Non O1 non O139 Vibrio cholerae septicemia in a patient with carcinoma pancreas-a case report and literature review, 2020-2023.

Non-O1/non-O139 Vibrio cholerae, a comparably poorly studied pathogen is culpable of sporadic but serious infections. We report a case of non O1 non O139 Vibrio cholerae septicemia in a middle aged male recently diagnosed with carcinoma pancreas. He underwent biliary tract interventional procedure for hematemesis three weeks before the presentation. Now, he presented with fever, abdominal pain, hematemesis and melena. Endoscopy revealed severe portal hypertensive gastropathy and mild hemobilia. Blood culture grew Vibrio cholerae, identified as non O1 non O139 by serogrouping. He recovered successfully with timely diagnosis, appropriate antibiotics and supportive measures.

Burden of biocide resistance among multidrug-resistant bacteria isolated from various clinical specimens in a tertiary care hospital.

BACKGROUND: Most studies on biocide resistance and its genetic determinants arise from environmental or food-borne microbial isolates and only a few from clinically relevant isolates. OBJECTIVES: This study determines the proportion of biocide resistance against five commonly used biocides and detects biocide resistance genes among MDR bacterial isolates using PCR. METHODS: Consecutive MDR isolates (n â€‹= â€‹180) were included (30 each of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Enterococcus species) from clinical specimens of various inpatient units at JIPMER. The isolates were challenged at 0.5,1 and 2 Macfarland (McF) inoculum with discrete dilutions of disinfectants. The minimum bactericidal concentrations (MBCs) for 70% Ethanol, 1.5% Cresol, 2% Glutaraldehyde, 1% Cetrimide, and 1% Chlorhexidine were determined for the isolates using ATCC reference strains as controls. PCR was performed targeting qac A/B, G; smr; and nfx B genes. RESULTS: For all biocides, MDR isolates had MBCs less than the maximum MBCs of ATCC strains. For MDR K. pneumoniae, A. baumannii, and P. aeruginosa, the highest MBCs of chlorhexidine and cetrimide were ≥75 and â€‹≥ â€‹150 â€‹µg/ml respectively at 0.5 McF inoculum; whereas these organisms grew at higher inoculum (2McF) even at commercially recommended biocidal concentration (1%) corresponding to 750 and 1500 â€‹µg/ml of chlorhexidine and cetrimide respectively. Meanwhile, the highest MBCs of MDR E. coli were 75 and 150 â€‹µg/ml for chlorhexidine and cetrimide respectively. Interestingly, the Gram-positive cocci survived the action of up to 35% ethanol. The nfxB and qacG genes were detected in 87% and 6.67% of MDR P. aeruginosa isolates respectively with no biocide resistance genes detected among the other organisms. CONCLUSIONS: Biocide dilutions challenged with higher inoculum indicated a narrow margin of effectiveness for certain biocides. Although a significant proportion of clinical MDR isolates of P. aeruginosa harbored biocide resistance genes, this finding had no phenotypic correlation.

Exploring the use of Congo red agar in improving the serotyping of non-serotypeable Shigella with In-silico evidence.

OBJECTIVES: To assess if congo red could make non-serotypeable Shigella strains serotypeable and to employ molecular docking to determine the basis of the same phenomenon. METHODS: We used 42 bacterial strains of non-serotypeable Shigella collected from 2012 to 2019 for this study. Each bacterial strain was freshly inoculated onto congo red agar and incubated at 37° C for 18-24 h. Bacterial colonies obtained were re-subjected to biochemical tests followed by serotyping and serogrouping. In-silico studies to investigate the interaction between MxiC protein of T3SS and O-antigen LPS with congo red were performed. RESULTS: Of the total 42 non-serotypeable Shigella studied, (26/42)62% were capable of being serotyped following the use of congo red agar, 65% were Shigella flexneri, 19% were Shigella dysenteriae, while 2 strains (7%) each of Shigella boydii and Shigella sonnei were detected. We observed no change in their biochemical properties. The in-silico molecular docking studies revealed high binding affinity between congo red and the B-Chain of Mxi C. Out of the 5 chains of the O-Antigen, congo red showed robust binding with the B-chain with the involvement of a cluster of hydrophobic interactions between them. This may have a crucial role in the conversion of non-serotypeable strains to serotypeable strains on exposure to congo red as observed in our study. CONCLUSION: Congo red agar as a medium converts a sizeable percentage of non-serotypeable Shigella strains to serotypeable Shigella strains.

Bacteriuria due to Typhoidal and Nontyphoidal Salmonella: A Report of Three Cases from South India.

Urinary tract infection (UTI) with Salmonella is uncommon, accounting for merely 0.01% to 0.1% of cases of UTIs. It is reported more frequently in the presence of predisposing factors such as structural abnormalities of the urinary tract or weakened immune system. We present a case series of three patients with Salmonella bacteriuria and their susceptibility patterns. All three patients had underlying urologic features such as neurogenic bladder, chronic kidney disease, and urethral stricture, and two presented with urinary tract involvement symptoms.

CRISPR-cas heterogeneity and plasmid incompatibility types in relation to virulence determinants of Shigella.

Introduction. Virulence factors (VFs) are the most potent weapon in the molecular armoury of Shigella. In bacteria, the mobile genetic elements (MGEs) are contributors to the evolution of different types of clustered regularly interspaced short palindromic repeats-CRISPR associated genes (CRISPR-cas) variants and plasmid incompatibility types. The present study explored the virulence potential of Shigella in relation to the CRISPR-cas pattern and incompatibility types among the isolates.Hypothesis/Gap Statement. The profile of the CRISPR-cas systems among clinical isolates of Shigella in India has not been reported earlier. Limited knowledge is available on the pattern of plasmid incompatibility groups among clinical isolates Shigella. The bias is always towards studying the genetic elements associated with AMR, but the present study highlights CRISPR-cas and incompatibility types among Shigella in association with virulence.Aim. We aimed to investigate the distribution of virulence factors, CRISPR-cas pattern followed by plasmid incompatibility types among Shigella isolates.Methodology. Between 2012-2017, a total of 187 isolates of Shigella were included in the study. The virulence genes' distribution was carried out. CRISPR-cas profiling followed by analysis of the repeats and spacers was carried out. PCR-based replicon typing was used to determine the incompatibility types. The interplay was statistically determined using STATA.Results. The distribution of virulence genes showed varied pattern with ipaH present in all the isolates followed by ompA (93.6 %), virF (66.8 %), ial and sen (60.4 %), set1A (39.6 %) and set1B (39 %). CRISPR 1, CRISPR 3 and Cas6-Cas5 region were dominantly conserved. Twenty-two types of spacers were identified. The CRISPR3 repeat appeared to have a highly conserved sequence. CRISPR2 being the least common CRISPR type showed a strong association with an array of virulence genes (ial-set1A-set1B-virF) while CRISPR1 being the most dominant showed the least association with virulence genes (sen-virF). The dominant plasmids were found to be belonging to the inc FII group. The incompatibility groups FII, IncIγ, U, FIIS, FIIK, K, A/C, I1alpha was found to be associated with a greater number of virulence genes.Conclusion. The isolates showed increasing diversity in their gene content that contributes to increasing heterogeneity among the isolates, which is a known virulence strategy among pathogens.

Azithromycin can induce SOS response and horizontal gene transfer of SXT element in Vibrio cholerae.

BACKGROUND: The emergence and spread of drug resistance in Vibrio cholerae are mainly attributed to horizontal gene transfer of mobile genetic elements, especially the SXT (sulfamethoxazole and trimethoprim) element, an integrative conjugative element carrying multiple drug resistance genes. SOS (save our souls) bacterial stress response in Vibrio cholerae plays a pivotal role in inducing the SXT element transfer and induction of the CTX prophage, carrying the important virulence factor cholera toxin encoded by the ctxAB gene. METHODS: This study investigated whether the subinhibitory concentration of antibiotics like ciprofloxacin, tetracycline, and azithromycin induce SOS response by detecting the expression of recA and lexA, the key genes of SOS response by reverse transcriptase real time PCR (RT-qPCR). We also studied the transfer of SXT element in response to these three antibiotics by bacterial conjugation. Transfer of SXT elements was confirmed by detecting the SXT element-specific conserved genes. RESULTS: The results of the real-time PCR showed that all three antibiotics induced SOS response with more robust induction by tetracycline and azithromycin relative to ciprofloxacin. We observed a higher frequency of transfer of SXT elements in cultures exposed to these antibiotics and the control mitomycin C compared to unexposed cultures. CONCLUSION: Our study indicates that antibiotics including azithromycin, ciprofloxacin, and tetracycline activate SOS response in Vibrio cholerae and demonstrates a robust mechanism for wide dissemination of drug resistance.

Association Between Helicobacter pylori and Periampullary and Pancreatic Cancer: a Case-Control Study.

INTRODUCTION: Helicobacter pylori has been implicated in the etiopathogenesis of various malignant conditions; however, there is a dearth of studies on the correlation between H. pylori infection and pancreatic cancers. Hence, this study was carried out to evaluate the association between H. pylori infection and periampullary and pancreatic cancer. METHODS: This was a single-centre, retrospective, case-control study in which all consecutive patients of periampullary or pancreatic cancer were included. The demographic details with tumour characteristics were recorded. Age and gender-matched controls were patients with other extra-abdominal benign conditions. H. pylori and the Cag A status were determined using IgG antibodies and Cag A antibodies respectively. The association between H. pylori infection and periampullary and pancreatic cancer was the primary outcome. RESULTS: A total of 155 patients, 61 in the study and 94 in the control group were included. The overall prevalence of H. pylori in the study group (78.6%) was similar to that of the control group (76.5%) (p = 0.76). Although a higher trend of IgG and Cag A seropositivity was seen in the study group, the difference was not significant. The correlation of H. pylori and Cag A seropositivity showed a higher trend with site-specificity, differentiation, and nodal status. However, the difference was not significant. CONCLUSION: There was no association between H. pylori infection and Cag A seropositivity with periampullary and pancreatic cancers. The various tumour characteristics were also not associated with H. pylori infection. Thus, routine eradication of H. pylori infection may not be recommended in periampullary and pancreatic cancers.

Surveillance Stool Culture and its Association with Microbiologically Documented Infection During Febrile Neutropenia in Patients with Acute Leukemia (AL) Undergoing Induction Chemotherapy.

The study aimed at identifying the profile of gut colonization of patients with acute leukemia who underwent induction chemotherapy and its association with induction events and outcome. Baseline bacterial stool culture with resistance pattern of isolates were recorded. Multi-drug resistance was defined as resistance to at least two antibiotic classes including beta lactam and fluoroquinolones. During induction chemotherapy, blood and clinically indicated cultures were taken during febrile neutropenic episodes. Association studies were done between gut colonization and induction events/outcome. Among 109 patients enrolled, 71 (65.13%) patients undergoing induction chemotherapy were colonized with bacteria, with nearly 50% of colonizers harboring multi-drug resistant bacteria. Organisms isolated from stool pre-induction were mostly gram negative (98%), with Escherichia coli and Klebsiella pneumoniae being the commonest. 65.13% patients developed febrile neutropenia. Overall multi-drug resistant positivity during febrile neutropenia was 70.14%. Concordance of 8.45% was observed between isolates from stool and organisms isolated from cultures during febrile neutropenia. There were significant proportion of gut colonized gram-negative multi-drug resistance bacteria among patients with acute leukemia. There was a low concordance rate between baseline stool isolates and subsequent cultures during the induction. There was no significant association between gut colonization and induction events/outcomes studied.

Diarrhea and Acute Tubular Necrosis Mimicking Hemolytic Uremic Syndrome in a Man With Immunoglobulin A (IgA) Nephropathy.

Immunoglobulin A (IgA) nephropathy is a heterogeneous disease with variable clinical presentations ranging from asymptomatic hematuria to advanced renal failure. A young male diagnosed with IgA vasculitis (skin, joints, and gastrointestinal) one month ago and placed on oral steroids presented with acute diarrhea, hemolytic anemia, renal failure (non-dialysis requiring), altered sensorium, and thrombocytopenia. The stool was found to be positive for Shiga toxin. He improved with methylprednisolone pulse alone, and renal biopsy showed acute tubular injury.

Asymptomatic bacteriuria among medical inpatients: Data from an Indian teaching hospital.

Studies indicate that asymptomatic bacteriuria in medical inpatients is often inappropriately treated with antibiotics. We prospectively studied the proportion of asymptomatic bacteriuria among 200 positive urine cultures which were ordered in hospitalised medical inpatients of a teaching hospital in southern India. We used pre-defined criteria to classify patients as urinary tract infection and asymptomatic bacteriuria. Median age of patients was 53.5 (42-65) years, and 51% were male. In all, 157 (78.5%) patients had urinary tract infection (131 [66.5%] definite and 26 [13%] probable) and 43 (21.5%) had asymptomatic bacteriuria. In patients with asymptomatic bacteriuria, 18 (41.8%) received urinary tract infection-directed antibiotics; broad spectrum antibiotics were used in 10 (23%). Patients with asymptomatic bacteriuria were younger, more likely to be on a urinary catheter, had higher prevalence of chronic kidney disease and congestive cardiac failure and had lower prevalence of pyuria and lower total leucocyte counts. Urine cultures should be ordered only in indicated patients. Inappropriate antibiotic treatment in patients with asymptomatic bacteriuria should be avoided.

In-vitro study of the effect of Centella asiatica on cholera toxin production and the gene expression level of ctxA gene in Vibrio cholerae isolates.

ETHNOPHARMACOLOGICAL RELEVANCE: Centella asiatica (L.) Urb or Indian pennywort is a plant of ethnopharmacological relevance, commonly called as Brahmi in South India known for its antimicrobial property in gut and for the treatment of other gut ailments. Natural anti-virulence drugs that disarm pathogens by directly targeting virulence factors or the cell viability and are thus preferred over antibiotics as these drugs impose limited selection pressure for resistance development. In this regard, an in-vitro experimental study was conducted to know the effect of extract of Centella asiatica(L.) Urb. on cholera toxin, gene expression and its vibriocidal effect on five standard strains of Vibrio cholerae; IDH03097 (El Tor variant), N16961 (El Tor), O395 (Classical) as well as five clinical strains (Haitian variant). AIM OF THE STUDY: To study the effect of extract of Centella asiatica on Vibrio cholerae. MATERIALS AND METHODS: Crude extract was prepared from the leaves and stem part of the plant. The vibriocidal concentration was tested at different concentrations of the extract. The amount of cholera toxin released from the strains before and after exposure to the extract of Centella asiatica to Vibrio cholerae was measured using Bead ELISA. ctxA gene expression in the strains before and after exposure to extract of Centella asiatica was measured using quantitative real time PCR. All the above assays were performed with commercially obtained asiaticoside as well. RESULTS: The vibriocidal activity was tested at the different concentration of the extract, where 1g/mL of crude extract and 12.5mg/mL of asiaticoside was found to be vibriocidal. The amount of cholera toxin released before and after the exposure to extract of C. asiatica was measured using Bead ELISA, showing a reduction of 70%, 89% and 93% toxin produced by classical, El Tor and variant respectively. ctxA gene expression before and after exposure to extract of Centella asiatica as well as asiaticoside was measured using qRT-PCR. We found a decrease in expression of ctxA gene transcription by 6.19 fold in classical strain, 4.29 fold in El Tor, 1.133 fold in variant strains and about 10.13-10.20 fold for the clinical strains of V. cholerae using the extract of C.asiatica while, the reduction with the exposure to the asiaticoside were 2.762 fold in classical strain, 4.809 in El Tor, 24.1 in variant strain and 34.77 - 34.8 for the clinical strains. CONCLUSION: Centella asiatica extract inhibited the CT production in Vibrio cholerae as well as decreased the transcription of ctxA gene expression.

Clostridioides difficile Diarrhea: An Emerging Problem in a South Indian Tertiary Care Hospital.

Context Clostridioides difficile infection (CDI) is one of the most common infectious causes of hospital-acquired diarrhea. The actual burden of the disease is underestimated in India due to inadequate diagnostic methods and limited studies conducted. Aims The aim of this study was to determine the burden and risk factors of CDI among patients with hospital-acquired diarrhea. Methods and Materials Stool specimen of patients (age > 1 year) with hospital-acquired diarrhea were screened for glutamate dehydrogenase antigen and toxin using an enzyme immunoassay. If both antigen and toxin were present, it was reported as positive for toxigenic CDI. Samples positive for antigen and negative for toxin were further tested with Cepheid GeneXpert assay for detecting the toxin producing gene. Results Of 75 patients (mean age 36.07 ± 20.79, 64% males), 14 (18.67%) patients were positive for toxigenic Clostridioides difficile ( C. difficile ) and 3 (4%) patients were nontoxigenic C. difficile . Addition of GeneXpert to the testing algorithm increased the yield of toxin detection in 5/14 patients who were negative by toxin assay. On analysis of risk factors, prolonged hospital stay was found to have significant association ( p -value = 0.022). Patients with factors like intensive care unit stay, presence of diabetes mellitus as a comorbidity, and exposure to antibiotics like carbapenems and glycopeptides have been found to have a higher prevalence of CDI. Conclusions The prevalence of CDI in our population was 18.67% and the major risk factor associated was prolonged hospital stay. The addition of GeneXpert for the detection of toxin gene increased the yield from 12 to 18.68%.

Diagnostic Accuracy of Point-of-care Nitrite and Leukocyte Esterase Dipstick Test for the Screening of Pediatric Urinary Tract Infections.

Our study aimed to evaluate the diagnostic performance of point-of-care nitrite and leukocyte esterase (LE) dipsticks in the diagnosis of suspected urinary tract infection (UTI) in infants <6 months (young infants) versus older children. The secondary objectives were to study the dipstick efficacy in children with congenital anomalies of the kidney and urinary tract (CAKUT) versus those without CAKUT; in children with simple UTI versus complicated UTI; and to evaluate the clinico-microbiological profile of children presenting with UTI. In this prospective observational study, cases with suspected UTI were enrolled from pediatric emergency or outpatient departments. Urine was collected for performing the urine dipstick and culture. Descriptive data regarding CAKUT, age, gender, etc., were recorded in a predesigned pro forma. We screened 506 children with suspected UTI, of whom 221 had urine culture positive. Approximately 38.4% of the children with UTI had underlying CAKUT, while 7.6% had renal scars. The most common CAKUT was vesicoureteric reflux (VUR). About 12 patients (2.3%) were known to have CAKUT at the time of enrollment in the study. In infants <6 months, LE dipstick had sensitivity 92%, specificity 89.7%, positive predictive value (PPV) 86.7%, negative predictive value (NPV) 93.8%, likelihood ratio (LR) + 8.9, LR- 0.09. In infants <6 months, nitrite dipstick had sensitivity 38%, specificity 97%, PPV 90.4%, NPV 68%, LR+ 12.6 and LR-0.63. In the age group 6 months to 12 years, the efficacy was better for both dipsticks. In age group more than 6 months to 12 years, LE dipstick had sensitivity 96.4%, specificity 95.8%, PPV 94.8 %, NPV 97.2%, LR+ 22.9, LR- 0.04. In age group more than six months to 12 years, nitrite dipstick had sensitivity 94.7%, specificity 99.5%, PPV 99.3%, NPV 96%, LR+ 189.4, and LR-0.05.

Evaluation of LAMP for detection of Shigella from stool samples in children.

BACKGROUND: To assess the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for the detection of Shigella from stool samples from children. METHODS: Consecutive stool samples from children aged <13 years old who presented with acute watery diarrhoea or dysentery to the Department of Paediatrics were collected and processed in the Department of Microbiology. All the stool samples were subjected to culture, conventional PCR and LAMP. Genomic sequencing was performed for samples that were positive by LAMP but negative by both culture and conventional PCR. The LAMP results were compared to those from culture and to a composite reference standard based on culture and conventional PCR. RESULTS: Amongst the 374 stool samples tested, 291 samples were positive by LAMP and 213 were positive by the composite reference standard. The sensitivity of LAMP was 100 % (98.3-100 %) and its specificity was 51.6 % (43.6-59.5 %) with a disease prevalence of 57 %. The sensitivity and specificity of LAMP improved to 99.3 % (94.2-100) and 98.2 % (94.5-99.9), respectively, using latent class analysis, while assuming that genomic sequencing has perfect specificity. DISCUSSION: The authors have standardized the LAMP procedure for direct application to clinical stool samples. LAMP is a sensitive and specific method for the diagnosis of Shigella from stool samples of children as compared to both culture and conventional PCR.

Reevaluating the true diagnostic accuracy of dipstick tests to diagnose urinary tract infection using Bayesian latent class analysis.

OBJECTIVE: Previous studies on diagnostic accuracy of dipstick testing for leukocyte esterase (LE) and nitrite to diagnose urinary tract infection (UTI) had used urine culture, which is an imperfect gold standard. Estimates of diagnostic accuracy obtained using the classical gold standard framework might not reflect the true diagnostic accuracy of dipstick tests. METHODS: We used the dataset from a prospective, observational study conducted in the emergency department of a teaching hospital in southern India. Patients with a clinical suspicion of UTI underwent dipstick testing for LE and nitrite, urine microscopy, and urine culture. Based on the results of urine microscopy and culture, UTI was classified into definite, probable, and possible. Patients with microscopic pyuria and a positive urine culture were adjudicated as definite UTI. Unequivocal imaging evidence of emphysematous pyelonephritis or perinephric collections was also considered definite UTI. We estimated the diagnostic accuracy of LE and nitrite tests using the classical analysis (assuming definite UTI as gold standard) and two different Bayesian latent class models (LCMs; 3-tests in 1-population and 2-tests in 2-populations models). RESULTS: We studied 149 patients. Overall, 64 (43%) patients had definite, 76 (51%) had probable, and 2 (1.3%) had possible UTI; 7 (4.6%) had alternate diagnoses. In classical analysis, LE was more sensitive than nitrite (87.5% versus 70.5%), while nitrite was more specific (24% versus 58%). The 3-tests in 1-population Bayesian LCM indicated a substantially better sensitivity and specificity for LE (98.1% and 47.6%) and nitrite (88.2% and 97.7%). True sensitivity and specificity of urine culture as estimated by the model was 48.7% and 73.0%. Estimates of the 2-tests in 2-populations model were in agreement with the 3-tests in 1-population model. CONCLUSIONS: Bayesian LCMs indicate a clinically important improvement in the true diagnostic accuracy of urine dipstick testing for LE and nitrite. Given this, a negative dipstick LE would rule-out UTI, while a positive dipstick nitrite would rule-in UTI in our study setting. True diagnostic accuracy of urine dipstick testing for UTI in various practice settings needs reevaluation using Bayesian LCMs.

Use of fosfomycin combination therapy to treat multidrug-resistant urinary tract infection among paediatric surgical patients - a tertiary care centre experience.

With increasing resistance to currently used antibiotics, antibiotic combinations are being resorted to. The present study deals with five children with complicated urinary tract infection (UTI) whose urine cultures grew multidrug-resistant (MDR) organisms. In all of these five cases, MDR organisms were the causative agents for UTI and the currently available antibiotics, including colistin, were ineffective, although the organisms were sensitive in vitro. In all of these cases, the isolates reverted to being susceptible to the quinolones and cephalosporins tested, namely ceftriaxone and ceftazidime. All were treated using a combination of fosfomycin with other antibiotics, since it has no interference with other classes of antibiotics. Our observations suggest that the use of a combination of fosfomycin with either a carbapenem or an aminoglycoside in a clinical setting would be a reasonable choice to treat UTIs caused by MDR organisms, especially in complicated cases that require chronic therapy.

Impact of Therapeutic Drug Monitoring on Once-Daily Regimen of Amikacin in Patients With Urinary Tract Infection: A Prospective Observational Study.

BACKGROUND: Amikacin is a semisynthetic antibiotic used in the treatment of gram-negative bacterial infections and has a narrow therapeutic index. Although therapeutic drug monitoring is recommended for amikacin, it is not routinely performed because of the use of a less toxic once-daily regimen. Only few studies have evaluated the role of therapeutic drug monitoring in patients treated with amikacin. The objective of our study was to find an association between the pharmacokinetic parameters of amikacin and the time required for a clinical cure, creatinine clearance, and frequency of ototoxicity in patients with urinary tract infection treated for 7 or more days. METHODS: A prospective study was conducted on patients with urinary tract infections who were administered amikacin for 7 or more days. Blood samples were obtained from the patients to measure the maximum drug concentration (Cmax) and trough concentration (Ctrough). Minimum inhibitory concentration (MIC) values were determined for patients with positive urine cultures. Serum creatinine levels were estimated every 3 days. The auditory assessment was performed using pure tone audiometry at baseline and weekly until the patients were discharged. Levels of amikacin were analyzed using a validated liquid chromatography-tandem mass spectrometry method. RESULTS: Of 125 patients analyzed, the median time required for a clinical cure was less in the group of patients who achieved a Cmax/MIC ratio ≥8 than it was in those who did not achieve this level [7 versus 8 days (P = 0.02)]. The Ctrough of amikacin was associated with the change in serum creatinine level (P = 0.01) and the incidence of nephrotoxicity (P = 0.004). CONCLUSIONS: In patients receiving short-term amikacin therapy, Cmax/MIC value can be used to predict the time required for a clinical cure. Ctrough can be used to predict the occurrence of nephrotoxicity in patients receiving amikacin therapy.

Haitian-like genetic traits with creeping MIC of Azithromycin in Vibrio cholerae O1 isolates from Puducherry, India.

Introduction. The emergence of novel strains of Vibrio cholerae O1 El Tor biotype has gained attention due to causing several epidemics around the world. Variant strains have evolved as a result of the acquisition of genes that confer extended virulence and pathogenicity.Aim. This study aimed to determine the presence of the most recently emerging Haitian-like genetic traits among the isolates from Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, Southern India. We also wanted to detect the prevalence of the sulfamethoxazole and trimethoprim (SXT) element, which is an integrating conjugative element (ICE) and the antimicrobial resistance genes present in our isolates.Methodology. Identification of Haitian-specific alleles was done by mismatched amplification mutation assay PCR (MAMA-PCR). The presence of SXT elements was carried out by PCR by detecting int, eex, att-prfC and setR genes. Detection of antibiotic resistance determinant, sul(1,2,3); dfr(A1,18,5) for trimethoprim resistance, tet(A,B,C,D,E,Y,G,M), tet34 for tetracycline resistance and erm(A,B,C), mph(A,B), ere(A,B), msr(A,D) for azithromycin resistance were targeted by PCR. The MIC of tetracycline, ciprofloxacin and azithromycin was determined by the E-test method.Results. Of the 95 isolates, 60 % of the isolates were found to carry Haitian-specific alleles of ctxB, tcpA and rtxA gene, 100 % of the isolates were found to carry SXT elements. All the isolates harboured the four conserved genes of the SXT element, except one which had only eex, att-prfC, setR genes. About 99 % harboured sul2 and dfrA1 genes. No tet and macrolide genes were detected. We observed a progressive increase in the MIC of azithromycin ranging from 0.75 µg ml-1 to 2 µg ml-1.Conclusion. None of the isolates were the prototype El Tor biotype. All the isolates were a Haitian variant. The presence of SXT elements across all our isolates and their creeping MIC of azithromycin is a matter of concern. Further testing for other genetic determinants of resistance will be carried out in our future studies.

An in vitro experimental study of the effect of fosfomycin in combination with amikacin, ciprofloxacin or meropenem on biofilm formation by multidrug-resistant urinary isolates of Escherichia coli.

Background. This study was conducted to understand the effect of fosfomycin in combination with amikacin, ciprofloxacin or meropenem on biofilm formation by multidrug-resistant urinary isolates of Escherichia coli.Methods. Fifty urinary tract multidrug-resistant E. coli isolates that were known biofilm producers were studied. The MIC was determined using the agar dilution method for amikacin, ciprofloxacin, meropenem and fosfomycin. The fractional inhibitory concentration was determined for the combination of antibiotics followed by a time-kill assay. A tissue culture plate method was used to study the effect of the combination of antibiotics on biofilm formation.Results. The MICs of the isolates tested ranged from 0.25 to 32 µg ml-1 for fosfomycin, 1 to 1024 µg ml-1 for ciprofloxacin, 4 to 1024 µg ml-1 for amikacin, and 0.25 to 512 µg ml-1 for meropenem. The combination of fosfomycin with meropenem showed 68 % synergy, fosfomycin with amikacin 58 % synergy and fosfomycin with ciprofloxacin 6 % synergy. The combination also reduced the MIC of each antibiotic and none showed an antagonistic effect. Biofilm inhibition was best observed with the combination of fosfomycin with meropenem.Conclusion. The combination of fosfomycin with amikacin and fosfomycin with meropenem yielded a high percentage of synergy alongside an increased capacity to reduce biofilm formation when compared to combination with ciprofloxacin against multidrug-resistant E. coli. Fosfomycin in combination with other classes of antimicrobial agents has potential beneficial effects.