Predominant Bacterial Pathogens Research Articles

Bacterial Susceptibility to Antibiotics in Urinary Tract Infections in Children, KSAFH, Saudi Arabia, Tabuk

Objective: this study aimed to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from patients with community-acquired urinary tract infections (UTIs) at King Salman Armed Forces Hospital, Saudi Arabia, Tabuk. Urinary tract infections (UTIs) remain the common infections diagnosed in outpatients as well as hospitalized patients. Early diagnosis and comprehensive treatment can significantly decrease late serious complications. Current knowledge on antimicrobial susceptibility pattern is essential for appropriate therapy. Methods: urinary isolates from symptomatic UTI cases attending to King Salman Armed Forces Hospital were identified by conventional methods. Positive urine cultures from 210 patients aged less than 14 years were studied. Antimicrobial susceptibility testing was performed by Kirby Bauer's disc diffusion method. Results were analyzed by using the NCCLS guidelines of the 210 samples that showed growth of pathogens. Results: the most prevalent were E. coli (96.7%) followed by Klebsiella spp (3.3%). The majority (81%) of the isolates were from females, while the remaining was from males. Among these gram-negative enteric bacilli very high prevalence of resistance was observed against Ampicillin and Co-trimoxazole. For E.coli the lowest resistant rate was that for Nitrofurantoin 10.3% followed by Norfloxacin and Ceftriaxone (11.3% and 11.8% respectively). Resistance to Gentamicin and Nalidixic acid was observed in 19.2% and 47.3% respectively. For Klebsiella, all organisms were sensitive to Gentamicin and Norfloxacin and all organisms were resistant to Ampicillin. There was a high resistance rate to Ceftriaxone (42.9%).Conclusion: this study revealed that E. coli was the predominant bacterial pathogen of community-acquired UTIs at King Salman Armed Forces Hospital. Most of the organisms were resistant to Ampicillin and Co-trimoxazole; it also demonstrated an increased resistance to Nalidixic acid and Gentamicin. This study is useful for the clinician in order to improve the empiric treatment.

Bacterial Susceptibility to Antibiotics in Urinary Tract Infections in Children, KSAFH, Saudi Arabia, Tabuk

Objective: this study aimed to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from patients with community-acquired urinary tract infections (UTIs) at King Salman Armed Forces Hospital, Saudi Arabia, Tabuk. Urinary tract infections (UTIs) remain the common infections diagnosed in outpatients as well as hospitalized patients. Early diagnosis and comprehensive treatment can significantly decrease late serious complications. Current knowledge on antimicrobial susceptibility pattern is essential for appropriate therapy. Methods: urinary isolates from symptomatic UTI cases attending to King Salman Armed Forces Hospital were identified by conventional methods. Positive urine cultures from 210 patients aged less than 14 years were studied. Antimicrobial susceptibility testing was performed by Kirby Bauer's disc diffusion method. Results were analyzed by using the NCCLS guidelines of the 210 samples that showed growth of pathogens. Results: the most prevalent were E. coli (96.7%) followed by Klebsiella spp (3.3%). The majority (81%) of the isolates were from females, while the remaining was from males. Among these gram-negative enteric bacilli very high prevalence of resistance was observed against Ampicillin and Co-trimoxazole. For E.coli the lowest resistant rate was that for Nitrofurantoin 10.3% followed by Norfloxacin and Ceftriaxone (11.3% and 11.8% respectively). Resistance to Gentamicin and Nalidixic acid was observed in 19.2% and 47.3% respectively. For Klebsiella, all organisms were sensitive to Gentamicin and Norfloxacin and all organisms were resistant to Ampicillin. There was a high resistance rate to Ceftriaxone (42.9%).Conclusion: this study revealed that E. coli was the predominant bacterial pathogen of community-acquired UTIs at King Salman Armed Forces Hospital. Most of the organisms were resistant to Ampicillin and Co-trimoxazole; it also demonstrated an increased resistance to Nalidixic acid and Gentamicin. This study is useful for the clinician in order to improve the empiric treatment.

FilmArray® meningitis/encephalitis (ME) panel, a rapid molecular platform for diagnosis of CNS infections in a tertiary care hospital in North India: one-and-half-year review.

Acute meningitis and encephalitis (AME) is a syndrome of central nervous system (CNS) infections, which could lead to neurological damage and fatality. This study evaluates the multiplex FilmArray® ME Panel which is aimed to diagnose agents causing suspect CNS infections in north India. A total number of 969 cerebrospinal fluid (CSF) samples collected between August 2016 and January 2018 from patients who showed clinical symptoms of CNS infections were analyzed using the FilmArray® ME Panel. Also a comparison of molecular diagnosis and various laboratory and radiological findings for Streptococcus pneumoniae, Enterovirus and Cryptococcus neoformans positive cases was done. Out of the 969 CSF samples, 101 cases were found to be positive for viral (n= 55), bacterial (n= 38), fungal (n= 7), and poly-microbial (n= 1) agents. Out of the 55 viral positive cases, the most detected pathogen was Enterovirus (n= 23) with predominance in the age group of 2-17years, followed by Varicella Zoster virus (n= 14) and HSV1(n= 9) cases. Streptococcus pneumoniae (n= 26) was found to be the predominant bacterial pathogen, of which 17 were detected in the age group above 35years. Cryptococcus neoformans was found in 7 cases. The FilmArray® ME Panel aids in rapid detection of 14 pathogens directly from CSF. When compared to gram stain, culture, antigen detection, and CSF biochemical analysis, the FilmArray® ME Panel has detected more cases, some of which are difficult to diagnose by conventional methods. This rapid technology will help the clinicians in case of early patient management, outcomes and provide aid in antimicrobial stewardship.

Multi-level analysis of bacteria isolated from inpatients in respiratory departments in China.

With the different situation for clinical antibiotic usage and its management in different regions and medical institutions, the antimicrobial resistance varied in different level. However, the epidemiological data of multi-drug resistant (MDR) strains from the department of respiration is limited. Thus, this study aims to investigate the epidemiology of bacteria isolated from inpatients of respiratory departments, and analyze the distribution variation of major multi-drug resistant bacteria in China. Based on data from China Antimicrobial Resistance Surveillance System (CARSS) in 2015, 50,417 non-duplicate isolates obtained from inpatients of respiratory departments from 91 general hospitals in seven regions of China were enrolled in the study. The distribution of methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Escherichia coli (CREC) and Klebsiella pneumoniae (CRKP), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and Acinetobacter baumannii (CRAB), extended-spectrum β-lactamases-producing E. coli (ESBL-EC) and K. pneumoniae (ESBL-KP), were further analyzed by geographic regions, age groups, wards and specimen types. The major specimens type were sputum (81.6%, 41,131/50,417), followed by blood (5.3%, 2,649/50,417), urine (4.5%, 2,249/50,417) and bronchoalveolar lavage fluid (BALF) (3.2%, 1,620/50,417). The top four bacteria species isolated from sputum and BALF were similar: K. pneumonia (18.9% and 14.8%, respectively), P. aeruginosa (13.6% and 22.2%, respectively), A. baumannii (11.3% and 11.9%, respectively) and S. pneumonia (11.1% and 9.6%, respectively). The four most common bacteria species were K. pneumonia (17.2%), P. aeruginosa (12.1%), A. baumannii (10.4%) and S. pneumonia (10.1%) in tertiary hospitals but K. pneumonia (20.8%), P. aeruginosa (16.3%), E. coli (11.3%) and A. baumannii (6.9%) in secondary hospitals. The top four bacteria species in respiratory intensive care unit (RICU) were A. baumannii (25.8%), P. aeruginosa (13.1%), K. pneumonia (12.2%) and S. aureus (9.2%). The prevalence of CRKP, CRPA and CRAB in tertiary hospitals was significantly higher than that in secondary hospitals (5.2% vs. 2.5%, 23.8% vs. 12.8% and 53.5% vs. 33.9%, respectively) (all P<0.05). However, the prevalence of ESBL-EC in secondary hospitals was higher than in tertiary ones (63.9% vs. 55.0%, P=0.011). The prevalence of MRSA, CRKP, CRAB, CRPA, ESBL-EC, ESBL-KP in RICU were higher than that in non-ICU respiratory departments (76.5% vs. 35.7%, 20.1% vs. 4.1%, 90.6% vs. 45.5%, 64.2% vs. 19.3%, 47.2% vs. 28.3% and 43.0% vs. 11.2%, respectively) (all P<0.01). Among seven regions in China, central area had the highest detection rates of MRSA (70.3%, 237/337), CRPA (30.9%, 376/1,218), CRAB (71.8%, 487/678) and ESBL-KP (38.8%, 241/621). The prevalence of ESBL-EC and ESBL-KP in pediatric group (68.2% and 55.3%, respectively) was higher than that in geriatric group (54.2% and 27.1%, respectively) and adult group (51.1% and 15.1%, respectively) (all P<0.001). In China, the predominant bacterial pathogens in the respiratory ward were Enterobacteriaceae and non-fermentative bacteria. High prevalence of ESBL-EC and ESBL-KP isolated from lower respiratory tract (LRT) was revealed in primary hospitals and pediatric patients.

The composition and antimicrobial resistance of isolates from lower respiratory tract and blood in hospitalized patients in respiratory ward: a multicenter national study in China

Objective: To investigate the species and antimicrobial resistance of bacterial pathogens isolated from hospitalized patients in respiratory ward in China. Methods: This was a multicenter retrospective study based on a national epidemiological network called China Antimicrobial Resistance Surveillance System (CARSS). The non-repetitive strains isolated from lower respiratory tract and blood samples in 91 hospitals from seven geographic regions of CARSS were reviewed. The distribution of specimen type, hospital level (secondary and tertiary hospital), patient age group [geriatric (>65 years old), adult (15 to 65 years old), pediatric (28 days to 14 years old ) and newborn group (≤28 days)] and ward type (respiratory intensive care unit and general respiratory ward) were analyzed for MRSA, PRSP, CREC, CRKP, CRPA, CRAB, ESBL-EC and ESBL-KP. The categorical variables were analyzed by chi-square test using SPSS 16.0 statistical software. P<0.05 was regarded as statistically significant. Results: A total of 50 417 non-repetitive isolates [42 751 isolates from lower respiratory tract (LRT), 2 649 isolates from blood and 5 017 isolates from other samples (urine and secretions)] from 48 752 inpatients (without illness type information) were enrolled in the study. 90.2% (45 491/50 417) isolates were obtained from 63 tertiary hospitals. According to patients' age, all cases were divided into 4 groups, i. e. geriatric(46.0%, 23 177/50 417), adult(29.9%, 15 092/50 417), pediatric(24.0%, 12 112/50 417) and newborn group(0.0%, 36/50 417). All isolates were obtained from respiratory intensive care unit (6.2%, 3 129/50 417) or general respiratory wards (93.8%, 47 288/50 417). The majority of bacterial pathogens were isolated from lower respiratory and blood culture samples, which accounted for 90.0% of all the samples (45 400/50 417). Sputum accounted for 81.6% (41 131/50 417) of samples, and the leading 4 isolates were K. pneumonia (18.9%, 7 784/41 131), P. aeruginosa (13.6%, 5 580/41 131), A. baumanni (11.3%, 4 644/41 131) and S. pneumonia (11.1%, 4 564/41 131). Blood samples accounted for 5.3% (2 649/50 417) of the samples, with the leading 4 bacteria being coagulase-negative staphylococcus (42.0%, 1 112/2 649), E. coli (18.3%, 484/2 649), K. pneumonia (7.4%, 194/2 649) and S. aureus (4.9%, 131/2 649). The species distribution of pathogens isolated from bronchoalveolar lavage fluid (BALF), which accounted for 3.2% (1 620/50 417) of the samples, was similar to that of sputum, and the leading 4 bacteria were P. aeruginosa (22.0%, 360/1 620), K. pneumonia (14.8%, 239/1 620), A. baumanni (11.9%, 193/1 620) and S. pneumonia (9.6%, 155/1 620). The prevalence of CRKP, CRPA and CRAB in tertiary hospitals [5.2% (384/7 439), 23.8% (1 260/5 304) and 53.5% (2 259/4 224), respectively] was significantly higher than that in secondary hospitals [2.5% (24/973), 12.8% (101/787) and 33.9% (109/322), respectively] (all P<0.01). In comparison, the prevalence of ESBL-EC in secondary hospitals (63.9%, 145/227) was higher than that in tertiary ones (55.0%, 1 141/2 074) (P=0.011). The prevalence of ESBL-EC and ESBL-KP in pediatric group [68.2% (283/415) and 55.3% (183/331), respectively] was higher than that in geriatric group [54.2% (684/1 263) and 27.1% (625/2 303), respectively] and adult group [51.1% (317/620) and 15.1% (272/1 804), respectively] (all P<0.001). Conclusions: In China, the predominant bacterial pathogens in the respiratory wards were Enterobacteriaceae and non-fermentative bacteria. High prevalence of ESBL-EC and ESBL-KP isolated from lower repiratory tract was revealed in primary hospitals and pediatric patients.

Antibiogram of bacterial agents of lower respiratory tract infections in a central Nigerian hospital

BACKGROUND: Lower respiratory tract infections (LRTIs) are one of the major public health concerns in Nigeria. They are associated with significant morbidity and mortality in children and adults.AIM: To identify bacterial causative agents of lower respiratory tract infections and to determine their antibiotic susceptibility profile to locally available antibiotics.METHODS: This was a retrospective study conducted at National Hospital Abuja (NHA). Laboratory data of processed sputum samples of patients with suspected lower respiratory tract infection at National Hospital Abuja were extracted, reviewed and analyzed from 1st January 2016- 1st December 2016. RESULT: Out of the six hundred and thirteen cases, 89 (14.5%) had an established bacterial cause. The prevalence of LRTIs was higher in males (56.1%) than females. Age group 21-40 (25.8%) had the highest cases of LRTIs followed by those aged 41- 60 (20.2%). Klebsiellapneumoniae (52.8%) was the most predominant isolates, followed by Pseudomonas aeruginosa (15.7%), Staphylococcus aureus (13.5%), Escherichia coli (7.9%), Enterococcus spp (5.6%) and Proteus spp (4.5%). The predominant bacterial pathogens were generally highly susceptible to fluoroquinolones, aminoglycosides and carbapenems.CONCLUSION: Klebsiellapneumoniae was the most common bacterial causative agent of LRTIs in Abuja. Fluroquinolones, aminoglycosides and carbapenemsare antibiotics of good choice for empiric management of this infection in this locality. Regular monitoring of trends of this aetiologic agent and its antimicrobial susceptibility profile is important in effective management of these infections.KEY WORDS: Antibiogram, Bacterial Isolates, LRTIs, National Hospital Abuja, Nigeria

Bacterial Aetiology and Antibiotic Resistance Pattern of Community-Acquired Urinary Tract Infections in Children in a Tertiary Care Hospital in Bangladesh

Background: Urinary tract infections (UTIs) in children are among the most common bacterial infections. Community-acquired urinary tract infections (CAUTI) are often treated empirically with broad-spectrum antibiotics. Pattern of aetiologic agents and their antibiotic sensitivity may vary according to geographical and regional location. So, knowledge of antibiotic resistance trends is important for improving evidence-based recommendations for empirical treatment of UTIs.Objectives: To determine the common bacterial aetiologies of CAUTIs and their antibiotic resistance patterns in a tertiary care hospital, Savar.Materials and Methods: This cross-sectional descriptive study was conducted at Enam Medical College Hospital, Savar from May 2016 to April 2017. We collected clean-catch mid-stream urine samples from 257 patients having clinical diagnosis of UTI and submitted to the clinical microbiology laboratory for culture and sensitivity.Results: A total of 120 (46.7%) samples were positive for bacterial growth. Escherichia coli (79%) was the most common pathogen, followed by Klebsiella spp. (14%). Bacterial isolates showed high prevalence of resistance to multiple antibiotics. Resistance against amoxicillin/clavulanic acid, co-trimoxazole and ciprofloxacin was higher compared to newer quinolones and aminoglycosides.Conclusion: Esch. coli and Klebsiella spp. were the predominant bacterial pathogens. The resistance pattern to commonly prescribed antibiotics was quite high and alarming.J Enam Med Col 2017; 7(3): 134-139

The Proteome of Biologically Active Membrane Vesicles from Piscirickettsia salmonis LF-89 Type Strain Identifies Plasmid-Encoded Putative Toxins.

Piscirickettsia salmonis is the predominant bacterial pathogen affecting the Chilean salmonid industry. This bacterium is the etiological agent of piscirickettsiosis, a significant fish disease. Membrane vesicles (MVs) released by P. salmonis deliver several virulence factors to host cells. To improve on existing knowledge for the pathogenicity-associated functions of P. salmonis MVs, we studied the proteome of purified MVs from the P. salmonis LF-89 type strain using multidimensional protein identification technology. Initially, the cytotoxicity of different MV concentration purified from P. salmonis LF-89 was confirmed in an in vivo adult zebrafish infection model. The cumulative mortality of zebrafish injected with MVs showed a dose-dependent pattern. Analyses identified 452 proteins of different subcellular origins; most of them were associated with the cytoplasmic compartment and were mainly related to key functions for pathogen survival. Interestingly, previously unidentified putative virulence-related proteins were identified in P. salmonis MVs, such as outer membrane porin F and hemolysin. Additionally, five amino acid sequences corresponding to the Bordetella pertussis toxin subunit 1 and two amino acid sequences corresponding to the heat-labile enterotoxin alpha chain of Escherichia coli were located in the P. salmonis MV proteome. Curiously, these putative toxins were located in a plasmid region of P. salmonis LF-89. Based on the identified proteins, we propose that the protein composition of P. salmonis LF-89 MVs could reflect total protein characteristics of this P. salmonis type strain.

Characterization of (Uropathogenic) E. coli isolated from urinary tract infections: phylogenetic typing and distribution of virulence-associated traits

Uropathogenic Escherichia coli (UPEC) is the pre-dominant bacterial pathogen causing Urinary Tract infections (UTIs). Pathogenicity of UPEC results from presence and expression of several virulence...

Phenotypic and Molecular Resistance Pattern of E. Coli Isolated from School Children with Asymptomatic Bacteriuria

Background: Asymptomatic bacteriuria can develop systematic UTI, and considered as an omen sign for the presence of urinary tract abnormalities. Community transmission of ESβL and carbapenemases producing multidrug resistant E. coli has increased progressively and considered important public health problem. Objectives: This study was carried out during the period of January 2016 to January to2017 involving 1200 school children to determine the prevalence of ASB and antibiotic resistance pattern of urinary E. coli isolated from asymptomatic school children. Methodology: Urine analysis and culture with bacterial counting was done for detection of ASB. Antibiogram was done for E. coli that caused ASB by disk diffusion method with special regards to colistin and tigycycline. Phenotypic identification of ESβLs production was confirmed by the combined disk synergy test (CD-T) and analysed regarding to PCR results which detected SHV, TEM and CTX-M ESβL genes. Phenotypic identification of carbapenemase production with confirmatory (IPM/EDTA-CD) test was done. Results: Out of 1200 asymptomatic school chidren, 160(13.3%) had bacteriuria where 67(5.6%) had significant bacterial count. ASB was more prevalent in the age group of >12y(7.7%) and female children(8.8%). E. coli was the predominant bacterial pathogen causing ASB, 46/1200(3.8%). that represented 46/67(68.7%) of ASB children. and were sensitive to colistin and tigycycline by disc diffusion method. 43.5% of them by confirmatory (CD-T), and 47.8% by PCR were ESβL- producing. Percentage of ESβL genes among them(46) was as follow, 30.4%, 19.6% and 10.8% for SHV, TEM and CTX-M genes respectively. Also (16/46)34.8% were carbapenemase positive by screening disc diffusion test, (13/46)28.3% were (MβL) positive by confirmatory IPM/EDTA-CD test. Conclusion: ASB was significantly higher in age group >12 y and in female children. E. coli was the most prominent bacterial isolate. Multi-drug resistant E. coli producing ESβL or carbapenemases among ASB school children need adequate concern

Modeling the Potential for Vaccination to Diminish the Burden of Invasive Non-typhoidal Salmonella Disease in Young Children in Mali, West Africa.

BackgroundIn sub-Saharan Africa, systematic surveillance of young children with suspected invasive bacterial disease (e.g., septicemia, meningitis) has revealed non-typhoidal Salmonella (NTS) to be a major pathogen exhibiting high case fatality (~20%). Where infant vaccination against Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae has been introduced to prevent invasive disease caused by these pathogens, as in Bamako, Mali, their burden has decreased markedly. In parallel, NTS has become the predominant invasive bacterial pathogen in children aged <5 years. While NTS is believed to be acquired orally via contaminated food/water, epidemiologic studies have failed to identify the reservoir of infection or vehicles of transmission. This has precluded targeting food chain interventions to diminish disease transmission but conversely has fostered the development of vaccines to prevent invasive NTS (iNTS) disease. We developed a mathematical model to estimate the potential impact of NTS vaccination programs in Bamako.Methodology/Principal FindingsA Markov chain transmission model was developed utilizing age-specific Bamako demographic data and hospital surveillance data for iNTS disease in children aged <5 years and assuming vaccine coverage and efficacy similar to the existing, successfully implemented, Hib vaccine. Annual iNTS hospitalizations and deaths in children <5 years, with and without a Salmonella Enteritidis/Salmonella Typhimurium vaccine, were the model’s outcomes of interest. Per the model, high coverage/high efficacy iNTS vaccination programs would drastically diminish iNTS disease except among infants age <8 weeks.Conclusions/SignificanceThe public health impact of NTS vaccination shifts as disease burden, vaccine coverage, and serovar distribution vary. Our model shows that implementing an iNTS vaccine through an analogous strategy to the Hib vaccination program in Bamako would markedly reduce cases and deaths due to iNTS among the pediatric population. The model can be adjusted for use elsewhere in Africa where NTS epidemiologic patterns, serovar prevalence, and immunization schedules differ from Bamako.

Acute exacerbations of chronic obstructive pulmonary disease: etiological bacterial pathogens and antibiotic resistance in Upper Egypt

Previous data on etiologic bacteria in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) in Upper Egypt are limited. The aim of this study was to identify the causative bacteria in AECOPD and to determine the antibiotic resistance patterns for AECOPD in Upper Egypt. The study design was a prospective one and was conducted in a University Hospital. Patients who were admitted in Assiut University Hospital with AECOPD were prospectively enrolled. Sputum specimens were investigated using culture. Susceptibilities of the isolated bacterial strains to different antibiotics were determined using the disk diffusion method. During 18 months, 156 patients who experienced 218 AECOPD were enrolled. A significant bacterial growth was found in 77% of patients during 81% of exacerbations. The most commonly detected bacteria were Haemophilus influenzae (18%), Streptococcus pneumoniae (15%), and Klebsiella pneumoniae (14%). The majority of the isolated strains showed high resistance rates to most groups of antibiotics; 63% of the isolated strains were multidrug resistant, 29% were extensively drug resistant, and 5% were pandrug resistant. High resistance rates were observed against penicillins and cephalosporins, moderate rates against fluoroquinolones, and lowest rates against the carbapenems. All gram-positive bacteria were sensitive to linezolid. Increased severity of chronic obstructive pulmonary disease was related to increased prevalence of antibiotic resistance. The predominant bacterial pathogens for AECOPD in Upper Egypt are H. influenzae, S. pneumoniae, and K. pneumoniae. Bacterial resistance rates were the highest against penicillins and cephalosporins, moderate against fluoroquinolones, and least against carbapenems. Increased severity of chronic obstructive pulmonary disease is related to an increased prevalence of antibiotic resistance.

Recent Advancements in Antimycobacterial and Antifungal Drugs: A Patent Perspective

Infections caused by Mycobacterium and pathogenic fungi have risen drastically over the past few decades. Moreover, with the increase in the number of immunocompromised (burn, organ transplant, chemotherapy, HIV) patients, these bacterial and fungal infections have led to alarming mortality rates. The drugs currently in use have become relatively ineffective due to ever increasing phenomenon of multidrug resistance. Furthermore, these drugs suffer with severe toxicity effects and also lack cost effectiveness. Under such compelling circumstances, it is pertinent to find novel and safer drugs with improved properties. One strategy that could be adopted is to identify natural bioactive compounds having antimicrobial potential with minimal side effects. Alternatively, drugs synthesized with the help of combinatorial chemistry leading to enhanced antimicrobial properties could be another strategy. This article summarizes at a common platform the current scenario of the available natural as well as synthetic drugs targeting cell envelope that have patentable therapeutic interventions against predominant human bacterial and fungal pathogens.

Predominant Bacteria Detected from the Middle Ear Fluid of Children Experiencing Otitis Media: A Systematic Review.

BackgroundOtitis media (OM) is amongst the most common childhood diseases and is associated with multiple microbial pathogens within the middle ear. Global and temporal monitoring of predominant bacterial pathogens is important to inform new treatment strategies, vaccine development and to monitor the impact of vaccine implementation to improve progress toward global OM prevention.MethodsA systematic review of published reports of microbiology of acute otitis media (AOM) and otitis media with effusion (OME) from January, 1970 to August 2014, was performed using PubMed databases.ResultsThis review confirmed that Streptococcus pneumoniae and Haemophilus influenzae, remain the predominant bacterial pathogens, with S. pneumoniae the predominant bacterium in the majority reports from AOM patients. In contrast, H. influenzae was the predominant bacterium for patients experiencing chronic OME, recurrent AOM and AOM with treatment failure. This result was consistent, even where improved detection sensitivity from the use of polymerase chain reaction (PCR) rather than bacterial culture was conducted. On average, PCR analyses increased the frequency of detection of S. pneumoniae and H. influenzae 3.2 fold compared to culture, whilst Moraxella catarrhalis was 4.5 times more frequently identified by PCR. Molecular methods can also improve monitoring of regional changes in the serotypes and identification frequency of S. pneumoniae and H. influenzae over time or after vaccine implementation, such as after introduction of the 7-valent pneumococcal conjugate vaccine.ConclusionsGlobally, S. pneumoniae and H. influenzae remain the predominant otopathogens associated with OM as identified through bacterial culture; however, molecular methods continue to improve the frequency and accuracy of detection of individual serotypes. Ongoing monitoring with appropriate detection methods for OM pathogens can support development of improved vaccines to provide protection from the complex combination of otopathogens within the middle ear, ultimately aiming to reduce the risk of chronic and recurrent OM in vulnerable populations.

Characterizing the pathotype of neonatal meningitis causing Escherichia coli (NMEC).

BackgroundNeonatal meningitis-causing Escherichia coli (NMEC) is the predominant Gram-negative bacterial pathogen associated with meningitis in newborn infants. High levels of heterogeneity and diversity have been observed in the repertoire of virulence traits and other characteristics among strains of NMEC making it difficult to define the NMEC pathotype. The objective of the present study was to identify genotypic and phenotypic characteristics of NMEC that can be used to distinguish them from commensal E. coli.MethodsA total of 53 isolates of NMEC obtained from neonates with meningitis and 48 isolates of fecal E. coli obtained from healthy individuals (HFEC) were comparatively evaluated using five phenotypic (serotyping, serum bactericidal assay, biofilm assay, antimicorbial susceptibility testing, and in vitro cell invasion assay) and three genotypic (phylogrouping, virulence genotyping, and pulsed-field gel electrophoresis) methods.ResultsA majority (67.92 %) of NMEC belonged to B2 phylogenetic group whereas 59 % of HFEC belonged to groups A and D. Serotyping revealed that the most common O and H types present in NMEC tested were O1 (15 %), O8 (11.3 %), O18 (13.2 %), and H7 (25.3 %). In contrast, none of the HFEC tested belonged to O1 or O18 serogroups. The most common serogroup identified in HFEC was O8 (6.25 %). The virulence genotyping reflected that more than 70 % of NMEC carried kpsII, K1, neuC, iucC, sitA, and vat genes with only less than 27 % of HFEC possessing these genes. All NMEC and 79 % of HFEC tested were able to invade human cerebral microvascular endothelial cells. No statistically significant difference was observed in the serum resistance phenotype between NMEC and HFEC. The NMEC strains demonstrated a greater ability to form biofilms in Luria Bertani broth medium than did HFEC (79.2 % vs 39.9 %).ConclusionThe results of our study demonstrated that virulence genotyping and phylogrouping may assist in defining the potential NMEC pathotype.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-015-0547-9) contains supplementary material, which is available to authorized users.

Lower respiratory tract infections among HIV positive and control group in Nepal.

Lower respiratory tract infections (LRTIs) are the most frequent respiratory diseases among HIV infected patients and are frequently the first clinical manifestations of the HIV infections. LRTIs are common not only among the HIV seropositive cases but also the commonest domiciliary and nosocomial infections among the general population. The present study was carried out to determine the comparative prevalence of common bacterial and fungal organism among the HIV positive and control population. This cross sectional study was conducted among 220 people attending National Public Health Laboratory, Kathmandu, Nepal. Out of them 120 were HIV sero-positive and rest were HIV sero-negative. Sputum samples were collected and processed soon after its collection. Macroscopic examination was done to determine the sample integrity. Gram stain, AFB stain and KOH preparation was performed for preliminary identification of the pathogens. Culture was carried out for bacterial and fungal pathogens. Antibiotic susceptibility test (Kirby-Bauer disc diffusion method) was performed from the isolated organisms. The 85 out of 120 HIV sero-positive patients were found to be infected with one or more microbial pathogens. The overall infection rate was found to be significantly lower in HIV seronegative people (27%). Among HIV seropositive cases prevalence of LRTIs was strongly associated with lower CD4 counts (<200/mm(3)). The prevalence of mycobacterium tuberculosis was found to be 10% among HIV/AIDS patients which was significantly higher than among the non-HIV cases (3%). The bacterial pathogens was observed among 46.6% of HIV positive and 22.0% of HIV negative people. Among the positive cases, K. pneumoniae was the predominant bacterial pathogens, followed by E. coli and S. pneumoniae. C. albicans was found to be predominant fungal pathogen followed by Aspergillus spp. germ tube negative Candida spp. and Penicillium spp. Similar types of organisms were found to be associated with LRTIs among HIV positive and negative people. The prevalence of both fungal and bacterial infections was significantly higher among HIV seropositive people than HIV seronegative people. All in all, lower respiratory tract illness is significantly higher in HIV/AIDS cases than in HIV seronegative cases.

Spectrum and management of complement immunodeficiencies (excluding hereditary angioedema) across Europe.

Complement immunodeficiencies (excluding hereditary angioedema and mannose binding lectin deficiency) are rare. Published literature consists largely of case reports and small series. We collated data from 18 cities across Europe to provide an overview of primarily homozygous, rather than partial genotypes and their impact and management. Patients were recruited through the ESID registry. Clinical and laboratory information was collected onto standardized forms and analyzed using SPSS software. Seventy-seven patients aged 1 to 68 years were identified. 44 % presented in their first decade of life. 29 % had C2 deficiency, defects in 11 other complement factors were found. 50 (65 %) had serious invasive infections. 61 % of Neisseria meningitidis infections occurred in patients with terminal pathway defects, while 74 % of Streptococcus pneumoniae infections occurred in patients with classical pathway defects (p < 0.001). Physicians in the UK were more likely to prescribe antibiotic prophylaxis than colleagues on the Continent for patients with classical pathway defects. After diagnosis, 16 % of patients suffered serious bacterial infections. Age of the patient and use of prophylactic antibiotics were not associated with subsequent infection risk. Inflammatory/autoimmune diseases were not seen in patients with terminal pathway, but in one third of patients classical and alternative pathway defects. The clinical phenotypes of specific complement immunodeficiencies vary considerably both in terms of the predominant bacterial pathogen, and the risk and type of auto-inflammatory disease. Appreciation of these phenotypic differences should help both immunologists and other specialists in their diagnosis and management of these rare and complex patients.

Prevalence of Urinary Tract Infection, Microbial Aetiology, and Antibiotic Sensitivity Pattern among Antenatal Women Presenting with Lower Abdominal Pains at Kenyatta National Hospital, Nairobi, Kenya

Objective. To determine the prevalence of urinary tract infection as a cause of lower abdominal pains among antenatal women and its aetiological microorganism and define the sensitivity pattern to commonly used antibiotics. Study Design. A cross sectional study. Setting. Kenyatta National Hospital, Nairobi, Kenya. Subjects. One hundred and fifty antenatal women. Main Outcome Measures. Overall the prevalence of urinary tract infection, its aetiological causes, and antibiotic sensitivity pattern. Results. The prevalence of UTI among antenatal women presenting with lower abdominal pains in Kenyatta National Hospital was found to be 26.7%. Of the 40 women with positive culture urine, 31 (C77.8%) were also positive on dipstick and 27 (67.5%) were positive on urine microscopy. There is significant correlation between urine dipstick testing, urine microscopy, and positive urine culture in UTI. Dipstick test and urine microscopy test had high sensitivity and specificity in screening for UTI. The predominant bacterial pathogens were Escherichia coli at 40% followed by Staphylococcus spp. at 25% and Klebsiella spp. at 10%. There were also Enterococcus, Enterobacter, and Citrobacter species. The isolated gram-negative bacteria were 100% sensitive to meropenem, imipenem, augmentin, ceftazidime, and levofloxacin and about 81% to cefuroxime. The bacteria showed significant resistance to gentamycin and ampicillin of up to 80%. The isolated gram-positive bacteria were 100% sensitive to augmentin, cefuroxime, ceftriaxone, ceftazidime, meropenem, and imipenem but showed significant resistance to levofloxacin, gentamycin, nitrofurantoin, and ampicillin of between 20% and 80%.

Non Chlamydial Acute Bacterial Conjunctivitis in Sudanese Children

In children there is a paucity of data in recent literature on the prevalence of infective conjunctivitis and almost it is absent from an area like Sudan. This research was aimed to study the point prevalence of a cute bacterial conjunctivitis in Sudanese children and put light on causative bacterial pathogens. Acute bacterial conjunctivitis is a common infection in children and it may be extremely contagious and easily spread in day care centres and school class rooms leading to absences or lost time from work for parents, outbreaks may occur. Common presenting symptoms are red eye and eye discharge. Commonly involved bacteria are Staphylococcus aureus and Haemophilus influenzae. Generally it is a mild disease but more serious complications may occur. Methods: Hundred children with clinical presentation of acute conjunctivitis were included in this study. For each patient a sample for bacterial culture and sensitivity to commonly used antibiotics was obtained by a thin cotton micro swab, isolation and identification of pathogens was done by conventional methods. Antimicrobial susceptibility testing was performed according to method standardized by CLSI. Data was analyzed by SPSS computer program. Results: The most common presenting symptom is the red eye. Bacterial pathogens were detected in 65% of the studied sample. Predominant bacterial pathogens were Staphylococcus aureus and Haemophilus influenzae, Klebsiella pneumoniae is a cause in small number of patients. All isolates are sensitive to Gentamycin. Conclusion: Acute bacterial conjunctivitis is a common infection in children, muco purulent discharge points to bacterial cause in acute infective conjunctivitis. Staphylococcus aureus is a common pathogen and it is sensitive to Gentamycin.

The Bacterial Isolates and Plasmid Profile of Extended Spectrum Beta-Lactamases Producers Causing Urinary Tract Infection among Pregnant Women in Uyo, Nigeria

Background: Extended spectrum beta-lactamases (ESBLs) are enzymes that compromise the efficacy of all beta-lactams and are spread by plasmids. They are of public health importance the world over; however, in Nigeria in general and Uyo in particular, tests for their detection are not routinely done in hospital laboratories despite increase in treatment failures observed for common clinical conditions like urinary tract infection. Objective: To isolate ESBLs producing uropathogens and the plasmid underlying their resistance to antibiotics. Materials and Methods: Three hundred urine specimens (n = 300) were collected from pregnant women attending antenatal clinics at St. Lukes Hospital, Anua, cultured and incubated according to accepted standard. Identification of isolates was done using Microbact 24E (Oxoid, UK) system. The predominant bacterial pathogens were Escherichia coli (42%) followed by Klebsiella pneumonia (21%), Klebsiella oxytoca (12%), Citrobacter spp. (5%), Proteus mirabilis (7%), Enterobacter spp. (12%) and Acinetobacter baumanii (1%). The isolated bacteria were tested for their antibiotic susceptibility using Clinical Laboratory Standard Institute (CLSI) recommended disc diffusion method. A Double Disk Synergy Test (DDST) and Phenotypic Disk Confirmatory Test (PDCT) were performed to determine ESBL production. Chromagar ESBL was also used to test for the presence of ESBL producing isolates. The plasmid content of ESBL producing isolates and their participation in drug resistance were investigated. Results: Of the 80 bacterial isolates causing urinary tract infection in these women, the ESBL producers were found to be 16 (20%). Out of these 16 ESBL producing urogenital isolates Klebsiella pneumonia (8, 50%) was the most prevalent. Others include Escherichia coli (38%), Klebsiella oxytoca (6%) and Enterobacter cloacae (6). Plasmid content of ESBL producing isolates was found to be 87.5%. Conclusion: The Extended Spectrum Beta-lactamase producing uropathogens mainly of plasmid origin are increasingly responsible for the cause of community acquired urinary tract infections in pregnant women in Uyo.