Time to positivity of blood cultures causing candidemia and its relation to mortality.

Background and Objectives: Early diagnosis of candidemia is of vital importance in reducing mortality and morbidity. The main objective of the study was to determine the TTP (Time to Positivity) of different species of Candida causing bloodstream infection and to see whether TTP can help differentiate Candida glabrata which is frequently fluconazole resistant from Fluconazole sensitive Candida. Materials and Methods: TTP (Time to positivity) and AAT (Appropriate Antifungal therapy) were noted for Blood cultures becoming positive for Candida. Presence of Risk factors for candidemia like prolonged ICU stay, neutropenia, Total Parenteral Nutrition (TPN), use of steroids , broad spectrum antibiotics, use of Central Venous Catheter, Foleys catheter were also analyzed. Results: The most frequent isolates were Candida parapsilosis, Candida tropicalis and Candida albicans. The median TTP for all Candida isolates in our study was 34 hours. The diagnostic sensitivity of TTP for detecting C. glabrata and C. tropicalis in patients with candidemia was 88% and 85% respectively. TTP showed that there was no difference in survival between TTP <24 hrs. and > 24hrs. Initiation of antifungal therapy <24 hours and > 24hrs after onset of candidemia had no association with survival. Conclusion: Longer TTP maybe predictive of C. glabrata while shorter TTP may be predictive of C. tropicalis. In our study we found that fluconazole resistant Candida causing blood stream infection is quite unlikely if the TTP of the isolate is <48hrs.

Prevalence and antimicrobial susceptibility pattern of Salmonella and Shigella in stool among patients presenting with diarrhea in a tertiary care centre in South India.

Background and Objectives: Bacterial causes of gastroenteritis include Salmonella, Shigella spp, diarrheagenic Escherichia coli, Vibrio cholera and Campylobacter spp. Although infections caused by NTS (Non Typhoidal Salmonella) and Shigella are usually self-limiting, antibiotic treatment is prefered in severely ill or immunocompromised individuals. The main objective of the study was to find out the prevalence of Salmonella and Shigella among the stool samples received in Believers Church Medical College hospital and the antimicrobial susceptibility pattern of Salmonella spp. and Shigella spp. Materials and Methods: A total of 805 stool samples collected from cases of diarrhea from January 2018 to December 2021 were processed in the laboratory. Standard bacteriological methods were used to isolate, identify, and determine the antimicrobial susceptibility pattern of Salmonella and Shigella isolates using the disc diffusion method and interpreted according to CLSI. Results: A total of 100 (12.4%) samples yielded bacterial pathogens. Salmonella was isolated from 97 (12%) samples and Shigella from 3 (0.4%) samples. Salmonella enterica serovar Typhimurium was the predominant serotype, accounting for 53 (54.6%) isolates. Conclusion: This study showed Salmonella enterica serovar Typhimurium as the predominant isolate causing diarrheal illness. The emergence of multidrug resistant phenotypes warrants the continuous monitoring of susceptibility trend of NTS in India.

Ceftaroline Susceptibility among Isolates of MRSA: A Comparison of EUCAST and CLSI Breakpoints.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important bacterial pathogen causing a number of community-acquired and nosocomial infections. Ceftaroline fosamil is a fifth generation cephalosporin, approved for the treatment of infections caused by MRSA. The main objective of this study was to estimate the susceptibility of ceftaroline among isolates of MRSA by using CLSI and EUCAST breakpoints. Materials and Methods: Fifty non-duplicate isolates of MRSA were included in the study. Ceftaroline susceptibility was done using E-strip test and interpreted using CLSI and EUCAST breakpoints. Results: Susceptible isolates were equal (42%) by both CLSI and EUCAST, while resistant isolates were more commonly seen in EUCAST (50%). Ceftaroline MIC ranged from 0.25- >32µg/ml. All the isolates were sensitive to Teicoplanin and Linezolid. Conclusions: Resistant isolates were less (30%) while using the CLSI 2021 criteria probably due to the inclusion of SDD category. Our study showed that Fourteen isolates (28%) had Ceftaroline MIC >32µg/ml, which is an alarming finding. The high percentage of Ceftaroline resistant isolates in our study probably suggest a hospital spread of Ceftaroline resistant MRSA emphasizing the need for stringent infection control precautions.

Cryptococcal antigen prevalence in HIV patients from a tertiary care centre in South India.

Background and Objectives: Cryptococcosis is an opportunistic mycosis, caused by Cryptococcus neoformans. Cryptococcal meningitis is one of the most fatal opportunistic infections associated with human immunodeficiency virus (HIV) infection. The aim of this study was to find the prevalence of cryptococcal antigenemia in people living with HIV (PLHA) and also to find the prevalence of opportunistic infections among these patients. Materials and Methods: A total of 204 non duplicate samples were collected from people with HIV aged above 18 years. Samples with CD4 count less than 300 were included in the study. Cryptococcal antigen detection was done by CrAg Lateral flow assay. Results: None of the patients in our study were positive for cryptococcal antigen. Opportunistic infections were observed in 82 (40.2%) HIV positive patients. Candidiasis, tuberculosis and Pneumocystis jiroveci pneumonia were the most common opportunistic infections. Conclusion: This is the first study from the southern state of Kerala on the prevalence of Cryptococcal antigenemia among HIV positive individuals. The study showed that routine screening for cryptococcal antigen will not be cost effective in our population. Similar to other studies, eventhough candidiasis, tuberculosis and PCP were more commonly seen among people with CD4 count < 200 cells/mm3, there was no statistically significant association.

COVID-19 Vaccines Portray the Bright Side of Human Creativity, But It Means Nothing until They Prove Their Worth: A Study on Seroconversion after the first Dose of Covishield Vaccine in Central Kerala.

Background: COVID-19 vaccines, we believe, have come to rescue us from the clutches of the dreaded severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With rapid ongoing mutations, it is difficult to predict the effectiveness of seroconversion following vaccination. This study aims to find out the proportion of people with seroconversion following first dose of Covishield vaccine. Methods: Randomly selected health-care workers were followed up for SARS-CoV-2 immunoglobulin G (IgG) antibodies between 28 and 42 days after receiving their first vaccine dose. The VITROS SARS-CoV-2 IgG test (Ortho-Clinical Diagnostics, USA) with 100% specificity and > 90% sensitivity was used to assess seroconversion. Results: The first dose of vaccine induced seroconversion in 91.7% of beneficiaries. Nearly one-third (30.2%) of them had high antibody titers, and it showed a significant association with female gender (9.6 ± 5.5 vs. 7.6 ± 5.6) and younger age (P = 0.008). In addition, those with previous COVID infection showed a more robust immune response when compared to others (P = 0.001). Conclusion: Seroconversion rate of more than 90% offers a promising hope toward successful pandemic control. In the current scenario, the inability to attain the targeted coverage due to an upsurge in vaccine hesitancy, compounded with only lower proportion of seroconversion in elderly, faster rollout of the vaccines without any age limit, will help achieve the herd threshold more rapidly.

Ventriculoperitoneal shunt infection by Cryptococcus neoformans sensu stricto: Case report and literature review.

BACKGROUND: Cryptococcal ventriculoperitoneal shunt infection is known to occur due to an underlying infection in the patient rather than by nosocomial transmission of Cryptococcus during shunt placement. A case of chronic hydrocephalus due to cryptococcal meningitis that was misdiagnosed as tuberculous meningitis is described. CASE REPORT: Patient details were extracted from charts and laboratory records. The identification of the isolate was confirmed by PCR-restriction fragment length polymorphism of the orotodine monophosphate pyrophosphorylase (URA5) gene. Antifungal susceptibility was determined using the CLSI M27-A3 broth microdilution method. Besides, a Medline search was performed to review all cases of Cryptococcus ventriculoperitoneal shunt infection. Cryptococcus neoformans sensu stricto (formerly Cryptococcus neoformans var. grubii), mating-type MATα was isolated from the cerebrospinal fluid and external ventricular drain tip. The isolate showed low minimum inhibitory concentrations for voriconazole (0.06mg/l), fluconazole (8mg/l), isavuconazole (<0.015mg/l), posaconazole (<0.03mg/l), amphotericin B (<0.06mg/l) and 5-fluorocytosine (1mg/l). The patient was treated with intravenous amphotericin B deoxycholate, but died of cardiopulmonary arrest on the fifteenth postoperative day. CONCLUSIONS: This report underlines the need to rule out a Cryptococcus infection in those cases of chronic meningitis with hydrocephalus.

Ventriculoperitoneal shunt infection by Cryptococcus neoformans sensu stricto: Case report and literature review

BackgroundCryptococcal ventriculoperitoneal shunt infection is known to occur due to an underlying infection in the patient rather than by nosocomial transmission of Cryptococcus during shunt placement. A case of chronic hydrocephalus due to cryptococcal meningitis that was misdiagnosed as tuberculous meningitis is described.Case reportPatient details were extracted from charts and laboratory records. The identification of the isolate was confirmed by PCR-restriction fragment length polymorphism of the orotodine monophosphate pyrophosphorylase (URA5) gene. Antifungal susceptibility was determined using the CLSI M27-A3 broth microdilution method. Besides, a Medline search was performed to review all cases of Cryptococcus ventriculoperitoneal shunt infection. Cryptococcus neoformans sensu stricto (formerly Cryptococcus neoformans var. grubii), mating-type MATα was isolated from the cerebrospinal fluid and external ventricular drain tip. The isolate showed low minimum inhibitory concentrations for voriconazole (0.06mg/l), fluconazole (8mg/l), isavuconazole (<0.015mg/l), posaconazole (<0.03mg/l), amphotericin B (<0.06mg/l) and 5-fluorocytosine (1mg/l). The patient was treated with intravenous amphotericin B deoxycholate, but died of cardiopulmonary arrest on the fifteenth postoperative day.ConclusionsThis report underlines the need to rule out a Cryptococcus infection in those cases of chronic meningitis with hydrocephalus. (AU)

AntecedentesLa infección criptocócica por contaminación de las derivaciones ventriculoperitoneales es una complicación que puede tener lugar en el paciente previamente infectado más que deberse a una transmisión nosocomial de Cryptococcus durante la colocación del dispositivo. Se describe un caso de hidrocefalia crónica por meningitis criptocócica que se diagnosticó erróneamente como meningitis tuberculosa.Caso clínicoLos datos del paciente se extrajeron de la historia clínica y de los registros de laboratorio. La identificación del aislamiento se confirmó mediante PCR de polimorfismo de longitud de fragmento de restricción del gen de la orotodina monofosfato pirofosforilasa (URA5). La sensibilidad a los antifúngicos se realizó mediante el método de microdilución en caldo CLSI M27-A3. Se realizó, además, una búsqueda en Medline para revisar todos los casos de infección por Cryptococcus asociados a derivación ventriculoperitoneal. Se aisló Cryptococcus neoformans sensu stricto (antes Cryptococcus neoformans var. grubii), tipo MATα, del líquido cefalorraquídeo y de la punta del drenaje extraventricular. El aislamiento mostró, in vitro, valores bajos de concentración mínima inhibitoria para el voriconazol (0,06mg/l), el fluconazol (8mg/l), el isavuconazol (<0,015mg/l), el posaconazol (<0,03mg/l), la anfotericina B (<0,06mg/l) y la 5-fluorocitocina (1mg/l). El paciente fue tratado con anfotericina B desoxicolato intravenoso, pero falleció por parada cardiopulmonar el decimoquinto día del postoperatorio.ConclusionesNuestro caso subraya la necesidad de descartar la presencia de Cryptococcus en los casos de meningitis crónica con hidrocefalia. (AU)

Evaluation of chromogenic agar medium, can it be a suitable alternative to conventional culture system for identification of uropathogens?

Background and Objectives: Urinary tract infections (UTI) account for major proportion of outpatient load and hospital admission globally. In most of the clinical microbiology laboratories MacConkey agar (MAC) and Cystine lactose electrolyte-deficient (CLED) agar are being used for identification of uropathogens. The main objective of the present study was to evaluate the usefulness of HiCromeTM UTI by comparing isolation rate and presumptive identification of uropathogens against CLED and MAC agar. Materials and Methods: This study was conducted over a period of three months on 672 non-duplicate midstream and/or catheter-catch urine samples. All samples were inoculated on to HiCromeTM UTI, CLED agar and MacConkey agar. Results: Among the 672 samples received for culture, 113 (16.8%) showed significant growth. Among the 672 samples, 95 (14.1%) showed growth of a single organism while 18 (2.7%) showed polymicrobial growth. The rate of isolation and presumptive identification of the isolates and polymicrobial growth was found significantly higher on HiCromeTM UTI Agar. Conclusion: HiCromeTM UTI Agar has the potential to streamline processing of samples for urine culture in a way that will reduce the workload for technicians, reduce turnaround time which in turn will benefit the laboratory ultimately leading to better patient care.

Prevalence of Anti-HBc Antibodies among HBsAg Negative Individuals and Its Association with Occult Hepatitis B.

Introduction Hepatitis B virus (HBV) infection is an endemic in many Asian countries, and among the major routes of transmission, transfusion is the one that should be prevented. Occult HBV infection (OBI) is defined as the presence of HBV DNA in the absence of detectable HBsAg, with or without anti-HBV antibodies. The aim of this study was to detect the prevalence of anti-HBc total antibodies among the HB surface antigen (HBsAg) negative individuals by way of enzyme-linked immunosorbent assay (ELISA), and detect the presence of HBV DNA among the anti-HBc seropositives by polymerase chain reaction (PCR). Anti-HBs among the HBV DNA positives were also found out by enzyme-linked fluorescent assay (ELFA). Materials and Methods A total of 910 serum samples was subjected to initial screening for HBsAg by MERILISA HBsAg ELISA kits. The anti-HB core (HBc) total antibody titer was evaluated using MONOLISA ELISA (Biorad) kits. If found negative, the samples were discarded. If found positive, the samples underwent HBV DNA testing by nested PCR. Antibody to hepatitis B surface antigen (anti-HBs) was calculated among the DNA positives by ELFA. Results A total of 133 samples were positive for anti-HBC total antibody, resulting in an overall prevalence of 14.6%. Overall prevalence of HBV DNA among the anti-HBc seropositives was 2.2%. Conclusion Among the three HBV DNA positive patients, two belonged to the preoperative screening group, which is an alarming situation. Screening of blood for HBsAg has reduced the incidence of posttransfusion hepatitis, but HBV still remains the major source of transfusion transmitted infection in India.

Comparison of PCR and phenotypic methods for the detection of methicillin resistant Staphylococcus aureus.

BACKGROUND AND OBJECTIVES: Resistance to methicillin in methicillin resistant strains of Staphylococcus aureus (MRSA) is due to the presence of mec-A gene, which encodes a low affinity penicillin binding protein (PBP)-2a or PBP2. Accurate and rapid identification of MRSA in clinical specimens is essential for timely decision on effective treatment. The aim of the study was to compare three different methods for detection of MRSA namely cefoxitin disc diffusion, CHROM agar MRSA and VITEK-2 susceptibility with PCR which is the gold standard reference method and to find the antibiotic susceptibility pattern of these isolates by VITEK-2. MATERIALS AND METHODS: A Total of 100 non-duplicate S. aureus isolates were collected from different clinical samples among both outpatient and inpatients. Detection of MRSA among these isolates was done by cefoxitin disc diffusion, VITEK-2, CHROM agar MRSA and PCR. RESULTS: The sensitivity and specificity of cefoxitin disc diffusion and Vitek was found to be 97.2% and 100%, while that of CHROM agar was found to be 100% and 78.6%. The overall prevalence of MRSA in our study by PCR was 72%. CONCLUSION: Based on the findings in our study, isolates which show cefoxitin zone diameter < 22 mm can be reported as MRSA. However, those isolates which have a zone diameter between 22-24 mm, should ideally be confirmed by PCR.

Evaluation of Matrix-assisted laser desorption/ionization Time-of flight Mass spectrometry (MALDI TOF MS) and VITEK 2 in routine microbial identification.

Bacground: Microbial Identification was done by phenotypic methods. VITEK-2 and Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) are now being increasingly used in laboratories. Objectives: To compare and evaluate the usefulness of MALDI-TOF MS and VITEK-2 in routine microbial identification. Methods: The performances of MALDI-TOF MS and VITEK 2 were compared for identifying microorganisms. Results: MALDI- TOF MS and VITEK-2 correctly identified 96 % (96/100) and 97% (97/100) of the isolates upto the genus level. Conclusion: MALDI TOF MS and VITEK -2 gave comparable identification and error rates. The rapid reduction in turnaround time with MALDI TOF is a significant game-changer in the field of clinical microbiology. Funding: State Board of Medical Research (SBMR).

Non O1/ O139 Vibrio Cholerae Septicemia in a Patient with Hepatocellular Carcinoma.

BACKGROUND: An elderly male with underlying Hepatocellular carcinoma came with history of fall with head and ear trauma, vomiting, abdominal pain, fatigue. Patient died within hours due to Septic shock Blood culture grew Non O1/O139 Vibrio cholerae which was later found to be non-toxigenic. This was a lethal case of non-O1/non-O139 V. cholerae sepsis and we focus on the dilemmas in identification and management of this rare bacterium.

Chromobacterium violaceum causing deadly sepsis.

Infections caused by Chromobacterium violaceum are extremely rare but can be relatively fatal in septicemia. We report a case of a 76 year old female who presented with pustules in the skin and later developed into septicemia. She succumbed to the illness despite escalating the antibiotic therapy to meropenem. To the best of our knowledge this is the 16th case report from India.

Prevalence of hepatitis C among haemodialysis patients in a tertiary care hospital in south India.

BACKGROUND AND OBJECTIVES: Hepatitis C is the most common hepatotropic viral infection that affects patients on maintenance hemodialysis. Most of the laboratories in India depend on HCV antibody detection by ELISA. PCR based studies on detection of HCV RNA among haemodialysis patients are very scanty in India. The current study was undertaken to find the prevalence of HCV among haemodialysis patients by ELISA and PCR. MATERIALS AND METHODS: This prospective study was conducted from January to May 2018 in a total of 100 samples. Patients more than 18 years of age, who had undergone at least 15 sessions of dialysis were enrolled in the study. All samples were screened for HCV antibody by ELISA and HCV RNA by PCR. Data regarding age and gender of the patients, history of blood transfusion, duration of hemodialysis, total bilirubin levels were collected from medical records. RESULTS: Among the 100 samples, only one was positive for HCV antibody by ELISA. Eight samples were positive for HCV RNA by PCR. In this study 62.5% of the HCV positives had a previous history of blood transfusion. Duration of dialysis was more among the HCV positive group but there was no statistical significance. CONCLUSION: This is the first study from the southern state of Kerala in India showing the prevalence of HCV among hemodialysis patients by PCR. Our study showed an overall HCV prevalence of 8% by PCR. All the PCR positive samples were negative by 3rd generation ELISA which is an alarming finding and further justifies the need for PCR for detecting HCV.

Prevalence of dengue and leptospirosis co-infection in a tertiary care hospital in south India.

BACKGROUND AND OBJECTIVES: Dengue and Leptospirosis were often discussed separately with rash being more common in dengue and jaundice in leptospirosis. But with increasing reports of co-infection, the situation has become worse. The main objective of this study was to look for the presence of both Dengue and Leptospira IgM antibodies in serum samples of patients, presenting with acute febrile illness. Medical records of the co-infected patients were examined to analyse the clinical features and laboratory findings. MATERIALS AND METHODS: Serum samples of patients presenting with acute febrile illness were screened for the presence of Dengue IgM antibodies and Leptospira antibodies. Clinical features and laboratory parameters of patients with co-infection were compared with patients having dengue alone. Rainfall data was obtained to look for an association between rainfall and Dengue, leptospirosis and co-infected cases. RESULTS: Co-infection was seen in 33 (3.4%) samples. There was a statistically significant association between clinical features like rashes, bleeding gums and co-infection. There was a statistically significant association between various laboratory parameters like thrombocytopenia and co-infection. There was positive correlation between rainfall and development of dengue, leptospirosis, and co-infection but it was not statistically significant. CONCLUSION: The overall prevalence of co-infection was 3.4%. This study re-emphasizes the fact that dengue and leptospirosis are widely prevalent in south India and clinicians should be aware that co-infection with dengue and leptospirosis is not uncommon.

A prospective cross sectional study of detection of Clostridium difficile toxin in patients with antibiotic associated diarrhoea.

BACKGROUND AND OBJECTIVES: Clostridium difficile infections (CDI) include self-limiting antibiotic associated diarrhoea (AAD), antibiotic-associated colitis, and pseudomembranous colitis. The present study aimed at detecting C. difficile toxin in stool samples of patients with AAD and analyzing the antibiotic use and presence of other risk factors in these patients. MATERIALS AND METHODS: In this study, which was conducted on 660 samples, a 2- step strategy was used. In the first step, glutamate dehydrogenase (GDH) was detected in stool samples by enzyme-linked immunofluorescent assay (ELFA). In the second step, GDH positive samples were tested for C. difficile toxin A and B by ELFA. Nucleic acid amplification test (NAAT) was also performed on few samples that were found to be GDH positive and toxin negative or equivocal by ELFA. RESULTS: Of the 660 samples screened, toxin was detected in 8.8% (58/660) by ELFA and 9.7% (64/660) by NAAT. GDH was detected in 23.8% (157/660) and toxin in 36.9% (58/157) of the GDH positives. Most of the toxin positive patients were on one or more antibiotics prior to developing diarrhoea. The implicated antibiotics were meropenem, amikacin, colistin and cephalosporins. Diabetes, hypertension, use of proton pump inhibitors, previous hospitalization, malignancy and chemotherapy were found to be the risk factors in our study. CONCLUSION: Prevalence of GDH was 23.8% (157/660) by ELFA. Toxin prevalence was 9.7% (64/660). Detection rates of C. difficile associated diarrhoea (CDAD) increased with inclusion of NAAT testing by ELFA.

Simple low cost differentiation of Candida auris from Candida haemulonii complex using CHROMagar Candida medium supplemented with Pal's medium / Diferenciación sencilla y de bajo coste de Candida auris del complejo Candida haemulonii con el empleo del medio CHROMagar Candida enriquecido con medio de Pal

Background. Candida auris is unique due to its multidrug resistance and misidentification as Candida haemulonii by commercial systems. Its correct identification is important to avoid inappropriate treatments. Aims. To develop a cheap method for differentiating C. auris from isolates identified as C. haemulonii by VITEK2. Methods. Fifteen C. auris isolates, six isolates each of C. haemulonii and Candida duobushaemulonii, and one isolate of Candida haemulonii var. vulnera were tested using CHROMagar Candida medium supplemented with Pal's agar for better differentiation. Results. On CHROMagar Candida medium supplemented with Pal's agar all C. auris strains showed confluent growth of white to cream colored smooth colonies at 37°C and 42°C after 24 and 48h incubation and did not produce pseudohyphae. The isolates of the C. haemulonii complex, on the contrary, showed poor growth of smooth, light-pink colonies at 24h while at 48h the growth was semiconfluent with the production of pseudohyphae. C. haemulonii complex failed to grow at 42°C. Conclusions. We report a rapid and cheap method using CHROMagar Candida medium supplemented with Pal's agar for differentiating C. auris from isolates identified as C. haemulonii by VITEK2 (AU)

Antecedentes. Candida auris es una especie única debido a su resistencia a múltiples fármacos y a la identificación errónea por sistemas comerciales como Candida haemulonii. Su correcta identificación es importante para evitar un tratamiento inadecuado. Objetivos. Desarrollar un método de bajo coste para diferenciar C. auris de aislamientos identificados como C. haemulonii por el método VITEK®2. Métodos. Quince aislamientos de C. auris, seis de C. haemulonii, seis aislamientos de Candida duobushaemulonii y un aislamiento de Candida haemulonii var. vulnera se sembraron en medio CHROMagar Candida enriquecido con medio de Pal para una mejor diferenciación. Resultados. En el medio CHROMagar Candida enriquecido con medio de Pal, todos los aislamientos de C. auris presentaron un crecimiento confluente con colonias lisas de color blanco a blanco amarillento a 37 y 42°C tras 24 y 48 h de incubación; no hubo producción de seudohifas. Los aislamientos del complejo C. haemulonii, en cambio, mostraron un crecimiento menor. Las colonias eran lisas y de un color rosa claro a las 24 h; a las 48 h el crecimiento fue semiconfluente y se observó producción de seudohifas. No hubo crecimiento de ninguno de los aislamientos a 42°C. Conclusiones. El medio CHROMagar Candida enriquecido con medio de Pal es rápido y de bajo coste, y resulta efectivo para identificar C. auris entre cepas previamente identificadas como C. haemulonii por el método VITEK®2 (AU)

Simple low cost differentiation of Candida auris from Candida haemulonii complex using CHROMagar Candida medium supplemented with Pal's medium.

BACKGROUND: Candida auris is unique due to its multidrug resistance and misidentification as Candida haemulonii by commercial systems. Its correct identification is important to avoid inappropriate treatments. AIMS: To develop a cheap method for differentiating C. auris from isolates identified as C. haemulonii by VITEK2. METHODS: Fifteen C. auris isolates, six isolates each of C. haemulonii and Candida duobushaemulonii, and one isolate of Candida haemulonii var. vulnera were tested using CHROMagar Candida medium supplemented with Pal's agar for better differentiation. RESULTS: On CHROMagar Candida medium supplemented with Pal's agar all C. auris strains showed confluent growth of white to cream colored smooth colonies at 37°C and 42°C after 24 and 48h incubation and did not produce pseudohyphae. The isolates of the C. haemulonii complex, on the contrary, showed poor growth of smooth, light-pink colonies at 24h while at 48h the growth was semiconfluent with the production of pseudohyphae. C. haemulonii complex failed to grow at 42°C. CONCLUSIONS: We report a rapid and cheap method using CHROMagar Candida medium supplemented with Pal's agar for differentiating C. auris from isolates identified as C. haemulonii by VITEK2.

Antimicrobial activity of plumbagin, a naturally occurring naphthoquinone from Plumbago rosea, against Staphylococcus aureus and Candida albicans.

Candida albicans and Staphylococcus aureus are opportunistic pathogens. Despite causing a number of independent infections, both pathogens can co-infect to cause urinary tract infections, skin infections, biofilm associated infections, sepsis and pneumonia. Infections of these two pathogens especially their biofilm associated infections are often difficult to treat using currently available anti-bacterial and anti-fungal agents. In order to identify a common anti-microbial agent which could confer a broad range of protection against their infections, we screened several phytochemicals and identified plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), a phytochemical from Plumbago species as a potent antimicrobial agent against S. aureus and C. albicans, with a minimum inhibitory concentration of 5µg/ml. Antimicrobial activity of plumbagin was validated using an ex-vivo porcine skin model. For better understanding of the antimicrobial activity of plumbagin, a Drosophila melanogaster infection model was used, where D. melanogaster was infected using S. aureus and C. albicans, or with both organisms. The fly's survival rate was dramatically increased when infected flies were treated using plumbagin. Further, plumbagin was effective in preventing and dispersing catheter associated biofilms formed by these pathogens. The overall results of this work provides evidence that plumbagin, possesses an excellent antimicrobial activity which should be explored further for the treatment of S. aureus and C. albicans infections.