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Antibiotic resistance and ndvB gene expression among biofilm producing Pseudomonas aeruoginosa isolates

N.A. Mohammed, I.M. Abd Alla

 

Abstract

A novel antibiotic resistant mechanism among biofilms is glucan-mediated sequestration in which ndvB gene encodes a glucosyltransferase involved in the formation of this glucans. We studied the biofilm formation and antibiotic susceptibility pattern of P. aeruginosa isolated from clinical samples, and measured the expression of ndvB gene among biofilm forming isolates and their planktonic counterparts. The study was conducted on 92 P. aeruginosa isolates. Biofilm was measured using tissue culture plate method. Antibiotic susceptibility of biofilm positive isolates and planktonic counterparts for ciprofloxacin, tobramycin and gentamycin was tested using tube microdilution method. Expression of ndvB gene was measured using Syper green real time PCR. We found that 44 isolates (47.8%) of P. aeruginosa were biofilm positive. The biofilm formation was high among urine, endotracheal tube aspirate and burn isolates compared to isolates of wound specimens, with statistically nonsignificant differences. None of biofilm forming isolates was susceptible to the 3 antibiotics compared to the presence of susceptible isolates among the planktonic counterpart (18/40.9% for ciprofloxacin, 12/27.3% for tobramycin and 13/29.5% for gentamycin). Expression of ndvB gene was significantly high in biofilm isolates than their corresponding counterpart, with significant correlations with minimal biofilm inhibitory concentration (MBIC) values of cibrofloxacin (r=+ 0.65, p< 0.05 ), tobramycin (r= + 0.54 p< 0.05 ) and gentamycin (r=+ 0.77, p< 0.001 ).From this study we concluded that biofilm formation is an important character of P. aeruginosa that is a main cause of antibiotic resistance especially in isolates from catheterized urine , wound and endotracheal tube aspirate. NdvB gene expression is a mechanism of resistance to antibiotics in P. aeruginosa biofilms.

Keywords: P. aeruginosa, biofilm, antibiotic resistance and ndvB gene

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Antibiotic resistance and ndvB gene expression among biofilm producing Pseudomonas aeruoginosa isolates

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Molecular detection of salmonella species from selected vegetables sold in a north-central Nigerian setting

D.S. Adeniyi, T.M. Akindigh, F.N. Aniweta, H.J. Zumbes, A.J. Anejo-okopi

 

Abstract

It is vital to study and understand the genetic basis to the virulence of different Salmonella strains in other to fully grasp the facts behind the unique capabilities of these pathogenic agents to causing diseases in both humans and animals. In this study, the conventional microbiological culture methods were used to isolate pure Salmonella strains from 120 vegetable samples of five different types; which were all obtained at seven different popular markets in the Jos Metropolis of North Central Nigeria. 25 (20.8%) pure isolates were obtained from 120 samples after initial culture and sub-cultures; with 24 (20%) of the pure isolates testing positive as being pathogenic after biochemical analysis. From the 25 pure isolates, the same 24 which tested positive for biochemical tests were also successfully amplified by PCR technique with the SalmonellainvA virulence gene. The result shows that 96% of the pure isolates were positive for the Salmonella invA gene. The PCR product which was very specific is a 250bp fragment of DNA which was visualized in 1.5% agarose gel. This finding shows that virulent Salmonella strains pose a major health hazard and public health concern to the affected population. Our study shows that there is a high prevalence rate of virulent Salmonella strains in North-Central Nigeria. It is thus concluded that although both the conventional culture and biochemical methods of isolating Salmonella species are most useful for obtaining pure isolates and identifying pathogenic strains, however, the PCR technique remains the most specific and sensitive; especially when the rapid identification and detection of virulent strains of Salmonella species are of utmost importance.

Keywords: Virulence, invA gene, PCR, North Central Nigeria

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Molecular detection of salmonella species from selected vegetables sold in a north-central Nigerian setting

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Prevalence of methicillin-resistant Staphylococcus aureus and extended spectrum β–lactamase producers among bacteria isolated from infected wounds in a tertiary hospital in Ibadan City

O.S. Alabi, A.O. Obisesan, A.A. Ola

 

Abstract

Wound colonization by microorganisms is most frequently polymicrobial and incidences of high level resistance among bacterial isolates from wounds have been reported. Methicillin-resistant Staphylococcus aureus (MRSA) and extendedspectrum beta-lactamase (ESBL) producing Gram-negative bacteria both constitute serious challenge to physician in their choice of antibiotic treatment of infections caused by these bacteria. This study determined the antibiotic susceptibility profiles and prevalence of MRSA and ESBL producers among wound bacterial isolates from a tertiary hospital in Ibadan City.

Forty (40) clinical bacterial isolates from five wound sources were collected from the Microbiology unit of the University College Hospital (UCH), Ibadan and were authenticated with standard bacteriological techniques. Antibiotic susceptibility test was done by disc-diffusion method using 19 antibiotics belonging to 12 classes. MRSA strains were detected by their resistance to cefoxitin and/or oxacillin antibiotics. Presumptive ESBL production was by double-disc synergy test using 30 μg cefotaxime and ceftazidime around 20/10 μg amoxicillin-clavulanic acid discs. ESBL confirmation was by minimum inhibitory concentration (MIC) using agar-dilution method.

The authenticated isolates include Proteus spp (47.5%), Staphylococcus aureus (27.5%), Pseudomonas aeruginosa (12.5%), Klebsiella spp (7.5%), Acinetobacter baumanii (2.5%) and E. coli (2.5%). Distribution of the isolates collected according to wound sources includes: acute soft tissue wounds (35%), leg ulcer (32.5%), surgical wounds (17.5%), burn wounds (12.5%) and diabetic foot ulcer (2.5%). Distributions according to patients’ gender are: male (65%), female (35%), and according to age-groups are: 0 – 19 years (22.5%), 20 – 39 years (35%), 40 – 59 years (32.5%) and ≥ 60 years (10%). All (100%) the isolates were multidrug resistant (MDR) being resistant to ≥ 3 classes of antibiotics. Percentages of isolates resistance to each of the antibiotic include: piperacillin, piperacillin tozobactam and amoxicillin-clavulanic acid were 100%, ceftazidime, cefuroxime, cefixime, aztreonam, sulphamethoxazole-trimethoprim, erythromycin, chloramphenicol and doxycyclin were > 70%, cefoxitin (62.5%), Nitrofurantion (52.5%), ciprofloxacin (45%), ofloxacin (35%), perfloxacin (37.5%), gentamicin (32.5%) and imipenem (2.5%). Of the 11 Staphylococcus aureus collected, 54.5% were detected to be MRSA strains while ESBL production was detected in 55.2% of the Gram negative isolates.

This study revealed 100% MDR phenotype constituting high level of MRSA strains (54.5%) and ESBL producers (55.2%) among Gram-positive and Gram-negative bacterial wound isolates respectively. Hence, this calls for caution in the use of extended spectrum antibiotics in treating patients with infected wounds.

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Prevalence of methicillin-resistant Staphylococcus aureus and extended spectrum β–lactamase producers among bacteria isolated from infected wounds in a tertiary hospital in Ibadan City

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Nosocomial imipenem-resistant Acinetobacter baumannii infections in intensive care units: incidence and risk factors assessment

Hend E. Sharaf, Marian A. Gerges

 

Abstract

Imipenem-resistant Acinetobacter baumannii (A. baumannii) (IRAB) has emerged as a challenging nosocomial pathogen particularly in intensive care units (ICUs). Studying the risk factors associated with IRAB infection is of paramount importance for appropriate control of IRAB spread. The aim of this study was to assess the incidence rate and possible risk factors associated with nosocomial IRAB infections in ICUs. A prospective cohort study was carried out in surgical and emergency ICUs of a tertiary care hospital in Egypt. All patients who developed nosocomial A. baumannii infection from the start of January 2014 to the end of December 2015 were included. Isolates were identified as A. baumannii using API 20NE and E-test was used to define IRAB. Out of 146 A. baumannii isolates, 11 were found to be IRAB (7.5% incidence rate), of them 72.7% (8/11) were found to be multidrug resistant (MDR). Univariate analysis demonstrated that hospital stay before ICU admission [Relative risk (RR) 3.51, 95% confidence interval (CI) 1.0- 12.7, P= 0.04)], longer ICU stay (P= 0.005), exposure to emergent surgery (RR 17.5, CI 7.39-41.4, P= 0.000), the presence of central venous catheter (RR 3.26, CI 1.0-10.6, P= 0.04) and previous carbapenem use (RR 4.05, CI 1.12-14.6, P =0.02) were significant risk factors for IRAB infection. In conclusion, a relatively high IRAB incidence was recorded in ICUs of our hospital. Hospital stay before ICU admission, longer ICU stay, exposure to emergent surgery, the presence of central venous catheter and previous carbapenem use were significant risk factors for IRAB infection. Rationale use of carbapenems in ICUs should be considered.

Keywords: Imipenem-resistant, Acinetobacter baumannii, Intensive care units

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Nosocomial imipenem-resistant Acinetobacter baumannii infections in intensive care units incidence and risk factors assessment

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Evaluation of methicillin-resistant Staphylococcus aureus nasal carriage in Malagasy veterinary students

T Rasamiravaka, A.J. Nirinarimanana, A Rasamindrakotroka

 

Abstract

Purpose: Populations that are frequently in contact with animals such as veterinary students have been demonstrated to be at risk of MRSA carriage.Thus, it is relevant to generate baseline data in MRSA nasal carriage and multidrug resistance among Malagasy veterinary students (Madagascar).

Method: A cross-sectional study was carried out among veterinary students coming for laboratory training. After their wise consent, nasal swabs of the anterior nares were carried out; and S. aureus was isolated by selective chromogenic culture. They were then assessed for antimicrobial susceptibility.

Results: Nasal swabs of 155 Malagasy veterinary students (Sex-ratio M/F: 0.91), enabled to isolate 30 (19, 35%) S. aureus strains, among which 14 (46, 66 %) were méthicillin-resistant (MRSA). Risk factors analysis revealed that history of hospitalization, recent antibiotic intake and frequent contact with animals and livestock workers/veterinarians increase the risk of MRSA nasal carriage. Among MRSA nasal isolates, a high rate of multidrug resistance and particularly an intriguing resistance to gentamycin (20%) and vancomycin (7.14%) were observed.

Conclusion: These results suggest that MRSA is spreading in Malagasy community requiring a strategic policy against multidrug resistant strains.

Keywords: Madagascar, MRSA, Risk factors, Veterinary

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Evaluation of methicillin-resistant Staphylococcus aureus nasal carriage in Malagasy veterinary students

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Occurrence of unusual non-fermentative gram negative bacilli in intensive care units of a university hospital, Egypt

E.M. EL-Behedy, M Hend, MM EL-Arini, M.A. Gerges, N.A.E. Mohamed, N.M. Gamil

 

Abstract

Non-fermentative Gram-negative bacilli (NFGNB) other than Pseudomonas and Acinetobacter species have emerged as nosocomial pathogens. No much data is currently available concerning the occurrence of these types of bacteria in Zagazig University Hospitals (ZUHs). In this study, the occurrence as well as the antimicrobial susceptibility pattern of unusual NFGNB obtained from clinical samples collected from intensive care units (ICUs) of ZUHs was assessed. Additionally, the genetic relatedness among the most prevalent unusual NFGNB species was studied.

Results: Out of 516 non-repeated clinical sample, 97 NFGNB (18.7%) were isolated. Among them, 17 unusual NFGNB were identified by API 20NE, accounting for 17.5% of NFGNB and 3.3% of all tested samples. Within the unusual NFGNB, Burkholderiacepaciacomplex (Bcc) was the most prevalent species accounting for 94.1% of NFGNB and 3.1% of total samples. This was followed by Burkholderia pseudomallei (B. pseudomallei) which accounted for 5.9% of NFGNB and 0.2% of all obtained specimens. Tigecycline antibiotic was the most effective antibiotic against Bcc isolates (68.8% susceptibility) in disc diffusion method. After random amplified polymorphic DNA (RAPD) testing, the obtained Bcc isolates were found to be genetically diverse. This highlights Bcc as an emerging nosocomial pathogen in ICUs of ZUHs. Continuous monitoring of the occurrence of Bcc in ICU as well as in other hospital wards is warranted.

Keywords: Unusual, Non-fermentative, gram-negative bacilli, intensive care unit

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Occurrence of unusual non-fermentative gram negative bacilli in intensive care units of a university hospital, Egypt

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A survey of malaria prevalence and antimalarial preventive measures amongst students of University of Lagos, Nigeria

T.S. Olusegun-Joseph, M.A. Oboh, M.U. Uduak

 

Abstract

The prevalence of malaria parasite and antimalarial preventive measures among students of University of Lagos, Nigeria was carried out between November 2014 and February 2015. Blood samples were collected from 400 students (with age ranging from 15-46year) by finger pricking and analyzed microscopically and by Rapid Diagnostic Test kit. Semi-structured questionnaire probing into their knowledge of the cause of malaria, ability to recognize signs and symptoms, treatment seeking behaviour was distributed to the respondents. The prevalence of Plasmodium falciparum by microscopy was significantly lower (p=0.0000042). More than three quarters of the respondents (88.5%) had a good knowledge of the cause of malaria and were able to identify signs and symptoms of malaria which included headache (51.5%), fever (26%), dizziness (9.5%). Also more than half of the students (202) visit hospital when they recognize such signs while others visit Pharmaceutical outlets (130), drug hawkers (37) or use herbal remedy (31).Malaria preventive measures employed by students ranges from the use of Long-Lasting Insecticide Treated Bednets (74), topical mosquito repellant cream (65) to cleaning the environment (54). Furthermore, half of the students (50%) reported having malaria bouts twice per year, 35% once annually while 15% could not remember how often they have it. These bouts of various frequencies resulted in 360 (90%) of the students being absent from school from less than 10 days to more than 20 days. Proactively placing preventive measures would negate cascades of effects amongst the students. Continuous studies should be carried out to assess the prevalence of malaria in different foci of Nigeria and the level of awareness on the benefits of use of preventive measures should be emphasized among community members if Nigeria and Africa as a whole will meet the elimination target by 2030.

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A survey of malaria prevalence and antimalarial preventive measures amongst students of University of Lagos, Nigeria

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Haematological profile of HIV seropositive HAART naive clients in Kogi State University Teaching Hospital, Anyigba, Kogi State. Nigeria

O.J. Alabi, S.P.O. Akogu, M Akpa, V Ukeje, P.O. Okpanachi, O.G. Agama, S Gideon, B Adegboro

 

Abstract

Examination of haematological profile is useful for baseline assessment, treatment monitoring and prognostic evaluation in Hiv/AIDS management. The objectives of the study was to assess the haematological profile of HIV seropositive HAART naive patients who attended Kogi State University Teaching Hospital, Anyigba, Kogi State, Nigeria between January 1, 2014 and December 31, 2014. The study was prospective experimental research. Ethical clearance was obtained from ethical committee of Kogi State University Teaching Hospital, Anyigba. Written and verbal informed consent was taken from all patients. A total of 404 HIV seropositive HAART naive patients comprising 147 (36.4%) males and 257(63.6%)females were examined. The overall mean age of patients was 33.0 ±12.7 years and female-male ratio was 1.7: 1. Half of respondents 200(50.4%) accessed HIV care and treatment for the time in stage three HIV disease. Patients had overall mean CD4 cells count of 381.8 ± 240.8 cells/mm3 , white blood cells count of 5.8 ± 3.6 × 109/L, lymphocyte count 2.3 ±1.3, granulocyte count 0.8 ± 0.8 and platelet count of 260.0 ± 109.1 × 109/L. The mean packed cell volume was 34.1± 5.9 %, haemoglobin 11.3 ± 2.1 g/dl and mean corpuscular haemoglobin concentration was 31.5 ± 14.3 g/dl. The packed cells volume (p=0.0001, T test= 4.0259) and haemoglobin (p=0.0001, T test= 4.1534) profiles of HIV clients were respectively statistically significance with gender, while CD4 cells count ( p=0.004, F= 4.523) and platelet count (p= 0.008, F = 3.974) were significance respectively with HIV disease staging. The study recommended the need for awareness programs, nutritional education and micronutrients supplementation including multivitamins for HIV clients.

Keywords: Haematological, HIV, HAART, patients, KSUTH, Nigeria

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Haematological profile of HIV seropositive HAART naive clients in Kogi State University Teaching Hospital, Anyigba, Kogi State. Nigeria

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Review of Lassa fever, an emerging old world haemorrhagic viral disease in sub-Saharan Africa

O Azeez-Akande

 

Abstract

Lassa fever is an acute immunosuppressive illness of increasing public health concern causing severe morbidity and significant mortality (Case fatality rate (CFR) ≥ 50%) especially in epidemic cases. Although Lassa fever has emerged (following its first detection (1969) in Lassa town, Nigeria) as one of the most prevalent and debilitating viral haemorrhagic fevers endemic in West Africa region (Nigeria inclusive), yet, the control/prevention of the regular outbreak of the disease has become an herculean task in the areas affected; there is inadequate healthcare facility (including Laboratory/diagnostic and care centres), poor socioeconomic environment, lack of awareness among the populace and presence of favourable ecologic niche for the survival and propagation of the natural host and reservoir mouse (Mastomys natalensis) of Lassa virus . Lassa fever is mainly transmitted by contact with excretions and secretions of infected rats via foods and water as well as exposure to other contaminated items. Lassa virus is a member of an Old World Arenariruses, of family Arenaviridae. It is an enveloped, single-stranded (SS) bisegmented RNA virus with ability to replicate very rapidly. It consists of 4 lineages; 3 members are identified as ancenstral strains found in Nigeria, while the fourth is domiciled in other West Africa Countries. Lassa virus infects almost every tissue in human body resulting in multisystemic dysfunction. The incubation period is generally between 6 to 21 days resulting in 3 stages of clinical manifestation viz: Acute phase characterized by flu-like, non-specific illness; haemorrhagic phase accompanied with gastrointestinal symptoms and cardiovascular/neurologic complications. Currently, there is no clinically certified Lassa fever vaccine thus complicating deterrent or preventive measures. Hence, there is need for intensification of educational programs for the populace on the useful control measures against Lassa fever. The stakeholders need to prioritize intervention and support program and also speed up the processes leading to the production of effective vaccine to limit the menace of Lassa fever outbreak and associated morbidity, fatality and high socio-economic cost.

Keywords: Lassa fever, endemic, epidemic, reservoir rodent, West Africa

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Review of Lassa fever, an emerging old world haemorrhagic viral disease in sub-Saharan Africa

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Occurrence of malaria and utilization of antimalaria preventive measures amongst pregnant women attending Ajeromi- Ifelodun General Hospital, Lagos State, Nigeria

M.A. Oboh, E.T. Idowu, M.K. Oyebola, Y.A. Olukosi, O.A. Otubanjo, M.A. Mafe

 

Abstract

Malaria in Pregnancy poses a serious health problem both for the mother and her unborn baby and this can be prevented with the use of Intermittent Preventive Treatment with sulphadoxine pyrimethamine (IPTp-SP), Long Lasting Insecticidetreated Nets (LLIN) and other preventive measures. This cross-sectional survey was carried out among pregnant women attending Ajeromi Ifelodun General Hospital between August 2013 and February 2014. A total of 414 pregnant women (with mean age of 29±8.7) in their first (84), second (124) and third (206) trimesters were recruited for this study. Blood samples for making both thin and thick smears were collected and semi-structured questionnaires administered to the respondents. The questionnaire probed into their knowledge on cause of malaria, the preventive measures taken against mosquito bite, use of IPTp-SP, possession and use of LLIN. The overall prevalence of malaria due to Plasmodium falciparum is 24 (5.8%) out of which 13 were primigravid, 5 were secundi-gravid, and 6 were multigravida with no significant difference (P>0.05) amongst them. Two hundred and eighty-six (69.1%) pregnant women had good knowledge of the cause of malaria. 164 (39.6%) of the sampled population had a tertiary education while 182 (44.0%) had secondary education, 124 (30.4%) were traders and 80(19.6%) were civil servants. Preventive measures claimed to be adopted by the respondents in avoiding mosquito bites include the use of LLIN (62.6%), insecticides sprays (36.2%), and locally adopted measures (1.5%). The number of respondents who had not availed themselves of IPTp-SP was significantly higher 258 (62.3%) compared to those who had (P<0.05). It was observed that educational status had no significant effect on the knowledge of the cause of malaria in sample population (p>0.05). The findings of this study reveal that there is a good knowledge on the cause of malaria among pregnant women but low use of IPTp-SP. In order to meet the new target of reaching an elimination stage set by the World Health Organization, factors responsible for the low use of these preventive measures should be investigated and quickly addressed so as to reduce both maternal and child morbidity/mortality resulting from malaria infection.

Keywords: Malaria, Pregnant women, Prevention, Intermitent preventive treatment, Sulphadoxine-pyrimethamine, Longlasting Insecticide treated net

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Occurrence of malaria and utilization of antimalaria preventive measures amongst pregnant women attending Ajeromi- Ifelodun General Hospital, Lagos State,