm producers, while remaining were weakly adherent isolates. CONCLUSION: Microtitre plate method was found to be a more sensitive method for biofilm detection. This study demonstrates a high propensity among the clinical isolates of A. baumannii to form biofilm and a significant association of biofilms with multiple drug resistance. Presence of bla PER-1 appears to be more critical for cell adherence than for biofilm formation.

Correlation of endometrial ultrasonography and endometrial histopathology in patients with postmenopausal bleeding.

A retrospective study of 49 cases with persistent postmenopausal vaginal bleeding undergoing hysterectomy in the absence of postoperatively evident diagnosis of genital malignancy was carried out. Normal endometrium was the source of bleeding in 24 cases (48.9%) while 11 cases (22.4%) had evidence of endometritis. Endometrial hyperplasia and polyps were present in 12 cases (24.4%). Two cases were found to have malignancy in the surgical specimen, which were not evident on pre-operative endometrial biopsy. However, there was high degree of suspicion of malignancy in these 2 cases based on the endometrial histopathology and ultrasonographic endometrial thickness. By careful correlation of clinical findings, endometrial histopathology and ultrasound measurement of endometrial thickness, most cases with postmenopausal bleeding can be managed conservatively.

Malignant chondroid syringoma.

An adult female presented with a painful recurrent swelling on the posterior aspect of the scalp of six months' duration, which was clinically diagnosed as fibroma. An excision biopsy showed anaplastic epithelial cells arranged in irregular cords and trabeculae, mitosis, malignant chondroid areas, desmoplasia and perineural invasion, suggesting malignancy. Wide excision of the tumor was the only treatment given since there was no metastasis.

Bronchioloalveolar carcinoma mimicking miliary tuberculosis.

A case of bronchioloalveolar carcinoma, with widespread dissemination to both lungs and miliary mottling on chest X-ray is reported in a 40 year old male.

Acquired immunodeficiency syndrome presenting as testicular tuberculosis.

A 50 year old heterosexual male presented with fever and cough with expectoration of months duration, and swelling in the right testis. The serological tests showed positivity for HIV 1 and 11 antibodies. Testicular biopsy from the right testis showed epitheloid cell granulomas with central caseous necrosis and peripheral mantle of lymphocytes and plasma cells. Zeihl-Neelsen stain on tissue sections showed AFB positivity. To the best of our knowledge this is the second reported case of acquired immunodeficiency syndrome presenting as testicular tuberculosis.

Chediak-Higashi syndrome.

A case of Chediak-Higashi syndrome is reported in a four-year-old boy who presented with recurrent chest infection, partial albinism, hyperpigmentation of the extremities and presence of giant granules in leucocytes and melanocytes in the skin. Parental consanguinity was present. Though uncommon, hyperpigmentation of sun exposed areas may be the initial symptom in Chediak-Higashi syndrome.

Meningeal carcinomatosis complicating ovarian malignancy.

A case of meningeal carcinomatosis following ovarian carcinoma is reported. The rarity of this occurrence is highlighted.