Archive for the ‘ Microbiology ’ Category

Prevalence of ABO and rhesus (D) antigens with possible transfusion transmitted infections in correlation to rhesus and ABO blood group systems


Objective: The objective was to study the frequency of ABO and Rh (D) blood groups and its correlation to transfusion transmitted infections (TTI) among the blood donors who donated at Vinayaka Mission’s Kirupananda Variyar blood bank, Salem, Tamilnadu.
Materials and Methods: Details about blood grouping and TTI positivity of a total of 17678 potential blood donors were collected from the records of transfusion medicine department of our institution for 3 years period between July 2011 and June 2014. Results: Blood group ‘B’ had the highest incidence and 93.33% of the blood groups tested were Rh positive. ‘A’ blood group with Rh positivity was more commonly associated with TTI.
Conclusion: The most common blood group tested in our blood bank was ‘B positive,’ whereas TTI was common in the ‘A positive’ blood donors.

Mupirocin resistance in nasal isolates of Staphylococci from health care workers


Context: Application of mupirocin to the anterior nares of patients colonized with Staphylococci eliminates the carriage of these organisms and is important in preventing the spread and development of Staphylococcal infection. There are several reports of Staphylococcal resistance to mupirocin.

Aim: This study was carried out primarily to determine the prevalence of low level and high-level mupirocin resistance in Staphylococcus aureus and coagulase-negative Staphylococci (CONS) and secondarily to compare its association with methicillin resistance.

Materials and Methods: Study sample included nasal swabs from a total of 206 subjects, which consisted of 104 medical students and 102 health care workers. Resistance to mupirocin was detected by disc diffusion method of Kirby Bauer using 5 μg and 200 μg mupirocin discs. Statistical analysis was done by Z test.

Results: In the present study, low-level mupirocin resistance was seen in 1 (2.23%) of methicillin-resistant Staphylococcus aureus (MRSA) and 3 (4.92%) of methicillinresistant CONS (MRCONS). High-level mupirocin resistance was seen in 2 (4.45%) of MRSA, 1 (1.58%) of methicillin- sensitive CONS, and 10 (16.39%) MRCONS isolates.

Conclusions: Overall mupirocin resistance in Staphylococcal isolates is still low. It is more prevalent in MRCONS species.



Ascariasis is the intestinal parasitic infection caused by Ascaris lumbricoides (roundworm). Its highest prevalence is observed in the tropical and subtropical areas. In contrast to silent forms of this illness or chronic symptomatology, massive infestation in children can lead to serious complications like intestinal obstruction requiring urgent surgical attention. We report a seven year old female child with severe sequelae of intestinal obstruction.



Background: The resistance to antimicrobial agents among Staphylococci is an increasing problem. Clinical failure of clindamycin therapy has been reported due to multiple mechanisms that confer resistance to macrolide, lincosamide and streptogramin antibiotics.
In-vitro, routine tests for clindamycin susceptibility may fail to detect inducible clindamycin resistance due to erm genes resulting in treatment failure, thus necessitating the need to detect such resistance by a simple D-test on a routine basis.
Aim: The aim of the study was to assess the frequency of inducible clindamycin resistance in clinical isolates of Staphylococci by using D-test on a routine basis to guide therapy.
Materials & Methods: A total of 108 Staphylococcus species were isolated from various clinical samples received in the microbiology department over a period of one year (February 2011 – January 2012) and were subjected to the study. Inducible clindamycin resistance was tested in these isolates by D-test as per CLSI guidelines.
Results: Among the 108 Staphylococci isolates, 32 (29.62 %) showed inducible clindamycin resistance and belonged to iMLS phenotype. All 32 isolates were B Methicillin Resistant Staphylococcus aureus (MRSA).
Conclusion: The study showed that D-test should be used as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance in Staphylococci for the proper treatment of the patients.



Healthcare-Associated Infections (HAI) are a major cause of morbidity and mortality. Standard Infection control practices are very important in reducing the incidence of HAI. The aim of this study was to assess infection control measures and its impact in the Medical Intensive Care Unit (MICU) of a tertiary care hospital. The Infection control practices studied include Hand hygiene practices, use of Personal Protective Equipment, Environmental Cleaning and Disinfection, Waste segregation and disposal, Aseptic precaution during Intravenous Cannulation, Urinary Catheterization and Ventilator care. Strict implementation of the Infection control practices resulted in a decrease in the HAI rate. So it is mandatory to have an effective infection control programme in every hospital.



Background: The conventional techniques like smear microscopy and culture suffer from low sensitivity for diagnosis of extra-pulmonary TB (EPTB). Polymerase Chain Reaction (PCR) is presently seen as a promising alternative to conventional techniques. This study evaluates IS6110 sequence based nested PCR (nPCR) for the detection of Mycobacterium tuberculosis (MTB) DNA directly from clinical samples of extra-pulmonary origin.
Material and Methods: A total of 120 extra-pulmonary samples from the patients with history suggestive of tuberculosis were taken. All the samples were processed for Ziehl-Neelsan staining for acid fast bacilli (AFB), culture and PCR with primers targeting 123bp fragment of IS6110 of MTB complex.
Results: A significant difference was seen in the sensitivities of conventional methods and PCR (p<0.05). Out of these 120 samples 14 (11.7%) were positive by smear, culture was positive in 16 (13.3%) samples. Eithersmear or culture positive 18 (15%) and 39 (32.5%) were positive by PCR.
Conclusions: The nPCR assay targeting IS6110 gene sequence is a rapid and sensitive diagnostic technique for detection of M. tuberculosis genome in clinically suspected extra-pulmonary tuberculosis specimens, as compared to the conventional techniques.



Introduction: – Dengue is a major health problem in many parts of the tropical world. It is a mosquito borne illness caused by one of the serotypes of dengue viruses.
Aims and objectives: – The present study was done to
know the common clinical features and Seroprevalence of dengue in our region. An attempt was made to compare rapid test SD dengue duo (IgM, IgG & NS-1 Ag detection) with capture ELISA (IgM, IgG Microlisa

Materials & Methods: – 226 serum samples were tested in patients clinically suspected Dengue. All the 226 samples were subjected to IgG, IgM Microlisa test. The same were put on rapid SD bioline Dengue duo rapid test and was compared with ELISA.
Results:- 226 serum samples were tested in patients clinically suspected Dengue before noting common clinical signs and symptoms. 150 samples were tested positive with ELISA (either positive for IgG, IgM or both). Seroprevalence of 66% were reported. When compared with ELISA, Rapid test showed sensitivity of 80.6% specificity and positive predictive value of 100% & zero false positive rates. Efficiency of the test was 87.16%
Conclusion:- High prevalence rate in our region particularly in premonsoon & monsoon season gives an alarm to the doctors regarding early and accurate diagnosis of dengue virus infection. SD Dengue duo rapid test should be a valuable screening test for dengue fever
which can be interpreted easily. Results were comparable to ELISA. It provides additional diagnostic investigation that compliments NS-1 antigen detection.



Tuberculous cerebellar abscess is highly uncommon and serious form of extra pulmonary tuberculosis. Here we present a case of Tuberculous cerebellar abscess without history of pulmonary tuberculosis, in a 50 year old male, being a factory employee, immunocompetent patient with chief complaints of headache, slurred speech, unsteadiness of GAIT, swaying to side, dysphagia of 6
months duration. Diagnosiswasmadeby contrast CT scan of brain and confirmed by bacteriological examination of pus drained by craniotomy.



Dengue and Chikungunya virus illness affects tropical and subtropical regions around the world including India. In Delhi,a highly populous city, as recently as in the year 2010, several cases of fever with clinical picture similar to that of dengue and chikungunya virus infection eported in our Vardhman Mahavir Medical College & associated Safdarjang Hospital, New Delhi. Cases of fever started reporting in late June, 2010 but fromSeptember onwards also emerged cases of chikungunya. On clinical basis alone, especially during mixed outbreaks, it is generally difficult to differentiate between the two, in particular when dengue fever does not manifest as DHF. Serology
for dengue and chikungunyawas performed byMacELISA test with the aim as detection of specific IgM antibodies. In cases of dengue fever from late June till end August – 2010, the IgM seropositivitywas found to be 38.3%. From September, 2010 onwards and till December end, in cases of chikungunya virus fever the IgM seropositivity was found to be 65.11% and that of dengue as 37.86%. Also, in cases from Sep to Dec, 2010, which presented with clinical pictures suggestive of both types of viral infections, revealed that the seropositivity for dengue declined to 8.36%, and for Chikungunya increased to 41.46%. In conclusion, the dengue outbreak, especially in city Delhi, may get overwhelmingly replaced by chikungunya virus fever cases with both the dominant viruses’ co circulating in the community. Detection of IgM antibodies against dengue and chikungunya by ELISA during the mixed outbreak appears to play important role for distinguishing the two, and reinforces clinical diagnosis, and, hence, helps initiate proper medical care.



Background : Intravascular catheters are used to infuse medicines, blood products, nutrition or to provide access for hemodynamic monitoring. Placement of the device through the skin and into a blood vessel bypasses one of the body’s best barriers to infection and creates the potential for micro-organisms to enter the blood directly. Purpose: to confirm that the catheter is the source of infection and to identify the organism so that the therapeutic decisions can be made.

Material and methods : Distal 1.5-2 inches of the catheters are rolled on culture plates. Complete identification and susceptibility testing was performed when 1or 2 organism typesarepresentat isequal to 15 colonies.

Result:out of 54 catheter tips, 43 showed bacterial growth Coagulase negative Staphylococcus 51.16%, Staphylococcus aureus 32.56%, Klebsiella pneumoniae 4.65%, Gramnegative bacilli 2.33% and Candida 2.33%.

Conclusion: catheter related sepsis is a common complication of modern medical therapy. Reduction of this complicationmay be achieved by optimising IV access and careful monitoring.


The study aims at finding the prevalence, antifungal susceptibility and co – relation of Candida infection with CD4 count amongst the Human Immunodeficiency Virus (HIV) positive patients suspected to be suffering from oropharyngeal candidiasis (OPC) in Manipur.
Oropharynge a l swabs f rom 100 Acquired Immunodeficiency Syndrome (AIDS) patients were processed by observing under direct 10% Potassium hydroxide (KOH) mount for presence of yeast cells, culture on 2 Sabouraud’s Dextrose Agar (SDA) with chloramphenicol incubated at 37˚C and 25˚C for 2 weeks. Antifungal susceptibility was done by the disc diffusion method. Candida – 40 (62.5%) was the commonest species. Fluconazole resistance was encountered in -23(36%) of the Candida isolates. OPC in HIV positive was seen maximum in patients having CD4 count of < 100 cells/μl .


Background: Brucellae are small Gram negative coccobacilli known to cause brucellosis, the most common zoonotic disease world wide .The multisystem involvement and the protean and unusual clinical presentation of the disease pose significant diagnostic challenge. Although isolation of the causative organism is the definitive proof of the disease etiology practical difficulties are encountered. Hence serological tests remain the most commonly used method for its laboratory diagnosis. Standard tube agglutination test (STT) is the conventional serological test used.

Aim: The present study was carried out to evaluate the two different antigenic preparations from smooth stains of for standardizing enzyme linked immunosorbant assay (ELISA) and Indirect Haemagglutination assay (IHA) as an alternative for STT. Standard tube agglutination test antigen and Standard antibrucella serum obtained from IVRI, Izathnagar were used as controls for standardization of ELISAand IHA .

Materials and methods: Sonicated lipopolysaccharide antigen (LPS-SE) and heat extracted lipopolysaccharide antigen (LPS-HE) [evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) ] were used to coat the micro titre plates for ELISAaswell as IHA.Eighty one human sera frompeople working in organized farms (cases) and 100 apparently healthy persons whose serum samples were sent for routine heamatological investigations (controls) were taken for the study. All the serum samples (cases and controls) were tested by Standard tube agglutination test (STT).

Statistical analysis: The Statistical software namely SAS 9.2, SPSS 15.0, Stata 10.1, MedCalc 9.0.1 ,Systat 12.0 and  Renvironment ver.2.11.1 were used.

Results and conclusion: ELISA showed a good sensitivity (100%) and specificity of 95.95 and 97.30 respectively for
both the antigens whereas IHA showed high specificity and low sensitivity when compared to ELISA ie a specificity of 98.65 for LPS –HE and sensitivity of 85.71 for LPS-SE. However it was concluded that ELISA is slightly superior to IHA as far as sensitivity is concerned.It is cheap, sensitive reproducible and specific assay for serological diagnosis of brucellosis.


Severe thrombocytopenia and acute renal   failure, once considered to be exclusively due to P.falciparum were observed recently in P.vivax infection also. Early diagnosis and appropriate treatment is the basis to prevent complications. Diagnosis , solely based on clinical symptoms is unreliable. Microscopist is not available everywhere and reliability is also questionable. So a simple alternative test is required for the present situation.The present study is to compare microscopy with Ag detection ICT during an epidemic and to document ARF and thrombocytopenia with P.vivax infection in endemic area.78 patients were screened for malaria during the epidemic from December 2009 and January 2010. Malaria Ag detection ICT was used alongside the gold standard microscopy.Total patients screened = 78 .Positive by thick smear : 23 (30%) i.e., P.vivax-20(26%), P.falciparum  3(4%) Positive by Ag detection ICT : 34 (44%) i.e, P.vivax22(28%) P.falciparum12(15%) Sensitivity (ICT) 95.83%, Specificity  (ICT) 79.82%, Thrombocytopenia : P.vivax – 7 out of 22 (32%)P.falciparum – 7 out of 12 (58%) Acute renal failure– P.vivax -2 out of 7, P.faciparum – 1 out of 12 . Both the tests became negative in 6 patients (1 P.falciparum & 5 P.vivax)who camefor follow up in aweek period.P.vivax also should be considered in patients with severe thrombocytopenia and acute renal failure. Employing rapid Ag detection ICT in endemic areas will reduce the indiscriminate use of anti malarial drugs and drug resistant malaria. It should be confirmed by microscopy. Amore sensitivemethod holds justice ,when  microscopy and expertise are not available.

Prevalence Of Methicillin Resistant Staphylococcus Aureus Among Healthcare Workers


Methicillin Resistant Staphylococcus aureus (MRSA) nosocomial infection outbreaks and prevalence among various populations are well reported in literature. Nosocomial infection due to MRSA is a known cause of increased hospital stay, morbidity and
mortality especially in the critically ill patients. But there is paucity of information onMRSAin developing countries like India. There is no proper surveillance system and control policy forMRSA.One hundred and fifty healthcare workers were screened for MRSA carrier status and vancomycin susceptibility of the isolates was determined. Swabs of anterior nares were taken, cultured by using nutrient broth with 7.5% NaCl and Mannitol Salt Agar (MSA). Staphylococcus aureus was identified by conventional
biochemical methods. MRSA detection was done by Modified Kirby-Bauer disc diffusion method by using oxacillin (1μg) and  efoxitin (30 μg) discs. Susceptibility to vancomycin was also determined by disc diffusion method using vancomycin (30 μg) disc.Of the 150 healthcare workers screened, 18 had MRSA in the nose giving a carriage rate of 12%. MRSA isolatedwere resistant to commonly available antibiotics. Novancomycin resistancewas detected.MRSA carriage among healthcare workers is high. The isolates were multi-drug resistant which may lead to increased morbidity and mortality if transmitted to the critically ill. There is need forMRSA control policies in the hospitals with normal settings.

paecilomyces variotii, an under diagnosed malady of a microbiologist; causing mycotic infection in the maxillary sinus in an immunocompetent individual. a case report.


Paecilomyces variotii is closely related to Penicillium species.Various studies show that Paecilomyces Spp is encountered most often in the clinical laboratory as contaminants in cultured clinical specimens [1]. Based on the cultural characters and microscopic observations the organism causing the present infection is diagnosed as  Paecilomyces variotii. The fungus can be located anywhere in the body. An initial misdiagnosis in this patient’s case as Penicillium was done which can be attributed to the similarities this fungus shares with Penicillium and that iswhywe refer to it as “Paecilomyces variotii, an under diagnosed malady of a microbiologist; causing mycotic infection in the maxillary sinus in an immunocompetent individual” requiring careful review.

Wrapping up the year 2009-2010 – a collection of rare cases and uncommon etiological agents


The year 2009-2010 gave us fivememorable clinical cases which were rare and two of them had uncommon etiological agents. 1). A female developed a sensation of worms crawling in her mouth and throat, ten days after taking ‘live fish medicine’ given orally for her asthma. An intestinal fluke (Genus Echinostoma) was collected from  her posterior pharyngeal wall. Eggs of the fluke were
detected in her stool. 2). Black lesions developing on the eyelid overnight, ‘ticks’ were the culprits. 3). A small subcutaneous cyst considered as a sebaceous cyst turned out to be a hydatid cyst. 4). Fluid from a hepatic hydatid cyst instead of hydatid sand and protoscolices showed well developed worm with popped up scolex and segments, which is rare. 5). A paralytic disease with
presentation of food – poisoning affecting three members of a family –? Food borne botulism.

A study of prevalence of hepatitis c virus in amalapuram, andhra pradesh


The prevalence of hepatitis C in patients with liver disease is known to be high and several studies have been carried out to evaluate the burden of this disease in society. However, limited data is available as to the prevalence of HCV in general population, particularly in rural areas of India. To assess the prevalence of HCV infection and risk factors involved among the out patients and in patients of Orthopaedics, Gynaecology and Surgery departments of Konaseema Institute of Medical sciences, Amalapuram, India.

Prevalence of extended lactamase producing enterobacteriaceae in a tertiary care centre spectrum


Antimicrobial resistance is an emerging problem in health care settings. One of the common mechanisms of antimicrobial resistance is production of Extended- Spectrum Beta-Lactamase (ESBL) by Gram Negative Bacilli. Knowledge about the prevalence of ESBL producing strains in the local area must be obtained for proper therapeutic interventions in infections caused by them.The purpose of the study was to detect the prevalence of Extended-Spectrum Beta-Lactamase producing Enterobacteriaceae isolates from various infections in a Tertiary Care Hospital, which guides in therapeutic management of such infections.

Hepatic abscess- an unusual presentation of s.typhi


Liver abscess due to S.typhi is an extremely rare occurrence and is associated with high mortality. We describe a 40-year-old female patient with PUO in whom ultrasound revealed a liver abscess and culture of ultrasound guided liver aspirate yielded S.typhi. The Widal testwas positivewith very high titers. No pre-existing liver pathology could be found. Ciprofloxacin therapy resulted in complete recovery.We report the clinical, radiological and microbiological features of this rare condition.