Anaerobic Profile of Intra-abdominal Infections – A 23-Year Retrospective Study

Obligate anaerobes, which are part of normal intestinal flora are now gaining pathogenic potential by becoming more virulent and causing moderate to severe abdominal infections. Moreover, there is delay in initiation of appropriate antimicrobial therapy. The study aimed to describe and analyse 23 years data on anaerobic intra – abdominal infections in regards to the distribution and antimicrobial susceptibility patterns of the obligate anaerobes which were isolated from various intra – abdominal infections. The demographic and microbiological data was retrieved from the microbiology departmental registers. Total number of cases/specimen were 1124. Bacteroides fragilis group (238) (56%) and Peptostreptococcus sp (109) (25%) amounted to the majority of the isolates. Rare anaerobes like Clostridium sporogenes, Propionibacterium sp, Clostridium bifermentans and Fusobacterium varium were also isolated. Majority of mixed anaerobic infections were contributed by Bacteroides fragilis group and Peptostreptococcus sp (99) out of 102 mixed anaerobic infections). Chronic alcoholism was the most common predisposing condition (p value <0.05). Among the antimicrobials which were used by the clinicians for treating the infection, only Metronidazole was tested for its susceptibility pattern. One isolate was resistant to metronidazole (Diameter of inhibition zone was 6 mm). As they are fastidious they usually go unnoticed. Hence, this descriptive study intends to bring light on the large number of various obligate anaerobes and the potential diseases that they can cause and also the need for their antibiotic susceptibility testing to look for antimicrobial resistance among the isolates

INCIDENCE OF MYCOTIC INFECTIONS IN DIABETIC FOOT TISSUE

The objective of the study was to investigate the incidence of fungal pathogens in diabetic foot infections. A total of 74 Type II diabetic patients with non-healing diabetic foot infections were recruited for the study. Among the diabetic patients 65 % (48/74) had yeast and mold infections. Pathogenic yeasts were noted in 77 % of the patients of which Candida species was predominant (93 %). The major Candida species isolated were C. albicans (49 %), C. tropicalis (23 %), C. parapsilosis (18 %), C. guillermondi (5 %) and C. krusei (5 %). The other yeast species isolated were Trichosporon cutaneum and T. capitatum. Trichophyton spp. was the only dermatophytic fungus found. Molds were isolated from 38 % of the infected patients of which Aspergillus species predominated (72 %). The other molds isolated were Fusarium solani, Penicillium marneffei and Basidiobolus ranarum. The results of the study indicate the need for mycological evaluation of the non-healing diabetic foot tissues and appropriate antifungal therapy

Streptomyces pneumonia in an immunocompetent adult — a rare isolate

Streptomyces belongs to the Actinomycetes group of bacteria which are gram-positive non acid-fast bacilli, widely recognised for their potential to produce antimicrobials active against bacterial, mycobacterial, parasitic and fungal infections. They commonly cause cutaneous infections following traumatic inoculation. Visceral infections are relatively rare and limited to immunocompro-mised hosts. We describe a case of Streptomyces pneumonia in a healthy immunocompetent female, who when investigated for voluntary kidney donation, resulted in the isolation of Streptomyces species from bronchial wash cultures. Streptomyces, a potential pathogen in immunocompetent hosts is frequently underdiagnosed. Once isolated, both physicians and microbiologists should pay attention to differentiate true infection from contamination

Ventilator-Associated Pneumonia

Background Ventilator-associated pneumonia (VAP) is the most frequent infection in patients intubated for longer than 48 hours. There is a great interest in determining the factors influencing the outcome of VAP, as it may help in reducing the associated morbidity and mortality. This study aimed to determine the impact of appropriate antibiotic therapy based on endotracheal aspirate cultures on the outcome of VAP. We have also studied the other factors that may influence the outcome of VAP. Method  A cohort study was conducted in the intensive care units of a tertiary care hospital in South India over a period of 15 months. The outcome of VAP was assessed by prolongation of the duration of mechanical ventilation and/ or death of the patient. Results The duration of mechanical ventilation was significantly prolonged in patients with VAP (16.61 ± 8.2 d vs. 8.21 ± 5.9 d, P 2 days in administering the first dose of appropriate antibiotic therapy significantly prolonged the duration of ventilation (P < 0.0001). Infection by multi-drug resistant pathogens, polymicrobial infection and time of onset of VAP did not have significant impact on the outcome of VAP. Conclusion Early administration of appropriate antibiotic therapy, based on the antibiogram of the VAP pathogens identified by quantitative culture of endotracheal aspirate, could lead to an improved outcome of patients with ventilator-associated pneumonia

Arcanobacterium haemolyticum associated with pyothorax: case report

Arcanobacterium haemolyticum has an established role in the etiology of human pharyngitis. There are increasing reports of systemic infections caused by this organism. From India, we report the first case of Arcanobacterium haemolyticum causing pyothorax in an immunocompetent adolescent male patient. The probable mode of infection is also discussed. The role of A. hemolyticum as an animal pathogen needs further study

Global patterns in monthly activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus: a systematic analysis

Background: Influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus are the most common viruses associated with acute lower respiratory infections in young children (<5 years) and older people (≥65 years). A global report of the monthly activity of these viruses is needed to inform public health strategies and programmes for their control. Methods: In this systematic analysis, we compiled data from a systematic literature review of studies published between Jan 1, 2000, and Dec 31, 2017; online datasets; and unpublished research data. Studies were eligible for inclusion if they reported laboratory-confirmed incidence data of human infection of influenza virus, respiratory syncytial virus, parainfluenza virus, or metapneumovirus, or a combination of these, for at least 12 consecutive months (or 52 weeks equivalent); stable testing practice throughout all years reported; virus results among residents in well-defined geographical locations; and aggregated virus results at least on a monthly basis. Data were extracted through a three-stage process, from which we calculated monthly annual average percentage (AAP) as the relative strength of virus activity. We defined duration of epidemics as the minimum number of months to account for 75% of annual positive samples, with each component month defined as an epidemic month. Furthermore, we modelled monthly AAP of influenza virus and respiratory syncytial virus using site-specific temperature and relative humidity for the prediction of local average epidemic months. We also predicted global epidemic months of influenza virus and respiratory syncytial virus on a 5° by 5° grid. The systematic review in this study is registered with PROSPERO, number CRD42018091628. Findings: We initally identified 37 335 eligible studies. Of 21 065 studies remaining after exclusion of duplicates, 1081 full-text articles were assessed for eligibility, of which 185 were identified as eligible. We included 246 sites for influenza virus, 183 sites for respiratory syncytial virus, 83 sites for parainfluenza virus, and 65 sites for metapneumovirus. Influenza virus had clear seasonal epidemics in winter months in most temperate sites but timing of epidemics was more variable and less seasonal with decreasing distance from the equator. Unlike influenza virus, respiratory syncytial virus had clear seasonal epidemics in both temperate and tropical regions, starting in late summer months in the tropics of each hemisphere, reaching most temperate sites in winter months. In most temperate sites, influenza virus epidemics occurred later than respiratory syncytial virus (by 0·3 months [95% CI −0·3 to 0·9]) while no clear temporal order was observed in the tropics. Parainfluenza virus epidemics were found mostly in spring and early summer months in each hemisphere. Metapneumovirus epidemics occurred in late winter and spring in most temperate sites but the timing of epidemics was more diverse in the tropics. Influenza virus epidemics had shorter duration (3·8 months [3·6 to 4·0]) in temperate sites and longer duration (5·2 months [4·9 to 5·5]) in the tropics. Duration of epidemics was similar across all sites for respiratory syncytial virus (4·6 months [4·3 to 4·8]), as it was for metapneumovirus (4·8 months [4·4 to 5·1]). By comparison, parainfluenza virus had longer duration of epidemics (6·3 months [6·0 to 6·7]). Our model had good predictability in the average epidemic months of influenza virus in temperate regions and respiratory syncytial virus in both temperate and tropical regions. Through leave-one-out cross validation, the overall prediction error in the onset of epidemics was within 1 month (influenza virus −0·2 months [−0·6 to 0·1]; respiratory syncytial virus 0·1 months [−0·2 to 0·4]). Interpretation: This study is the first to provide global representations of month-by-month activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus. Our model is helpful in predicting the local onset month of influenza virus and respiratory syncytial virus epidemics. The seasonality information has important implications for health services planning, the timing of respiratory syncytial virus passive prophylaxis, and the strategy of influenza virus and future respiratory syncytial virus vaccination. Funding: European Union Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe (RESCEU)

Evaluation of colorimetric nitrate reductase assay for rapid detection of methicillin resistance in clinical isolates of Staphylococcus aureus

Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) remains a major cause of health care-associated infections. Rapid detection of MRSA facilitates the early initiation of appropriate treatment and infection control. Hence, the present study was undertaken to standardize and evaluate the performance of rapid colorimetric nitrate reductase assay (NRA) for determining methicillin resistance in S.aureus. Methods: A total of 160 clinical isolates of S. aureus, (80 each of methicillin susceptible and methicillin resistant) were included in the study. Minimum inhibitory concentration (MIC) was determined by NRA and reference broth micro dilution (BMD) methods. Results of NRA were compared with BMD and analyzed. Results: For MRSA, the MIC values ranged from 4 to ≥ 16 μg/ml and for MSSA, ≤ 0.5 to 2 μg/ml. Category and essential agreement for NRA as compared with BMD were found to be 99.4 and 89.7 per cent, respectively. No minor or major discrepancy was observed. A single resistant isolate showed very major discrepancy. Interpretation & conclusions: Colorimetric NRA being an inexpensive test requiring no special equipment can be employed as an alternative method for rapid detection of MRSA in resource limited settings

Worrisome trends in rising minimum inhibitory concentration values of antibiotics against methicillin resistant Staphylococcus aureus - Insights from a tertiary care center, South India

ABSTRACT INTRODUCTION: Appearance of isolated reports of resistance to anti-methicillin-resistantStaphylococcus aureus (MRSA) drugs is worrisome underscoring the need to continuously monitor the susceptibility of clinical MRSA isolates to these drugs. Hence, the present study is conducted to determine the susceptibility of MRSA isolates to various classes of anti-MRSA drugs such as vancomycin (glycopeptide), daptomycin (lipopeptide), tigecycline (glycylcycline), and linezolid (oxazolidinone) to determine the MIC50 and MIC90 values, and to observe MIC creep over a three year period, if any, with respect to these drugs. METHODS: A total of 200 isolates of MRSA obtained from clinical specimens were included. MIC was determined by E-test for anti-MRSA antibiotics vancomycin, linezolid, daptomycin, and tigecycline. Non-parametric methods (Kruskal-Wallis and Chi-square test) were used to assess MIC trends over time. In addition, MIC50 and MIC90 values were also calculated. RESULTS: No isolate was found resistant to vancomycin, daptomycin, or linezolid; five isolates were resistant to tigecycline. Seven VISA isolates were encountered with the MIC value for vancomycin of 4 µg/mL. MIC values for vancomycin, tigecycline, linezolid showed a definite increase over a 3-year period which was statistically significant with p-values <0.0001, 0.0032, 0.0242, respectively. When the percentage of isolates with a median MIC value less than or equal to that of the index year was calculated, the change was most striking with vancomycin. The proportion of isolates with higher MIC values was greater in 2014 than 2012 and 2013. CONCLUSION: MIC creep was notably observed with vancomycin, and to some extent with tigecycline and linezolid. Selection pressure may result in creeping MICs, which may herald the emergence of resistant organisms